TypoSoil User Manual - For Soils Hydrostructural Characterization

Abstract

The work presented in this document was realized in the frame of the Food Water Energy Nexus (NEF) program of QEERI in 2011 () of which the soil is the hidden part at the hearth of the nexus for developing a sustainable management of the resources, of which water and energy, and to give solutions for optimizing the food production.
So the first goal of our “Natural Environment modeling team” was to create a soil laboratory named Hydrostructural Pedology which is based on three main activities, all linked together:
1) Characterization of the physical properties of organization of the soil medium, its structure and its hydrostructural properties;
2) Mapping of “soil primary mapping units” that are considered homogeneous from the point of view of their internal organization (represented by the representative pedon and its horizons) and the hydrostructural properties of their horizon, each represented by its pedostructure (characterized in 1 above);
3) The physical modeling of the pedon and its internal organization as the growing medium for living organisms and plants in the critical zone. The pedon and its horizons are the solid part, structured, mappable, of the soil-plant-atmosphere system, Structural Representative Elementary Volume (SREV) of the soil primary mapping unit.
These 3 activities are established in a same unifying paradigm which is the systemic and thermodynamic approach of the natural medium initiated by Braudeau and Mohtar (2009). They turn around an hydrostructural characterization of the pedostructure that should provide the thermodynamic parameters of the two state equations of the soil medium: namely the pedostructure shrinkage curve V(W) and the pedostructure water retention curve h(W). It was for meeting the measurement requirements of this approach that the TypoSoil™ device was recently designed by Valorhiz and IRD (Bellier and Braudeau, 2011). It constitutes the only one actually existing in soil science that allows for a an accurate determination of the pedostructural parameters that are the identity of the soil horizons.

Full text

TYPOSOIL® USER MANUAL
For Hydrostructural Characterization of the Soil
Prepared by the Natural Environment Modeling Team of QEERI
(Qatar Environment and Energy Research Institute)

1 Braudeau, E., Mohtar, R., 2009. Modeling the soil system: Bridging the gap between pedology and soil-water
physics. Global Planetary Change Journal 67, 51-61. http://dx.doi.org/10.1016/j.gloplacha.2008.12.002
2 Bellier, G., Braudeau, E. 2013. Device for measurement coupled with water parameters of soil. WO
2013/004927 A1. World Intellectual Property Organization, WIPO.
Foreword
The work presented in this document was realized in the frame of the Food-Water-Energy Nexus (NEF) program of
QEERI, began in 2011, of which the soil is the essential hidden part at the foundation of the nexus for developing a
sustainable management of the resources, of which water and energy, and to give solutions for optimizing the
food production.
The first aim of our “Natural Environment Modeling Team” was to create a Hydrostructural Pedology soil
laboratory focusing on three main activities, all linked together:
1) Characterization of the physical properties of the organization of the soil medium, its structure and its
hydrostructural properties;
2) Mapping of “soil primary mapping units” that are considered homogeneous from the point of view of their
internal organization (denoted by the representative pedon and its horizons) and the hydrostructural properties of
their horizon, each represented by its pedostructure (characterized in 1, above);
3) The physical modeling of the pedon and its internal organization as the growing medium for living organisms
and plants in the critical zone. The pedon and its horizons are the structured, mappable, solid portion, of the soil-
plant-atmosphere system, delimited by the Structural Representative Elementary Volume (SREV) of the soil
primary mapping unit.
These three unifying activities are established in a same unique paradigm centered on the systemic and
thermodynamic approach of the natural medium initiated by Braudeau and Mohtar (2009)1. They reveal a
hydrostructural characterization of the pedostructure that provides the thermodynamic parameters of the two
state equations of the soil medium: namely the pedostructure shrinkage curve V(W) and the pedostructure water
retention curve h(W). It was for meeting the measurement requirements of this approach that the TypoSoil™
device was recently designed by Valorhiz and IRD (Bellier and Braudeau, 2011)2. The TypoSoil™ constitutes the only
apparatus existing in soil science that allows for an accurate determination of the pedostructural parameters that
provide the distinctive identity of the soil horizons.
The following document is composed of 6 sections about the soil preparation, the apparatus description and
running, the methodology of measurement and, finally, an example of one experiment executed to demonstrate
that the variation of the temperature between 25⁰C and 40⁰C in the measurement chamber has no effect on the
pedostructural water retention curve.
The Authors-
QEERI, Natural Environment Modeling Team, May 2013
Erik Braudeau - Principal Investigator
Rabi H. Mohtar - Executive Director of QEERI
Amjad Assi - Ph.D. Candidate QEERI/Purdue University
Josh Accola - M. S. Student QEERI/University of Wisconsin-Madison
Partners
Hassan Boukcim and Estelle Hederi - Valorhiz
Gaghik Hovannissian and Marc Lointier - IRD

Table of Contents
I. TypoSoil® System ................................................................................................................................................. 1
1. Process Overview and Purpose ....................................................................................................................... 1
2. Main System Components .............................................................................................................................. 1
3. Warnings/Cautions ......................................................................................................................................... 2
II. Soil Samples ....................................................................................................................................................... 3
1. Field Core Sampling Procedure ....................................................................................................................... 3
2. Reconstitution of Cores .................................................................................................................................. 4
3. Wetting Sand Box /Saturation of Soil Samples TYPOSOIL ................................................................................. 6
III. Preparation of Experimental Run ....................................................................................................................... 7
1. Degassed Water Preparation .......................................................................................................................... 7
2. SD Card Formatting ........................................................................................................................................ 8
3. Procedure for Ceramic Needle Preparation ..................................................................................................... 8
4. Preparation of the Support Platforms ............................................................................................................. 9
IV. Procedure for Measurement Cycle................................................................................................................... 12
1. Example Log Sheet ....................................................................................................................................... 12
2. Creating New File for TYPOSOIL .................................................................................................................... 13
3. Tare Balance ................................................................................................................................................. 14
4. Beginning Cycle ............................................................................................................................................ 14
5. Finishing Cycle .............................................................................................................................................. 16
V. Monitoring and Post Processing of Samples ...................................................................................................... 16
1. Viewing/Downloading of Data ...................................................................................................................... 16
A. Connecting the PLC to the Computer ........................................................................................................ 16
B. SD Card Explorer ...................................................................................................................................... 18
C. TYPOSync ................................................................................................................................................. 18
D. Direct Download of Data .......................................................................................................................... 19
2. Structural Mass Determination and Ceramic Needle Removal ....................................................................... 20
3. Cleaning of the Support Platforms ................................................................................................................ 21
VI. Results ............................................................................................................................................................ 21
Appendix ................................................................................................................................................................. i
1. Calibration....................................................................................................................................................... i
A. Laser Calibration ........................................................................................................................................ i
B. Calibration Results ..................................................................................................................................... ii
2. Common Problems and Troubleshooting ....................................................................................................... vi
3. French Word Translations .............................................................................................................................. ix

1
I. TypoSoil® System
1. Process Overview and Purpose
The TypoSoil ®is a device intended to simultaneously measure both the shrinkage and water
potential curves of a soil sample. The soil shrinkage curve measures the soil specific volume with
reference to the reference to the gravimetric water content. The water retention curve also known as
the soil water characteristic curve is also measured in reference to gravimetric water content. These two
curves as well as the swelling and conductivity curves are necessary to define the hydrostructural
behavior of soil based on the SREV (Structural Representative Elementary Volume) concept developed
by Braudeau and Mohtar (2009). The methodology of measurement is simply the implementation of a
tensiometer into the support plates of the retractometer of Braudeau et al 1999.
TypoSoil® is able to generate the shrinkage and potential curves by measurement of water
retention, diameter, height and weight of the soil core during a drying cycle starting from saturation.
Drying cycles occur at fixed temperature. 8 samples can be measured each cycle. For each sample a set
of measurements is taken approximately every 12 minutes. The water retention is determined with a
ceramic-needle tensiometer in the approximate functional range of 0-850hPa. The height and diameter
of the soil core are measured by a set of lasers. The diameter is measured by a thru-beam displacement
laser, and the height is measured by a spot displacement laser. The sensitivities for diameter and height
are 5μm and 10μm respectively. The gravimetric water content is measured by the change in weight of
the soil core as it is lowered on to the scale each turn. The dry weight of the core is used afterwards to
determine the water content.
The measurement of these state variables and their translation into the two soil moisture
characteristic curves: the shrinkage curve and the water retention curve, is the overall purpose of the
Typosoil®. These curves then can be defined by parameters in a curve fitting process. The parameters
are used in physical soil-water models to quantitatively describe the hydro-structural functionality of
the soil medium.
This manual will give detailed account of the measurement cycle from soil sampling to post
processing after a TypoSoil® cycle, including: core construction, preparation and running a cycle, data
collection, calibration, and troubleshooting
common problems.
2. Main System Components
The picture at the left displays the
system components of the TYPOSOIL system
without the implemented tensiometer that is
housed inside an oven. The tensiometer ceramic
needle is inserted into the soil sample and

2
attached to the pressure transducer within the support plate. The turning plate can house 8 support
platforms on the turning plate.
The spot laser is a KEYENCE IL-Series CMOS Multi-fuction Analog Laser Sensor. The Thru-beam laser is
KEYENCE IB-Series Laser Thrubeam Sensor. The balance is Mettler Toledo NewClassic MS scale.
ref capteur pression
3. Warnings/Cautions
Boiling Water: Water is boiled for the preparation of degassed water. This hot water could pose a burn
threat if not handled properly, especially when screwing on the cap to the glass bottles. A hot pad is
recommended.
Ceramic Needle Tensiometers: Do not touch the ceramic part of tensiometers. The grease, sweat or
soap residues can affect the hydrophilic performance of the ceramic. The ceramic needles are very
fragile always be careful handling them. Do not remove from soil sample without first wetting the soil
core.
Pressure Transducers: Be careful when degassing and preparing support platforms for the TYPOSOIL.
Sudden or large changes in pressure may damage the transducer. Always work slowly and avoid
situations with positive pressure within the support platform system.
SD Card Removal: Do not remove the SD card before activating the switch on the CYCLE screen for doing
so. Removing it before activating switch will cause problems on the next cycle with writing data to the
card which must be formatted in Unitronics format.
Turning Plate: Be sure to rotate the turning plate holding the support platforms only when in the up
position and only in a slow clockwise manner. Also, be sure none of the tubes extending from the
support platform can catch on the internal components of the machine while rotating before beginning
any cycle.

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II. Soil Samples
1. Field Core Sampling Procedure
1) To prevent swelling once a core is taken, first saturate the ground with water so that the soil is
well saturated. (Take care not disturbed the soil surface when adding water) If the soil is very
dry to begin with, an infiltrometer will work well to saturate the soil by creating a hydraulic
head. Shown below is a crude inflitrometer used for ponding water.
2) Make sure the soil is saturated to the sampling ring depth and then it can be sampled using a
metal sampling rings (or PVC). Use the pounding point with the hammer to make sure that the
sampling ring goes straight into the soil, not at an angle. (Make sure not to compact the soil by
going beyond the soil surface). Multiple rings can be embedded in the soil within the same area
or replicate analysis.

4
3) Once all sampling rings are made flush with the soil surface remove the soil surrounding the
rings and then carefully level of the bottom of soil sample to be flush with the sampling ring.
Place end caps on the sampling rings to transport to laboratory. Make mark on sampling ring to
remember the orientation top/bottom of the core.
4) If also collecting soil for reconstituted cores, be sure to collect from the horizon/layer of interest
and to label appropriately.
2. Reconstitution of Cores
Procedure for Reconstituting Soil Cores “Disturbed
Cores”
1) Soil must be collected from the field and
dried in the oven for at least 24 hours at 40C.
This time may vary depending on the
moisture content at the time of sampling. The
purpose of drying the soil is purely to prevent
sticking of soil to the sieves during sieving.
The soil should be air dry before sieving.

5
2) The soil should be sieved for 10 min for anything less than 2mm also being careful to remove
any non-soil particles such as stones or roots. The soil can be gently crushed using a mortar and
pestle if the aggregates are too large after drying. It is important not to pulverize the material
but rather to gently disaggregate by crushing. The soil can be further sieved into desired sizes
based on the soil.
3) Cover the inside surface of the sampling rings with a very thing coat of petroleum jelly. This will
prevent the soil core adhering to the walls during construction.
4) Place filter paper on saturating dish or pan. Wet the filter paper, removing any trapped air
bubbles. Place and center sampling ring on middle of filter paper. If more than one type of core
is to being constructed, label sampling rings and keep record the soil types/aggregate sizes.
5) Add small amounts of soil
aggregates, keeping a level
surface of soil within the ring.
Do not pack or tamp the soil.
Tapping the edge of the ring
to settle the soil material is
recommended. Do not add
too much soil at one time by
waiting until the soil becomes
wetted before making
another addition. Too much
soil addition at one time will
cause poorly formed cores
and/or segmentation. Also,
occasionally add water to the
outside of the ring to wet the soil by capillary action. Do not allow the filter paper to become
unsaturated. Always keep a short depth of water (< 5 mm) in the saturating dish or pan.
6) When the sampling ring is near full of soil be extra cautious to keep a level surface. A straight
edge is often useful in leveling the very top, when still dry. When the ring is full, and the
reconstituted core is saturated, the soil then needs to go through a period of drying and wetting
to reconstitute the soil matrix structure.
7) Remove any excess water from the outside the sampling ring(s) and place in an oven set at 40C
for about 48 hours. The time required for drying will vary depending on the soil type, salinity
and other factors. The goal is not to over-dry the soil. Shrinkage should occur to the end of the
basic shrinkage phase, but before the residual water is removed from the soil structure.
8) After the sample is dry, saturate again with capillary action by adding water to the outside of the
ring while in the saturating dish or pan. Again, keep water supplied as to avoid drying out the
filter paper. The sample is saturated when the top is wet to the touch and looks slightly glossy.
9) Repeat step 7.
10) After the soil has been dried for the second time it is ready to characterized using the TYPOSOIL.
11) If constructing many reconstituted cores at the same time it is helpful to keep track of the cores
using a core construction log like the example shown below.

6
3. Wetting Sand Box /Saturation of Soil Samples TYPOSOIL
After reconstitution or taking cores from the field they need to be saturated before beginning
the TYPOSOIL cycle. The wetting sand box is a method for saturating cores by capillary movement of
water. The cores will be placed on top of the wetting sand box and allowed to saturate before being
measured in the TYPOSOIL.
Wetting Sand Box Preparation: Place the wetting sand box cylinder in a large beaker with the netting
side down to help keep sand held in the cylinder. The wetting sand box cylinder should be filled with
sand and water should be added to the beaker around the wetting sand box. The sand should be leveled
with top of the cylindrical wetting sand box. The water level should reach 2-10 centimeters below the
Soil Type/ Aggregate Size Sample Ring ID
Constructed
Date/Time
First Oven Drying
Began Date/Time
Resat Date/Time
2nd Oven Drying
Date/Time
Notes
Core Construction Log

7
top of the wetting sand box to provide adequate saturation depending on the application. A looking
glass should be placed on top of the beaker to minimize evaporation.
Saturation: Cover the sandboxes with filter paper and then place the
dry soil cores on top to prevent direct contact with the sand. Allow
the soil core to saturate on top of the sandbox for at least 24 hours. If
the soil core was placed on the sandbox with the ring still on it, the
ring should be removed when it is possible. It is acceptable to
saturate the soil while still in the ring because the soil sample was
saturated during reconstitution/field sampling. The ring therefore
should not prevent any swelling of the reconstituted soil cores.
However, the ring may stick to the more deformable, saturated soil
sample. This could damage the core and so it is better to remove it
within the first few hours of saturation. Field samples should be
removed from the ring prior to saturating on the sandbox unless,
they were extracted from fully saturated soil. Keep the water level in the sandbox at 2-10 centimeters
below the top of the sandbox during saturation, with the height depending on the level of suction
required. Place the looking glass on top of the beaker to keep the evaporation to a minimum.
After Saturation: When the core is saturated, (approximately 24 hours) it can be carefully removed and
placed on top of a prepared support platform. Slightly wetted gloves are recommended to minimize the
sticking of soil particles to the hands during the movement of the core to the support platform.
III. Preparation of Experimental Run
The following items for preparation of an experimental cycle should be completed in advance of
starting a TYPOSOIL cycle. Following the procedures ahead of time will ensure quality measurements
and prevent wasted time in starting a cycle.
1. Degassed Water Preparation
Degassed water is necessary for the preparation of the ceramic tensiometers and the support
platforms. Removal of gas is essential for proper measurement of the matric potential. Air entry will
inhibit measurement.
Warning: Water is boiled for the preparation of degassed water. This hot water could pose a burn threat
if not handled properly, especially when screwing on the cap to the glass bottles. A hot pad is
recommended.

8
Deionized or distilled water should be used for degassed water to minimize effects of osmotic
potentials in measurement. The water needs to be brought to a rapid boil. Allow the water to over boil
for 10 minutes. Remove from heat and immediately pour the water into glass bottles to the very top.
Screw on the cap very tightly to form air tight seal. Allow this water to cool to room temperature before
use. This is best prepared the day before a desired TYPOSOIL run.
2. SD Card Formatting
Formatting the SD card is recommended every time you start a new experiment to avoid
possible data recording issues.
To format the SD card:
From the main screen select CYCLE >> Turn RETRAIT CARTE SD knob to ON.
Once the light changes to green, the SD card can now be removed safetly from
the PLC. Make sure the card is unlocked with the switch up and insert it into the
appropriate slot on a computer with SD Card Suite installed.
Open SD Card Suite>> Tools>> SD Card Format Tab>> Fill in or Select Card
Info>>Click Start button (it may take 10-20 minutes to format the SD Card.)
Safetly remove the SD card from the computer after formatting is complete. Re-insert the SD card in its
correct slot before beginning any TYPOSOIL set-up.
3. Procedure for Ceramic Needle Preparation
Degassed water should have been prepared several hours or a day before by boiling deionized
or distilled water for 10 minutes, placing in temperature safe containers immediately afterwards and
then allowing to cool to room temperature in a closed container.

9
At least 48 hours before the desired test the ceramic needles
must be placed in degassed water to saturate them. (Note: Whenever
possible, handle with forceps and never touch the ceramic needle with
your hands to prevent natural grease from damaging the ceramic.)
On the day of test, check the ceramic needles by using suction and
positive pressure while they are submerged in degassed water to
make sure the ceramic has no air bubbles and to check for leaks. This
is best accomplished by creating a vacuum with the syringe with
fixable, or lockable, plunger. Attach the ceramic needle that has been
saturating for 48 hours, to the syringe with fixable plunger. Place the
ceramic needle in degassed water and pull back the plunger and lock
in place. This will create the suction necessary and should pull water
into the syringe shaft and remove any remaining air
bubbles. When the plunger is pulled back and fixed, it
should not have a large number of air bubbles. Allow
the 20mL syringe to filled to make sure the ceramic is
degassed. If bubbles are minimal then apply positive
pressure (remembering not to push air into the
ceramic needle) to release water from the ceramic
tip. Push hard enough to expel water, but not so hard
as to create high pressure that may cause the
ceramic tip to break or pop off the tubing. It should
form small drops and be difficult to force out. If it
comes out in a stream the ceramic needle is broken and cannot be used.
4. Preparation of the Support Platforms
The soil support platforms must be prepared in the proper way to ensure accurate matric
potential measurements. Air bubbles must not be present in the systems. Collect the following
materials: 8 support platforms, 8 small red tubing stoppers, syringe with nipple connector, syringe with
needle tip, 8 ceramic needles (keep in degassed water until used), plastic tubing, plenty of degassed
water, small beakers.

10
1) Attach a short section of plastic tubing (approx. 2cm) to the side of the support platform with a
black dot and a number on it. Add a longer section of plastic tubing (approx. 8 cm) to the other side.
If the longer section is too long it may not allow proper rotation of the samples by catching on
internal components during TYPOSOL operation.
2) Fill the syringe with the nipple connector about full of degassed water. Bring the water into the
syringe slowly as not to reintroduce gas into the degassed water. Then attach this syringe with
nipple connector to the short end and place the other, longer end in a small beaker filled with water
(enough water to keep the end of the tubing below the surface of the water)
3) Slowly, as not to damage the membrane inside the support platform, push the water from the
syringe through the platform to the beaker and then use suction, again slowly, to pull the water
back into the syringe. This should expel the air from inside the support platform. Do this until after 3
cycles, of pushing and pulling back the syringe plunger, no air bubbles are manifested from the
support platform. Be careful not to completely withdraw all water from beaker or to completely
expel all water from the syringe as this will reintroduce air bubbles into the system.

11
4) Once the system is free of air, create a small rounded surface of degassed water extending from the
longer tube orifice by pushing water through the system with the attached syringe with nipple
connector. Then attach the ceramic needles to the longer tubing side making sure no air bubbles are
trapped within the tubing. After the ceramic needle is attached, immediately place it in a beaker
with degassed water to keep it saturated until it is used in the tare balance.
5) Then the syringe with tubing connector can be removed from the short side and the needle syringe
can be used to make the same rounded surface of degassed water before you insert the small red
plug, again making sure no air bubble within the tubing. Insert the red plug very slowly to prevent
pressure build up and damage to the transducer. The red plug will be removed during the tare
balance and replaced immediately after with the same procedure to prevent intrusion of air
bubbles.
6) Once all support platforms are prepared, tape the ceramic needle side, (above the ceramic because
the adhesives could ruin the ceramic needle), remove the red plug and place the small spot square
as well as the red plug on the support platforms before placing them in TYPOSOIL for tare balance.
Preform the tare balance quickly, so that the ceramic does not dry out. (Tare balance is outlined in
the procedures for setting up a measurement cycle.)
7) Once the tare balance is completed the ceramic needles should be again placed back into small
beakers filled with degassed water and red plugs should be replaced following the procedure with
the needle syringe to ensure not air bubbles as outlined
above.

12
8) When you are ready to begin an experiment, place the soil core in the exact center of the support
platform and then place the ceramic needle into the middle of the core until the ceramic part is
completely inside. Then replace the small spot square on top of the sample with number side down.
The samples are now ready to be placed back into the Typosoil.
IV. Procedure for Measurement Cycle
Once all the preparations for a cycle are complete, the procedure for beginning a cycle can
begin. All steps are important and missing any can cause data to be recorded incorrectly or not at all.
Log sheets and always following these steps will minimize mishaps.
1. Example Log Sheet
When running a complete TYPOSOIL cycle, with preparation from beginning to end, it helpful to
have a log sheet to prevent mistakes and to record notes on the experimental run. Below is an example
of a log sheet that can be used to record pertinent data to ensure all the no steps are missed.
Time
Checklist 1 2 3 4 5 6 7 8
Core Description/
"Enchillion"
Tare Weights (g)
Tension Measure (pts)
Photo Numbers
Centered for Spot
Data Being Collected
Centered for Barr.
Dish Code and Mass
Mass Dish + Sample 105C
Mass Sample 105C
pH
EC [mS/cm]
Comments
Typosoil Log and Checklist
Sample Number
Card Formatted?
Filename/"Nom du Lot":
Before:__________________ --__________________
After:__________________ --__________________
Operator
Samples Rotate w/o Tubes Catching?
Y / N
Wheel in Raised/Set Position Before Cycle
Y / N
Y / N

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2. Creating New File for TYPOSOIL
This section will cause the PLC to begin writing a new file on the SD card for saving the next run.
1) If not already on, switch on the TYPOSOIL using physical red knob on top left of machine front.
2) Warm up the oven to 40⁰C, it will take around 20 minutes. Turn on the oven using the ON/OFF
button if it is not already on. Warm up oven by pressing the
modify set point button on the front of the oven door and
then selecting the temperature by choosing the up and
down arrow and then pressing the modify set point button
again. It is best to have the oven on for hours before the
intended cycle. This acclimates the instruments and
prevents error due to temperature drift.
3) Make sure SD card is formatted as per the instructions in
Format the SD Card section and in its correct slot.
4) Check that the balance is working.
5) You can go from the MAIN TYPOSOIL SCREEN, select
MANU>>ROTATION>>Turn Knob (ON) so that you can place
the support plates in proper alignment before beginning the
cycle or test cycle. Be sure not to rotate the turning plate
while in the descended position.
6) Using support platform, check that the spot laser is in the direct center of the support plate when it
lowered on the balance.
7) From main screen, go to SAISIE >> Fill in the “Nom du fichiers” and “Nom du lot” or sample names
>> Next button >> Fill in your name for "Operateur" or operator and on each “Enchantillion” fill the
description for each sample >> Fill in "Commentaires" or comments for each sample. >> Next button
>> To open a new file for recording data turn ON the knob and press the GREEN BUTTON under RAZ
CYCLE. Turn off the knob after pressing the GREEN BUTTON. Press RETOUR to go back to main
TYPOSOIL SCREEN.

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3. Tare Balance
The following steps are for the tare balance or having the initial mass of the support plates zeroed.
Complete the tasks quickly and carefully to minimize the time the ceramic is exposed to drying. This task
is completed after creating a new file on the SD card for the data to be stored.
1) Place the prepared support plates on their proper sites (make sure that the plates are placed
properly and fixed in place on the small notches and with the ceramic needle side toward the
center.) The number order of the support plates is very
important!!! Also, make sure that the rotating wheel
that holds the platforms is in the raised position and is
rotated to the center of a sample before beginning. Be
sure the ceramic is taped and the red plug removed
during the process.
2) To record the initial weight of the support platforms
and the initial tension measurements with the
attached ceramic needle and spot square, go to ETAL.
>> BALANCE >> Turn knob (ON) >> Return to main
screen
3) Go to TEST >> TURN KNOB ON >> Return to main screen to being a test cycle which will go through a
normal cycle without recording data to the SD card. Check that the wheel that hold the support
plates/platforms is in the raised position and rotated to a sample or else the wheel may descend
without rotating to the next sample.
4) Go to DONNEES and record by hand the mass and tension (atmospheric pressure in this case)
measurement for each support platform as the test cycle proceeds. Alternatively, the tension
5) Return to main screen then ETAL. >> BALANCE and make sure the weights have all been recorded.
Turn knob (OFF) on the ETAL. DE LA BALANCE Screen to stop recording the weights of the support
plates. Then return to main screen and go to TEST >> Turn knob (OFF) to stop the test cycle.
6) Remove the support plates from the TYPOSOIL and place the ceramic needles back in degassed
water until they are inserted into soil cores for the cycle.
4. Beginning Cycle
1) After the new file is created and tare balance is
completed, remove the support plates from the TYPOSOIL
and place the ceramic needles back in degassed water.
Then place each soil core from the sandboxes onto the
respective support plate base and insert the ceramics
needles into the middle of the cores. Then return the
support plates with cores back to the TYPOSOIL with
proper placement.

15
2) Rotate the wheel around one time to make sure no tubing catches on internal components of the
TYPOSOIL.
3) Position the rotating wheel to the raised position and after align with any sample before beginning a
cycle. From the main screen, CYCLE >> CYCLE knob (ON).
4) During the first rotation of the cycle, go to the DONNEES screen. Monitor the instantaneous data
being collected to ensure the cycle is proceeding correctly. Specifically, make sure the squares for
reflecting the spot laser are centered with the laser. If not they can be adjusted on top of the cores.
Also, make sure that the BARRAGE 1 and BARRAGE 2 values are at least 100 PTS and fairly equal. If
the values are very different, it suggests that the
soil core was not placed in the center of the
support platform, which could affect
measurements. If the cores need to be adjusted,
pause and then continue the cycle by turning the
knob to OFF, making the adjustment, and then
turning back ON the cycle knob.
5) To ensure the PLC is writing the measurements to
the SD card, set up a connection with the PLC
through Ethernet cable. Through SD card Explorer
you can check and download data has been saved
to the SD card while the cycle is in progress. (See Connecting PLC to Computer-Ethernet Connection
and SD card Explorer sections in Viewing/Downloading of Data)
6) During operation of the cycle the histograms of the measurements can be displayed for each sample
or “poste” by selecting HISTO followed by the sample you select. Once a sample is selected, the
histograms can be adjusted by selecting the number of data points to show a different graph for the
several measurements taken of each core.
7) The TYPOSOIL will operate continuously until the user determines the end of the cycle
(approximately 2-4 days) and manually stops the TYPOSOIL.

16
5. Finishing Cycle
Note: The TYPOSOIL cycles usually take 2-4 days depending on the soil. Once the tension curve
“breaks” the matric potential is no longer being collected. This “break” corresponds to the air entry
point into the ceramic tensiometer. It is necessary to keep the cycle running until the size of each
sample no longer changes to determine the full shrinkage curve.
1) Using the graphs from the HISTO menu or using SD Card Explorer determine when the size of every
core is no longer changing.
2) At This point turn the knob for FIN CYCLE to “ON” on the CYCLE Screen. Each support plate will take
one more measurement before ending the cycle.
3) When the FIN CYCLE completes, both the CYCLE and FIN CYCLE knobs will automatically turn to
“OFF”. The TYPOSOIL completes the cycle with the rotating wheel in the down position. Use the
MANU screen to bring the rotating wheel to the raised position. At this point the samples may be
carefully removed.
4) The Samples will then need to be post processed and the data downloaded. See separate section for
these procedures.
V. Monitoring and Post Processing of Samples
The following sections will aid in finalizing the measurement cycle for a set of soil cores. It will
also explain how to view data and manage data on your computer though ether-net connection. Finally,
this section will describe proper cleaning for a next cycle.
1. Viewing/Downloading of Data
There are multiple ways to download and view data with the TYPOSOIL. It is good to use one of
these methods to check that data is being recording throughout the cycle. Data can be downloaded to a
computer for use in excel in three ways. The measurements can be downloaded after a connection is
made through Ethernet cable using TYPOSync or Data Explorer. Also, a direct download from the SD card
is possible after a completed cycle.
A. Connecting the PLC to the Computer
1) Connect the computer to the TYPOSOIL-PLC via Ethernet cable.
2) Open “Network and Sharing Center” in the Control Panel or open it by clicking on the internet icon
shown in the lower right hand corner.

17
3) Then go to Local Area Connection. If you are not connected to the internet it should be your only
available connection.
or
4) From the Local Area Connection Status window, click Properties. Then select Internet Protocol
Version 4 from the list and select Properties. In this window, select Use the Following IP Address.
Type in the IP address given For the TYPOSOIL, but with a 2 for last number instead of 1. The Subnet
Mask is 255-255-255-0 by default. The Default Gateway is the IP address given. Then click OK, and
close out the windows.
5) After forming this connection, data can be viewed and/or downloaded with TYPOSync or SD Card
Explorer.

18
B. SD Card Explorer
SD Card Explorer is valuable for browsing and downloading data from the SD card while it is inserted
in the PLC of the TYPOSOIL. This can be very useful to view files mid-cycle to check that measurements
are being recorded and to check potential or shrinkage curve progression.
1) Make sure SD Card Suite is installed on
computer.
2) Complete the Ethernet connection (as
described in “Connecting PLC to Computer”).
3) If this is the first time using SD Card Explorer,
click on the Settings Icon to open the
Communication Settings window. Fill in the
Communication Parameters as shown in the
picture. Click “Check Connection” to make
sure the connection is
established with the PLC and
then click OK to exit the
window. The settings should
be saved for the future. Skip
this step if not necessary.
4) Click Open to view the
folders/files on the SD Card remotely.
5) All files for the TYPOSOIL will be saved in the
EXCEL>>EXCEL 1 folder. The CSV files will be simply
downloaded as the sample number. Double-click
on any file to open and view it.
6) Use the green and orange arrows button to refresh
the data to obtain the most current
measurements. Use the two down arrows to
download selected file(s) to the computer, and use
the black box with green arrow to download the
whole SD card.
C. TYPOSync
The TYPOSync connection is used to download data from the SD Card while still inserted in the PLC
of the TYPOSOIL.
1) Make sure the latest version of TYPOSync is installed on computer. This should also create a folder
on the Desktop called TyposoilData.
2) Complete the Ethernet connection (as described in “Connecting PLC to Computer”).

19
3) Open the TYPOSync and go to the Configuration Tab. make sure that the Addresse IP is as shown in
the picture. If he IP Address does not match change it to match the picture.
4) Click Connection button in the Download Current Samples tab. When the lower left corner says
Connecté, you connected and ready to download.
5) Select Download and the files will be downloaded to a folder within the TyposoilData folder on the
Desktop. The .csv files will be given a name based on the date and sample number. These files will
be placed in a folder with the same title as “Nom du Lot” that is created at the beginning of the
cycle.
D. Direct Download of Data
Direct download of data files is a method that can only be used after completing a cycle.
1) After the cycle is completed (including the FIN CYCLE
portion) Remove SD card. Do not remove the SD card
before activating the “RETRAIT CARTE SD” switch on the
CYCLE screen. Removing it before activating the switch will
cause problems with writing data to the card on the next
cycle.
2) After safely removing the SD Card, it can be opened on the
computer. Copy or cut files as necessary to the proper
folders.

20
3) After files are saved to a secure location, it is recommended to format the SD card for the next use
since it takes time.
2. Structural Mass Determination and Ceramic Needle Removal
The structural mass is the mass of just the solid portion (soil skeleton) of a soil core. In order to
calculate the gravimetric water content (dry basis), specific volume of the soil, and many of the other
hydro structural parameters, the structural mass must be determined.
1) Take the weight of an oven safe dish for each soil core to be post processed. Make sure each dish is
labeled to distinguish the samples. Record the mass of each dish with its code/label.
2) During the TYPOSOIL cycle the soil cores will shrink and become firmer as soil water evaporates. The
soil structure will close around the ceramic needle. In order to reuse the ceramic needles, they need
to be removed carefully. Place the soil core, with ceramic needle still inside, on its side in the dish.
Scrape any soil particles sticking to the platform into the dish.
3) Using the syringe with needle tip, gently rinse the support platform. Throughout the removal
process using only a little water is a best
practice and will reduce drying times.
4) Begin to saturate the soil core around
the point of attachment of the ceramic
needle. Using a small spatula gently
remove the wet and more soft soil
surrounding the ceramic needle. Repeat
saturating the soil core with small
amounts of water and excavating the soil
around the ceramic needle until it comes
free. Alternatively, water can be pushed
through the tensiometer by connecting a
syringe to the tubing. In both cases,
remember to keep all soil particles
within the weighing dish.
5) Scrape off any remaining soil on the tensiometer and rinse into the weighing dish.
6) Complete steps 2-5 for each soil core.
7) Place all soil cores in the oven at 105⁰C for at least 24 hours to remove all moisture.
8) Take the weight of the samples after drying and subtract the mass of each dish to determine the
structural mass.
9) This data should be recorded and kept with the data from the TYPOSOIL run such as the example log
sheet shown in the previous section.

21
3. Cleaning of the Support Platforms
Support Platforms should be cleaned after each use. This assures quality of the measurements and
keeps the support platforms in good working order.
1) With the tubing and red stopper still
attached, dip the top of the support
platforms in soap water. Hold the
support platforms upside down to
preventing any soapy water from
entering the tubing or bottom of the
platform. Be sure not to submerge the
support plate.
2) Gently scrub with brush or sponge to
remove all dirt and rinse. Again, be
sure not to submerge the support
plate.
3) If the support plate is very dirty it is
possible to remove the clear plastic
support plate to have more access to
cleaning.
4) The metallic bottom of the support
platforms that form a connection for recording measurements should be gently cleaned to provide
satisfactory contact with the connection points on top of the scale.
5) Allow the support platforms to dry completely before using again. Wet support platforms will dry
over a TYPOSOIL cycle and affect weight measurements.
VI. Results
Some fundamental studies could not be realized without the use of TypoSoil and several original
results were obtained on different kinds of soil in Qatar. Detailed can be seen in Braudeau et al. (2014a)
1
Assi et al. (2014)
2
, Braudeau et al. (2014b)
3
and Braudeau and Mohtar (2014)
4
1
Braudeau, E., Assi, A.T., Boukcim, H. & Mohtar, R.H. 2014a. Physics of the soil medium organization part1:
thermodynamic formulation of the pedostructure water retention and shrinkage curves. Front. Environ.
Sci. 2:4. doi: 10.3389/fenvs.2014.00004
2
Assi, A., Accola, J., Hovhannissian, G., Mohtar, R.H. & Braudeau, E. 2014. Physics of the soil medium organization
part2: pedostructure characterization through measurement and modeling of the soil moisture
characteristic curves. Front. Environ. Sci. 2:5. doi:10.3389/fenvs.2014.00005

22
Here after, the results of an experiment using the TypoSoil are given to show the excellent
quality of the data obtained in terms of accuracy and reproducibility of the method of measurement
demonstrated in this manual.
The goal of this specific experiment was to determine if the temperature has an impact on the
measurement of both curves, in particular the water retention curve. In actuality the measurements are
made at a constant temperature of 40 °C, judged as the maximum possible in regards to the electronic
sensor functionality (particularly the balance), and to keep a low enough evaporation rate as to maintain
a negligible gradient of the water content within the sample. The idea posed was to determine if the
results (V(W) and h(W)) would be the same at 25 °C where the evaporation rate of water from the
sample is much lower.
Three replicates of reconstituted Rodha soil sample, with aggregates sieved to less than 2mm,
are wetted and put in Typosoil for a measurement run according to the procedure defined above except
that the temperature is suddenly changed from 25 to 40 ° C and vice versa during the drying cycle.
The first figure here represents the directory where are stored the files of data coming from
TypoSoil along with the log-sheet file. Then, the following figures show the excel sheets corresponding
to each step of for the treatment of the data:
3
Braudeau E, Hovhannissian G, Assi AT and Mohtar RH (2014) Soil water thermodynamic to unify water retention
curve by pressure plates and tensiometer. Front. Earth Sci. 2:30. doi: 10.3389/feart.2014.00030
4
Braudeau, E. & Mohtar, R.H. 2014. A framework for soil-water modeling using the pedostructure and structural
representative elementary volume (SREV) concepts. Front. Environ. Sci. 2:24. doi:10.3389/fenvs.2014.00024

23
a) Data from Typosoil for one sample of measurement. The change of temperature is visible on the
evaporation curve (decrease of the sample mass with time) and on the other measurements shown with
time, in particular the water retention.
b) Calculation of both moisture characteristic curves, V(W) and h(W), from measured data

24
c) Fitting of each measured curve with its theoretical parametric curve
d) Details on the water retention curve results: W and h measured, the micro and macropore water
contents Wmi and Wma at equilibrium calculated for each W, and the theoretical corresponding water
retentions hmi (Wmi) and hma(Wma) in both pore systems (Braudeau et al., 2014a). The squared deviation
(hmi-h)2 (column Sdhmi) does not exceed a value of 10 for nearly all points over the range of validity of
the measurements (nbre points), the mean square deviation being in this case: 2.52.
Results clearly show that there is no influence of the change in temperature on the water retention
curve during the measurement process: parameters 
 
 
 and
 of the water
retention curve stay exactly the same all over the range of validity of the tensiometer measurement

25
(from h=0 at saturation to h= 850 hPa). We have the same result about the shrinkage curve in the range
studied here.
This result confirms the theory (Braudeau et al., 2014a,b) where we showed that, for each value of W,
the soil water retention pressure at equilibrium is:
        
On the other hand, the Gibbs-Duhem equation for the soil medium at equilibrium is written as:
  

  
  
where  and 

 are the pedostructure macroporal water entropy    and
macroporal water volume 

  
, and 
 is the macroporal water content (or interpedal
water content) 
    of the pedostructure sample of mass .
According to the Gibbs-Duhem equation, a little change in temperature at constant pressure (dP=0)
leads to a change in potential such as:   
 which is the same for the both quantities:  and
. This explains why h is not affected by a variation of temperature.

i
Appendix
The appendix will go over calibration of TypoSoil, examples as well as common problem’s and how to
resolve them.
1. Calibration
To maintain quality in measurements periodic calibration of the sensors between cycles is
recommended. Proper calibration is directly affects the measurement of samples. Care should be used
to select quality standards for calibration.
A. Laser Calibration
The lasers are calibrated with four standards or
“PIGES” in between cycles. The standards cylinders
of 52mm, 50mm, 48mm, and 46mm in both
diameter and height.
1) Place each standard on four consecutively
numbered support platforms. (Example: Place
them on 1-4 or 3-6) the order of the standards
does not matter. Also make sure to place a spot
square on top of each standard.
2) Queue the first standard to the descended position on the scale using both ROTATION and DECENTE
from the MANU screen.
3) Go to ETAL.>> LASERS to arrive at the “ETALONAGE DE LASERS” screen. Select the switch for the
standard in position to turn it “ON”. The switch will almost immediately turn itself off. (Example:
50mm standard is position. You select the PIGE 50mm switch to calibrate for that height and
diameter.)
4) Then select “PIGE SUIVANTE” to “ON” or next standard. This will automatically rotate the next
support platform with standard into the correct position.
5) Again, select the appropriate switch for the standard in the descended position.
6) To calibrate for each standard repeat steps 4-5 until all four standards have been used for
calibration
7) Return the rotating wheel to the raised position and remove the standards from the TYPOSOIL.

ii
B. Pressure Calibration
Pressure Calibration is done with the Keller low
pressure calibrator (LPX). With the vacuum pump
it can induce suction pressure 0.85 bars. When
the pressure is induced to a support platform you
can use the ETAL. screen to equivocate the
negative pressures to those listed varying from 0-
900mb of suction.
C. Calibration Results
A more intricate and precise calibration was completed in May of 2013 including: repositioning of
sensors into the critical range, signal transmission and voltage, and extensive testing. Report of the tests
and methods are described in the following.
Results of the laser sensors calibration
Using of the device "Typosoil" is expected to study the shrinkage curve characteristics of soil samples. To
follow the cylindrical samples volume variation related their water content, the diameter and the height
of each sample are regularly measured during the saturated samples desiccation. The temporal series of
these measurements and those of the weight allow obtain the shrinkage curves.
Two identical "Laser Thrubeam, IB-10" sensors are used for diameter measurements and one "CMOS
Multi-Function Analog Laser, IL-065" sensor for height measurements.
For accurate and stable measurements using laser sensors, it is required to meticulously adjust the
position of each sensor, and to carefully set the parameters of internal amplifiers, in order to obtain a
linear response in the measurement range of each system "sensor - amplifier".
After setting and calibrating of laser sensors, the sensitivities of height measurements is less than 10 µm
and less than 5 µm for diameter measurements.

iii
Below are presented the calibration curves of both laser sensors and corresponding linear regression
equations.

iv
Results of the pressure sensors calibration
Tensiometric or water retention potential measurements are performed using pressure sensors "SSI
SENSORTECHNICS". Each sample holder is provided with a sensor of this type. For equipment "Typosoil"
the calibration is performed on all the eight sensors.
Calibration procedure allowed us to detect leaks in the hydraulic system of the sample holder # 2.
It should be noted that the features of all seven calibrated sensors are very close and all are
characterized by linearity in the measurement range: from atmospheric pressure until depression of -
900 mbar (see Results).

v
During calibration of pressure sensors, we observed changes in atmospheric pressure up to 5 mbar for a
period of 4 hours. In order to improve the measurements accuracy and avoid the influence of variations
in atmospheric pressure, it is recommended to add another identical sensor in the oven to monitor
these changes. Monitoring of air pressure changes will enable to make appropriate corrections to the
acquired data.
We also discussed the possibility of adding two additional channels for very accurate measurements of
the temperature in the sample volume and close to the evaporation surface.
2. Tensiometer Construction and Repair
The ceramic needle tensiometers can be ordered from SDEC France (http://www.sdec-france.com) with
or without connecting tubing. If they are ordered without connective nylon tubing the connections will
need to be made prior to use with the TypoSoil. If ordered without tubing, the needles received should
be 2 cm in length, 2.1mm outer diameter, and 0.9mm as shown in the figure below.

vi
Nylon tubing (OD 3mm; ID 1.5mm) should first be cut to a length of approximately 1.75cm. The ceramic
needle will be pushed approximately 3mm into the tubing (hole end towards tubing). The fit should be
tight. However, if the ceramic cannot be inserted, the mouth of the nylon tubing can be widened using a
small metal tool before insertion of the ceramic needle. The point of contact with the ceramic and
tubing should then be glued with waterproof adhesive. Gel type glues work best as they will not
infiltrate the pores of the ceramic. After the glue is dried on the connection point, apply a thin layer of
glue to the tip of the ceramic needle. This is done because some ceramic needles we received, were
made with the ceramic too thin or open around the tip causing improper readings. If a small portion of
the tip is covered with glue the rest of the ceramic will function properly. This same procedure is used in
the event the ceramic breaks and the tubing can be reused, once it is clean. A finished ceramic needle
connected to tubing is shown below.
3. Common Problems and Troubleshooting
Many problems when not in the middle of measurement cycle can be solved by physically restarting the
TYPOSOIL by using the physical red knob on the outside of the machine. If this is does not solve the
specific problem see common problems below. Some of the most common issues possible with running

vii
a TYPOSOIL cycle are advised on in the following pages. Always adhering to the preceding procedure
sections will avert most issues.
The balance is not working:
Try restarting the balance, the TYPOSOIL and/or restart the scale by removing the power cable (from the
balance only). This will fix most issues.
The cycle not starting when CYCLE knob is turned to “ON”:
Make sure the RAZ CYCLE knob is turned to “OFF”, check that Tare Balance is completed, and that
rotating wheel is in the upright and set position. If the cycle does still not begin, try rotating to the next
sample and switching the CYCLE knob on again.
Tensiometer measurements intermittently or always recording zero pressure:
If the measurements are always recording zero there is likely a leak in the tensiometer systems allowing
air entry. If the cycle proceeds with intermittent zero values for soil matric potential, it is likely the
connection of the support platform to the three connection points on the balance is not forming a
complete connection. In this case clean the bottom of the support platform of any buildup. Also, slightly
adjusting the position of scale to have a tad different connection points to the support platform can
solve the issue.
Once cycle begins it freezes on support platform in descended position:
There is most likely a connection problems. Make sure that the small bolt in the rotating wheel is making
a connection with the electrical prongs underneath. If the bolt is not connecting the circuit the cycle will
not proceed. This can fixed by returning the wheel to the upright position and adjusting the respective

viii
Typosoil new1.vlp
bolt so it extends farther to depress the prong. This is also why the wheel should never be rotated while
in the down position. A bolt could wreck or break the electrical prongs off.
All data is not recording to SD card for one or more samples:
Follow these directions when TYPOSOIL does not write data to the SD card for any/all samples. Number
6 is given as the example in the subsequent steps, but can be translated to any sample that is not
recording. Alternatively, if access to Visilogic is unavailable, contact your supplier for technical support
on this issue.
1) Make sure SD card has correctly formatted, removed and replaced.
2) Connect PLC to computer using female 9-pin to RJ-11 cable. Connect to computer’s male 9-pin and
to Port 1 of PLC, respectively.
3) Open VisiLogic file Typosoilnew1.vlp in QEERI Folder >> VisiLogic Folder >>
4) Check that the connection is online by clicking the button on the toolbar.
5) Then expand Main Module and open Carte SD 6 in the menu list on
the left side of the window.
6) There will be three important numbers per file to check. Each
sample will be different, but the numbers can be determined by
those labeled “MB ___ Success bit:” highlighted by the green circle
in the position shown, where the blank is a three digit number. For
sample 6, these numbers will be 203, 205, 207. Then you must check that both the boxes
highlighted by green squares have the lines below them in red as shown. If they are black, click on
them and a window will open to “SET” or “RESET” them. Again, each “Carte SD” file will have three

ix
success bit numbers like 203. Do the same for 205 and 207 in “Carte SD 6”. Repeat the check for the
other two numbers as the first. If you want to double check, look at other correct Carte SD files that
are recording data and compare that the script is set the same.
4. French Word Translations
French
English
Acquisition
Acquisition
Arrêt
Stop
Barrière
Barrier
Commande
Control, Order
Commentaires
Comments
Cycle
Cycle
Descente
Decent, Going Down
Données
Data
Échantillon
Sample
Etal., étalonnage
Calibration

x
Fin
End
Heure
Time, Hour
Histo. Historique
Historic
Manu., Manuel
Manual
Masse
Mass
Mode
Mode, Manner
Montée
Rise, Ascent
Nom du fichier
File Name
Nom du lot
Batch Name
Numéro
Number
Operateur
Operator
Pige
Rod, Gauge - Standard
Plateau
Tray, Pan (Known as Rotating Wheel)
Poste
Position
Raz
(Used to Create New File)
Rotation
Rotation
Saisie
Entering
Selection
Selection
Spot
Spot
Suivant
Next
Temps
Time
Tensiomètre
Tensiometer
Test
Test
Validation
validation
Retour
Return

xi
5. References
Assi, A., Accola, J., Hovhannissian, G., Mohtar, R.H. & Braudeau, E. (2014). Physics of the soil medium
organization part2: pedostructure characterization through measurement and modeling of the
soil moisture characteristic curves. Front. Environ. Sci. 2:5. doi:10.3389/fenvs.2014.00005
Bellier, G., and E. Braudeau (2013), Device for measurement coupled with water parameters of soil. WO
2013/004927 A1, World Intellectual Property Organization, WIPO.
Braudeau, E. & Mohtar, R.H. (2014). A framework for soil-water modeling using the pedostructure and
structural representative elementary volume (SREV) concepts. Front. Environ. Sci. 2:24.
doi:10.3389/fenvs.2014.00024
Braudeau, E., Assi, A.T., Boukcim, H. & Mohtar, R.H. (2014a). Physics of the soil medium organization
part1: thermodynamic formulation of the pedostructure water retention and shrinkage curves.
Front. Environ. Sci. 2:4. doi: 10.3389/fenvs.2014.00004
Braudeau E, Hovhannissian G, Assi AT and Mohtar RH (2014b) Soil water thermodynamic to unify water
retention curve by pressure plates and tensiometer. Front. Earth Sci. 2:30. doi:
10.3389/feart.2014.00030
Braudeau, E., and R.H. Mohtar, (2009), Modeling the soil system: Bridging the gap between pedology
and soil-water physics, Global Planet. Change J., 67, 51-61, doi:
10.1016/j.gloplacha.2008.12.002.
Braudeau, E., M. Sene, and R.H. Mohtar (2005), Hydrostructural characteristics of two African tropical
soils, Eur. J. of Soil Sci., 56, 375–388, doi:10.1111/j.1365-2389.2004.00679.x.
Braudeau, E., J.P. Frangi, and R.H. Mothar (2004), Characterizing non-rigid dual porosity structured soil
medium using its shrinkage curve, Soil Sci. Soc. Am. J., 68, 359-370, doi:10.2136/sssaj2004.0359.
Braudeau, E., J.M. Costantini, G. Bellier, and H. Colleuille (1999), New device and method for soil
shrinkage curve measurement and characterization, Soil Sci. Soc. Am. J., 63, 525-535,
doi:10.2136/ sssaj1999.03615995006300030015x.
.