ISO - Science topic

Can anyone provide ASTM E1007-90? For measuring concrete thermal property ASTM E1007 or ISO 10534-2-90 can be used?

Hi, I want to do tensile analysis for my vulcanized rubber sample following the ASTM 412/ ISO 37. My starting rubber was ENR latex. As stated in that standard type 1, the standard thickness should be 2.0mm plus minus 0.2 mm. However, when I vulcanize the prepared sample around that thickness in drying oven, it resulted bubbles formed on the surface of the rubber film. this problem restricted me to proceed with tensile analysis as the sample will easily rupture for tensile and give me inaccuracy result. the problem is lessen when I reduce the thickness of the film to around 1.5mm. I am thinking to reduce the thickness, however, it will not following the standard thickness. Is it possible for me to do that with the above limitation? What is the condition/pre-requirement to reduce the thickness not following the standard (just for thickness part, other following the standard). I found some of papers that did tensile testing on vulcanized rubber sometimes not followed the standard thickness, but I do not know the reason behind that allowing to reduce thickness.

Any suggestion for me to solve this problem. Im really appreciate. Thank you.

I need to abbreviate journal title (in reference section) as per ISO 4 (Rules for the abbreviation of title words and titles of publications). Can anybody share ISO 4, please?

Hi there,

There is an internal gene in plant to diagnose of which ISO has a protocol, primer, and a temperature program. I have ordered this universal primer twice and checked annealing from 52-59. I just saw the same size non-specific band( far larger than the target) in both PC and NTC in each temperature 54-59. The results remain the same whatever I have changed, such as primer or DNA concentration, or master mix.

I am working on a security measurement framework for open source ERP software. I would like to get expert opinion on the factors that affect security attributes as defined in ISO/IEC 25010

In an attempt to modernise the security control framework, the new version of ISO 27002:2022 is out. I wondered if anyone had looked remarkably at the latest version to determine the level of modernising that might have been in implementation.

I’m interested in views of the new format and structure, whether it achieves its aims of modernising the security control framework to meet the challenges of modern architectures?

According to ISO 11930:2019(en) Cosmetics — Microbiology — Evaluation of the antimicrobial protection of a cosmetic product, the process to obtain a work culture is as follows: Attain a stock culture by unfreezing previously cryopreserved microorganisms; From this stock culture perform a subculture and incubate 18 to 24h; From the fist, subculture perform a second subculture and incubate.

The cryopreserved microorganisms are bought and therefore assumed to be pure cultures, so one would assume the sequential cultures aren't to isolate the pretended microorganism. Why according to ISO 11930:2019(en) can we only use the second and third cultures?

what is the form of citation of reference method ISO, AFRNOR in journal bibliography?

I need method for broth micro dilution assay for AST testing (ISO 20776-1:2019) It would be great if anyone could share a PDF Thanks :) ?

Hi,

I have tried several times to run WB with my protein lysate from heart tissue. My lysis buffer is 1XRIPA +1X of proteinase inhibitor and phosphatase inhibitor cocktails and the samples are always on ice. My samples buffer + adding reduced reagent as DTT before loading on the SDS 4-20% gel. I tried to detect my phosphorylated protein as phospho_phospholamban (Ser16), I got signals but the problem is I got also strong signal in my control samples (from sham mouse ) without any stimulation like ISO or other reagents. Sometime my control samples showing as strong signal as my stimulated samples therefore it is very hard to say the stimulated samples is actually stimulated or not. So I just wonder that do you have any idea why my control samples gave strong signal (band) even I added phosphatase inhibitor? Is it because low amount I did add ? Thanks for help!!

We have succeeded to etch only one Ni alloy, with Aqua regia.

I am reading ISO 19036 at point 7.2, which addresses counting uncertainty. For the calculation of the distributional standard uncertainty of a Poisson distribution is indicated the formula:

u_poisson = (1 / Ln10) / sqrt (EC),

being EC the number of counting colonies.

On the other hand, the variance of a Poisson distribution is equal to its mean value, therefore, the standard deviation should be its square root.

I understand that the units above correspond to a log10, but still the basic calculations give me very different values.

Can someone explain to me where the equation of the iso 19036 for u_poisson comes from?

I am trying to build ESP plot using fchk file and I get the following message 

Surface build !

Reading Cube File 

Writing Grid point

Line Number 64601

No data to plot.

Iso value may be out of Range.

Does anyone have any idea what this means and how to solve it?

Does anyone have an article in which the latest ISO guide 35 version has been used and can you send it to me? I need to review that rule urgently.

We have rated the lignin contents in the lignocellulosic materials using Kappa number (mL volume of 0.02 N potassium permanganate solution consumed per 1 gram dry mass of lignocellulosic materials under the specified conditions) according to ISO 302-2015. Could you recommend any other methods which perform more effectively or easily?

I am trying to develop a simple method for amateurs to make relative measurements of noise in digital cameras. One method involves taking multiple images of a standard grey card, bringing the images into Photoshop as a stack and then using Photoshop's standard deviation function. As expected, the mean value of the standard deviation over the image increases with ISO setting. However, there is also a distinct spatial pattern to the standard deviation visible at all ISO settings. (See example image attached.) Changing lenses or just adjusting focus changes the pattern. No corresponding pattern is observed when calcuting mean or median.

My experiments were conducted on a copy stand using a Canon 5D Mark II DSLR and a Kodak grey card. The attached image is the pattern when the card is in focus. The contrast has been enhanced to make the pattern clearer. The standard deviation was calculate from 10 images taken in rapid sequence under close to identical conditions.

Hi Everyone,

How can I download certain ISO documents (full version) for free? It would be helpful for my research.

I am after ISO 14040, 14044, 14067, and ISO 13065.

Thanks

I can't quite catch the meaning of the definition of "single stiffness ". In the case of helical gears, which plane does c' defined in, the normal plane or the transverse plane? It seems to be in the transverse plane from the definition.

In the equation (80), c’=c_th’C_MC_RC_Bcosβ. Why the fact for helical gears is cosβ?

c_th’ for helical gears is calculated in the normal section (per unit contact line). Should it be c_th’* cosβ/ cosβ= cth’ in the transverse section (per unit face width)?

Thank you for your time.

Dear Colleague,

Part of my Ph.D. thesis needs to be completed questionnaire, which, unfortunately, due to Covid 19, we cannot attend the company under review. For this reason, I request supply chain experts who wish to complete the questionnaire to notify me, that I will email the questionnaire to them. It would be your generosity to respond to the questionnaires and also distribute them among your colleagues, students, and networks.

Thank you in advance for your help and cooperation.

Hello,

Recently I've been looking for a strict guidelines considering the stability of chromatographic mobile phases. Found none, only some hints, good practice clues or SOP's from different labs all based on "scientific judgment". It is great for RnD, but not enough for GMP/ISO.

I bet many people here already dig this topic inside out. Can anyone direct me towards clear guidelines or possibly share the methods of testing the stability of the different mobile phases (besides pH checking) that she/he uses?

Any "hard facts" would be greatly appreciated especially for those working with routine and GMP analyses, and before audit :)

Cheers!

Natalia

📷

I am also looking for ISO 14000 series of standards. If you have others as well, it will be more than enough.

I am trying to simulate Random Road Profile Grade-C as per ISO 8608 using Shaping Filter Method equation (Eq. 15 of attachement).

The value of "Alpha" is taken as 0.127 from Table.3 shown in attached image, "Velocity of vehicle, v = 20 m/s".

But as per Simulink Model (Fig.3) "Random Number Block" is used for generating "Zero Mean Gaussian White Noise". The Random Number block used for this requires 4 inputs i.e. "Mean", "Variance", "Initial SEED" and "Sample Time".

The "Mean" is taken as "0" , "Sample Time" is taken as Simulation fixed step time i.e. 0.001.

Now I have no clue what value will be used for "Variance" and "SEED"? for this white noise.

Will the "variance" be Square of "Sigma" from Table 3? or some thing else?

Hello, I am accrediting the acute toxicity assay with Daphnia magna ISO 6341; may you suggest how to express the measurement uncertainty with the confidence interval?

Thanks in advance.

ISO/TS 16976-3:2019 Respiratory protective devices — Human factors — Part 3: Physiological responses and limitations of oxygen and limitations of carbon dioxide in the breathing environment

Does anyone have this document to consult it?

I need it for a short work.

Thanks you

Hi,

does anybody know which are the differences between standard ISO 28540 and DIN 38407-39 for PAHs analysis in water samples? Eventually, is it available DIN 38407-39 in english?

Thanks

Martina

Dear all,

I would like to conduct scratch and linear reciprocating tribo-test on my magensium alloy, which has a plasma electrolytic oxide (PEO) layer of about 20 um and 10 - 20 um of Parylene coating on top of it. So it is a double layer system.

I made a research on ASTM standard tests for scratch and linear reciprocating tribo-test and I found ASTM C1624 - 05 for the first and ASTM G133 - 05 for the second. However, I am not sure if these standards are applicable to a double layer coatings as in my system.

Are there some specific standard tribological tests for multilayer coatings?

Thanks!

Suggestions and recommendations welcome. Any usage/protocol experience would also be helpful/appreciated.

Cheers

Hi,

I warping my plates with paper, later put them in the autoclave (use wet sterilization cycle) but still some plates are get wet after ends the cycle. How to get dry the petri dishes? and if i use a oven, exist a normalized method (OMS, NHS UK, ISO) for drying the plates with a laboratory glassware oven?

Regards

I am Currently Working on Measuring Various Mechanical Properties of Metalic Materials using Universal Testing Machine (UTM) at Various Temperatures. I know that for Testing at Ambient Conditions, ASTM E8/E8M is followed.

By Literature Review, I have Identified the Specimen Dimensions for My Experiments.

Due to Lack of Adequate Experimental Data, I am Unable to Identify the Specimen Dimensions with respect to ASTM E21 and ISO 15579 for Testing at Elevated and Low Temperatures respectively.

Since, These Standards are Quite Costly to be Purchased Individually, Should I take the Specimen Dimensions at Room Temperature for Experiments at Low and High Temperatures ?

Is there a Major Difference in the Dimensions presented by these Standards or Can I Complete the Analysis using My Assumptions ?

I am a PhD student, and the doctor asked to do a lecture on ISO 9000, 14000, 17000, 118000,22000 18091,27000 and I would like to prepare the lecture. Is it possible to help me with these specifications with thanks to you

Colleagues, I am currently working on a project in my Master's Degree in Documentation that deals with evaluation indicators of digital libraries

ISO 7218 states that in cases where the number of colonies obtained in the 1st dilution is 0, the result must be calculated and presented as <1 / V * d (eg: <1/1 * 10^ -1; <10 cfu / g). ISO 19036: 2019 states that in these cases the LOQ should be calculated as <1 / 1.1 * d (eg: <1 / 1.1 * 10^-1; <9.1 cfu / g). What is your opinion on the matter?

Research suggested that standards will make a notable contribution to GDP growth. However, productivity growth in the construction sector is among the lowest of all industries over the past years, according to McKinsey. Shall standardization bodies (e.g., ISO, IEC, ITU, CEN) start standards initiatives (TC, WG, etc.) specifically for construction robots and automation?

I am currently looking for ideas on how to go about this.

I am looking for data which consists of firm name and their adoption date of ISO 9000 and if they are exporting firms or not.

Hi, everyone.

Our lab is going to use ISO 12966-2 and 12966-4 and there is one moment in sample preparation (rapid transmethylation method under alkali-catalysed conditions) that I can't understand. It is about the addition of saturated sodium chloride solution after transmethylation reaction. Maybe I'm not so good in chemistry to understand the purpose of this action. So, can anyone please help me to get it?

Hello,

we are conducting cytotoxicity tests since over an year and aren't able to get a stable test. We are no in the validation phase but there are some effects we can't explain. Here is an overview how we conduct the test in compliance with DIN EN ISO 10993-5:

- Seeding 1 x 10^4 cells in a 96-well plate (except the outer wells) --> incubate for 24 h

- Adding medical device extracts (100%, 50%, 10%, 1%) and controls:

- positive control: 1% Triton X (P)

- negative control: cell media (N)

- blank (B): media that was shaken with cell culture media for 24 h at 37 °C in the same kind of container like the medical device was shaken (in compliance with DIN EN ISO 10993-12)

- Incubation for 24 h

- Discard the media and add 50 µl MTT solution (10 mg/ml) --> incubate for 2 h

- Discard and add 100 µl Isopropanol --> incubate for 30 min

- Read out with microplate reader

See the pictures below...the cells are all the time okay until extracts and controlls are added...So something must happen at this point. Sometimes the negative control dies randomly. Sometimes the blank dies. Sometimes only one extract dilution which makes no sense. Does anyone have an idea?

Many thanks!

There are various software quality models viz. McCall’s, Boehm’s, Dromey's, FURPS, ISO 9126. What are the problems using these standards in real practice? How these standards differ from each other? Is there any global or widely acceptable software quality standard? Please provide your valuable suggestions?

Medical guidelines, prescribing how to diagnose a disease and how to treat this can be very helpful. On the other side, if a physician is obliged to follow this to the letter, it can be a burden, limiting common sense.

The same holds for ISO15189, partly helpful for improving the quality of their output and partly a burden forcing clinical laboratories into a lot of work.

What is your opinion on the balance between benefit and burden?

Hello,

I would need to understand how equation 4 of the ISO 748:207 "Hydrometry — Measurement of liquid flow in open channels using current-meters or floats" is obtained or from which source it is derived from. The equation tries to parameterize the m (exponent of the power law equation) as:

m=Cver/√g∙((2√g)/(√g+C )+0.3)

Where

g is the acceleration due to gravity (m/s2);

Cver is Chezy's coefficient on a vertical (m0,5/s).

(you can see the attachment with the ISO equation and the attachment with the whole ISO document).

Any help would be greatly appreciated.

I'm researching the use of PMI data in a MBD model for use in manufacturing.

I wasn't able to find any information about how threads (e.g. M10) and the ISO system of Limits and Fits (e.g. 20 H5) are handled within STEP AP242. In most CAD systems these are handled very well within the 3D annotations of the native model but once you export them to STEP AP242 you lose a lot of information. This limits the automated use of PMI data when exchanging this data. So I'm wondering whether I'm missing something or whether this is lacking within the STEP AP242 definition or the way it is implemented.

Any help to help me understand this is very much appreciated.

What do you think about the importance and value-add of The ISO 14040 series standards, Life Cycle Assessment? In general and especially in petrochemical industry.

I just got a new PC which I started using and I'm having trouble with kali linux VM. Now this is weird because I have experience with kali before and I am using this PC to run other VMs. I got an an ISO fitted specifically for virtualbox (32 bit kali) which I found here:

Whenever I try running it on VirtualBox i get this error: "VT-x is disabled in the BIOS for all CPU modes (VERR_VMX_MSR_ALL_VMX_DISABLED)."

I went into my BIOS settings (on ASUS motherboard, don't know the exact model but i could look it up real quick and provide it if necessary). I went under Advanced -> CPU Configurations and found Intel VT-x technology. It was greyed out and I couldn't change it but it said it was "Supported" already

I then went under Advanced Settings->System Agent Configuration Settings, and enabled the VT-d function.

Despite both apparently being enabled I am still getting the same problem and it is persisting.

My PC has no problem running a VirtualBox session with Ubuntu Server ISO so it's not an issue with virtualbox itself. This also seems to indicate VT-x is already enabled to begin with as virtualization tech is clearly supported on the PC.

thoughts?

The ISO 22301, Societal security — Business continuity management systems — Requirements, if there is some organizations have its compliance certificate, how can this be a value-added to those organizations.

The ISO 30401, Knowledge management systems —Requirements, if there is some organizations have its compliance certificate, how can this be a value-added to those organizations.

Could you please share your knowledge/experience about the relationship between STEP AP209 (ISO 10303: AP209) and CGNS:

- Does AP209 covers/supports CGNS 100%?

- Where can I read more about the relationship between AP209 and CGNS?

The AP209 web page (http://www.ap209.org/related-standards) quotes this only:

”

AP209 relates with the following standards:

CGNS (CFD General Notation System) is integrated with the STEP integrated resources

Engineering disciplines covered today by AP209 ed2 are:

Computational Fluid Dynamics (CFD), mainly based upon the CGNS standard;

”

Thanking you.

In estimating the texture distribution of asphalt mixtures, i have managed to use the discrete fourier transform on my idealized surface profile and obtained my spectral power density.

However the process of Transforming constant bandwidth spectral data to constant-percentage

bandwidth spectral data has proved challenging i would appreciate assistance in understanding and progressing from my current stage.

I have attached the excel sheet and an image of the formulas from ISO 13473-4

I am hoping to perform a simple 20 minute eeg read on subjects and convert that raw data to a metric to show which frequency each subject spends most time generating. Does anyone know of an app or software that does that very simply? I’m totally intimidated my matlab :(

thanks for any tips.

Dear RG researchers ,,,

Please for your kind help regarding Six Sigma projects & method approach in the prevention of occupational hazards accidents for fulfillment general known standard like ISO 45001.

I found 2 scientific papers

Six Sigma method approach in the prevention of occupational accidents on the solid waste collector in South Jakarta

Use Six Sigma Approach to Improve Healthcare Workers Safety

Thanks for advance

I want to know the standard procedure. For example, ISO 22196 is one of the standard guideline to test the antimicrobial activity of coatings, but it's on purchase document. Does any one know about it or any other suitable method?

Hi,

I would like to calibrate the energy scales of our XPS system, and would like to receive recommendations of suppliers that sell highly pure Ag, Au and Cu foils (thickness greater than 20 nm).

I already contacted NPL, and they can send me the supplies, however, I would appreciate to receive other suggestions.

Also, I know that ISO 15472 describes the procedure well, but are there any other procedure from which one can follow?

Thanks in advance.

Hello,

Currently in my project, I am making a hardware controller which can modify the incoming PWM signal and vary the EV A.C charging. To start of with, does anyone know which exact chapters of IEC 61851 standards to buy ? I find that there are many chapters. Basically this hardware will modify the incoming charging current from EVSE to EV according to our inputs. Any literature/material regarding this will be useful. Thanks

Regards,

Praveen

Medical Laboratories have assessments to ISO 15189 and there is also ISO 17025 for testing and calibration labs. Both involve a quality management professional system, staff competency and a laboratory director, standard operatory procedures, assay validation and verification for the intended purpose, third party internal quality control, external quality assessment and assurance, and so forth.

Through casual conversation at the Practical Surface Analysis (PSA) meeting this week in Japan, I have become aware that there is still confusion on the availability and accessibility to terms and definitions in surface chemical analysis. While the ASTM E42 vocabulary document, E673, was widely available through most research libraries in the annual volume of ASTM standards, keeping the document consistent with the ISO vocabulary standard for surface chemical analysis, 18115-1, was difficult, particularly since the ISO document was adopting many more terms and growing quickly. It was decided to withdraw the ASTM document and make normative reference to the ISO vocabulary document in ASTM standards.

As part of this change, several people (Don Baer at PNNL and Cedric Powell at NIST in particular) made great effort in getting ISO to agree to make these terms free and readily accessible. They were very successful in getting this cooperation, and now all of the surface analysis vocabulary terms are readily accessible through the IOS Online Browsing Platform (https://www.iso.org/obp/ui). Now there are several sites also hosting links to this, in order to make these terms and definitions accessible. This is a valuable resource, and is freely accessed to check terminology to be used in publications.

This ISO vocabulary document (18115-1) is also being revised, adding new terms and clarifying those that have been found to be lacking information or that are confusing.  Please use this resource, and if you find that there are necessary terms missing , or if there is confusion in any of the existing terms, please contact Dr. Alex Shard at NPL, who is the chair of TC201/SC1 and is currently actively revising this document. There is also a companion document (18115-2) for terms used in scanning probe microscopy, and these are also available through the ISO Online Browsing Platform. 

ISO 9227 do not provide any relation to test duration with life

are there a Certification Body to "ISO 8: 2019" information and documentation - presentation and identification of periodicals.

I am working on system dynamics modeling of sustainability of smart cities and I would appreciate if there is anyone who can send me or link me to the documents for these standards? I would also appreciate if you could share with me other related standards that can be freely accessed online. Thank you so much.

Greetings colleagues!

I really hope you could devote some of your time to the following: 

We are now designing a new dental implant (Class III).

During preclinical stage in vitro and in vivo studies were done. We want to verify the implant by designing a clinical trial, but before that all preclinical studies must be done.

What studies must be included in preclinics to measure safety (technical, biocompatibility etc) by ISO standards? As we know ISO-10993(bio) and ISO-14801(tech) are widely used for dental implants.

May be you can suggest a better tactics to check safety of the medical device?

I stumbled upon a comment in the new European triaxial testing standard EN ISO 17892-9. In chapter 6.3.3.6 something is written about air bearing and that they could be responsible for decrasing B-values. But what are they for?

The only function I can imagine is that an air bearing avoids the so called stick-slip-effect between the piston and the cell when increasing the axial load.

I came accross some studies and the settings of camera differ and also the opinion on it. So when I set the camera in manual mode. I will set shutter speed, ISO, F-number in combination where I will avoid blurry images but still I will get enough light. But do you think if I will use auto-focus setting it can lead to failing the aligning process? In the case of terrestrial photogrammetry the focus can differ greatly but also in some case of UAV photogrammetry. And what if I use auto ISO or shutterspeed. What is your opinion?

Three years has been gone since ISO 17034: 2016 publication. It's a reasonable time for this standard's users to have a critical practical view on the document advantages and drawbacks.

I have acceleration vs time data of array 1008*1 for 7 DOF quarter car model in vertical direction.

Simulation is of 10 seconds with step size 0.01, from where I can get matlab code for converting time domain acceleration to frequency weighted acceleration with Butterworth low pass high pass filter as per ISO 2631-1 standard.

I have simulated a 2DOF Quarter Car Model (Figure Attached) for Step Input of 0.1m. The Weighted RMS acceleration obtained is 4.768 m/s2 . The Acceleration plot on Time Scale is also attached.

I want to obtain plot between Weighted RMS acceleration Real Amplitude (m/s2) vs Frequency (Hz) Plot to compare it with ISO 2631 standards. I tried to obtain it using Magnitude FFT and Vector Scope block but result is showing very high amplitude of 600.

Simulink Model is Also Attached.

How to Obtain the correct plot?

Detergent powder for washing

I am trying to determine the exact length of pipe required for my rig design to help effectively mix water droplets with the incoming air flow. For calculation purposes, my water droplet size (MVD) would be around 20 microns and the water content will be around 20g/kg of dry air.

Is there a method of calculation or a standard in BSI/ISO or ASME that deals with this for a straight, cylindrical pipe?

what if universities in India adopt ISO certification like industries take ISO certificate to show their quality standards.

can this phenomena will be helpful to Indian education system to improve their quality of education?

Greetings,

I am cultivating Daphnia magna for a while now and after a sudden change in the temperature (to 17 degrees during a weekend) they have not been able to recover.

They are still able to breed neonates (some of them), but soon some adults (a lot of them) and even neonates are found dead in the bottom of the beackers.

The daphnids are cultivated in medium ISO and fed with R. subcapitada.

Is there some way to imrpove the culture? Maybe the temperature was not the problem and there is something wrong with my culture (parasites?).

I have been trying for 3 generations now, but it seems that they can't recover. Can someone help?

Regards,

Giuliana.

Since I need a large number of experiments that are carried out under different climatic conditions, I would like to ask you to help me with this.

I developed a test object with elements of the standard DIN EN ISO ASTM 52902 and additional features. I would send you the STL file of the test object, description of the settings for the experiment and a test report for evaluating, if you contact me.

The OECD provides a method to determine WHC. I have found that this is not transferable to "real" soils, and am investigating alternative methods. I would welcome advice about the OECD method or alternative methods from researchers.

I'm planning an experiment with ISO 527. I would like to know what the difference are when testing a type A ( with narrow parallel-sided section and tabs) compared to a type B (rectangular shaped) test specimen. I'm also planning to conduct a ISO 178 flexural strength test and therefore it seems appropriate to choose type B, since the dimensions for type B in ISO 527 and ISO 178 are the same.

Hello Dear concerned polymer scientist or technical fellows, I am looking for a four point probe measurement system to buy, which will be easier to use and test my polymer hydrogel may be in both dry and wet condition. I am not sure if I can use Four point probe to see the surface resistivity of wet hydrogel. So any kind of idea, link, company name or help will be highly and cordially appreciated. I don't have any rough idea about how much the surface resistivity of my hydrogel could be. so possibly looking for some suggestion (the more resistivity range the better). Eagerly waiting for your response. Thanks

ISO 4288 is an old standard defining defaults for profile roughness measurement. Sometimes the defaults can be used. Sometimes they cannot be used. This discussion is not if the defaults make sense or not. It is about how to use the defaults.

Most people know: if the Ra is between 0.1 and 2µm use a cut off 800µm and 4mm length.

But this is not 100% true.

ISO 4288 includes 3 tables. Most of you know the first table gives the relation between Ra and the sampling length which by default is the same as the cut off. But this table is only for aperiodic profiles!

Table 3 of ISO 4288 is for periodic profiles. The table gives the relationship between Rsm (approx. the period of the profile) and the cut off.

So, the definition is that first look if the profile is periodic or not and then look into table 1 or table 3.

Very clear. Nothing new.

No, it is not clear! Even experts are only using table 1 of ISO 4288 and they do not look if the profile is periodic or not. Last week an expert wrote that a sinusoidal roughness artefact (this is periodic) with an Ra of 500nm and a Rsm of 50µm must use 800µm cut off. Table 1 theoretically says 800µm cut off but table 3 says 250µm (table 3 is the right one)!

Periodic profiles are very common. Normally turned surfaces have periodic structures. Very often roughness artefacts have periodic profiles.

Question/Discussion:

What is your opinion?