Kamekichi SHIBA’s research while affiliated with Toyo University and other places

The capillary viscometer for gases of steady flow type reported here is a device of measuring the viscosities of gases in a steady state. The measuring principle of the present viscometer is based on the previously developed Hagen-Poiseuille's law for gases. The viscosities can be obtained by a constant flowrate of a liquid and the pressure difference of both ends. The outlet of the capillary tube is open to atmosphere. This simple trial viscometer enables us to measure the viscosities of gases easily. Experimental results show that the obtained values are in good accordance with known reasonable values.

The velocity distribution at the inlet of a capillary viscometer is determined by the flow before the viscometer. Therefore, this flow is considered to affect the measurements of viscosity by the capillary viscometer. By the theoretical considerations applying Bernoulli's theorem and Newton's law of motion to the flow, the effect is indicated as πa²Δp and let MA be the momentum flowrate at the inlet of the capillary tube, it is known as MA>πa²Δp>1/2MA.

The purpose of this work is to make an attempt to clarify the so-called end correction of a capillary viscometer on the foundation of the theory reported in a previous paper, and to formulate the relation between the measured quantities and viscosity. Some experiments were carried out by using two capillary tubes, short and long, with equal diameters. It is observed that the experimental results agree fairly well with the theoretical con-siderations.

A thermoelectric bimetal thermometer is a thermally grafted thermometer composed of a thermocouple and a bimetal thermometer. The measuring principle of the thermoelectric bimetal thermometer is as follows: The temperature of the bimetal is so controlled that the difference between the measured temperature and the bimetal temperature is equal to a present value. Practically, the electromotive force of the couple is equal to the set value by adjusting the temperature of the bimetal. Experiments are carried out by a trial thermoelectric bimetal thermometer. The both temperatures obtained by the thermoelectric bimetal thermometer and by a thermoelectric thermometer with the reference temperature of 0°C agree fairly well.

A thermoelectric transistor thermometer is a grafted thermometer composed of a thermocouple, a transistor thermometer and a suitable operational amplifier which needs no reference temperature. The proportional constant γ of the transistor thermometer is adjusted to be equal to the temperature coefficient β of the thermocouple by means of an operational amplifier, and the sum of the e. m. f. and the voltage of the transistor thermometer is measured. It is proved theoretically that the temperature to be determined is known from the measurement of the voltage. Experiments are carried out with two typical circuits, one which enables us to measure the sum of e. m. f. of the thermocouple and the voltage of the transistor thermometer, and the other to measure the sum of the voltages multiplied by n. Results of experiments show that the outputs of the trial thermoelectric transistor thermometer agree fairly well with the e. m. f. of a thermoelectric thermometer of the same kind with the reference temperature of 0°C.

A bimetallic psychrometer of temperature-difference and temperature type is composed of a compound bimetallic differential thermometer and a bimetallic thermometer. The compound bimetallic differential thermometer is constructed from two helical coils of bimetal connected in series, of which the senses of thermal deflection are mutually opposite and the angular def-lections for the same temperature change are equal. The helical coils of the bimetal used are 4 mm in diameter and 40mm long, and are connected to the ends of a plastic rod 50mm long. A suitably adjusted compound bimetallic differential thermometer gives accurate temperature differences. One of the helical coils of the bimetal serves as the wet thermometer and the other serves as the dry thermometer. It is found experimentally that the necessary minimum air velocity for the bimetallic psychrometer is about 0.7m/s. Experimental data show that the Sprung's psychrometric formula holds well for the bimetallic psychrometer.

With a usual hot wire anemometer, air velocity is determined by utilizing the relation between the electric current, the temperature of a single heated resistance thermometer wire and air velocity. And the effect of the temperature of air to be measured is considerably large. Therefore it is necessary to heat the resistance thermometer wire to a tolerably high temperature. The double hot wire type anemometer, here reported, utilizes the relation between the electric current, the temperature rises of the double wires and air velocity in order to determine the air velocity. That is, instead of a single wire, double resistance thermometer wires are placed in air flow and the difference of the temperature rises between the two wires is utilized. Experimental results show that the effect of the air temperature is extremely small, and it is known that the air velocity can be measured with small temperature rises.