In order to make an accurate and efficient test of thermocouples by comparing them with standard thermocouple, the authors have installed six electric furnaces, each designed to be kept at the fixed temperatures with the intervals of 200 deg between 200°C and 1200°C.
When the tested thermocouples are different from the standard one in diameter or the wires of the thermocouples are unhomogeneous owing to their exposure to high temperature, errors are likely to occur due to the change of the depth of immersion. These causes are analytically ascertained by means of the above-mentioned furnaces. As a result of the analysis it has been proved that, in order to make an accurate test, it is necessary that the furnaces should be more than 70cm. long and that the area having an uniform temperature should be more than 20cm. long in its middle part.
In any case, the standard thermocouple should be stabilized by suitable annealing and its wires should be homogeneous. As a result of the investigation of thermoelectric character in actual PR and CA thermocouples, it was found that most thermocouples came up to the 0.5 or 0.75 class in "JIS C 1602", and these thermoelectric characters of the products of each maker had the constant deviation from those of reference table. Especially, those of the PR thermocouples were similar to those of the reference table of N.P.L.

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Permanent magnet, if once fully magnetized, retains magnetism permanently, but its intensity does not remain constant, and normally decreases gradually with elapse of time.
This change is known as ageing of permanent magnet, which is caused either naturally or by external disturbance, the latter case being the main subject of concern in this paper.
The external disturbance mentioned above can be classified into the following four types according to characteristics;
a) reluctance change of magnetic circuit.
b) application of outer field.
c) mechanical shock.
d) temperature change.
In the first three cases of a), b) and c), the general functional relations have been found between the change of the intensity and the number of repetition of the disturbance or its total repetition period. It proves that the change of the intensity increases in proportion to logarithm of the number of repetition or the total repitition period. Any general relation, however, has not been found in the case of d).

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The computation of flow and pressure of the networks of fire-extinguishing pipeline becomes more tedious as the networks grow larger.
But the electrical simulation of such systems are not so easy, because the frictional head loss in a pipeline is not proportional to the amount of flow. So the resistance element with special characteristics should be used for such purpose.
After several experiments the voltage-current characteristics of straight filament vacuum lamps was found to be most appropriate to simulate the pressure-flow characteristics of the pipelines.
To improve characteristics of the lamp, the filament was connected in parallel or in series in the bulb according to the voltage coefficient of the lamp, and the results were proved very satisfactory.
A series composed of about 250 lamps was prepared to simulate the pipelines of various lengths, diameters, materials and ages. And an analyzer of the pipeline network was composed and computation was conducted on the simple networks.

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