Described in this paper is a systematic and generalized analysis of dynamometer type phasemeter using “magnetic-field ratio” as a parameter and a theoretical explanation of the characteristics of scale, frequency, waveform and mutual induction. It also deals with an uniform-scale phasemeter with high accuracy developed as a result of the above. Extension of this study resulted in the invention of a more sensitive zero method phasemeter of wider application.

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The precision wire wound type potentiometer is widely used as an electromechanical transducer for self balancing type instrument, electronic analog computer, etc. because of its excellent features such as high accuracy, simple structure and easy handling.
Excellent it is, it has some big difficulties in practical uae, such as the wear of the wire and contact, increase of contact noise, etc., which often have beeh discussed up to this time. Still, it has never been paid attention at all that the thermal EMF in the potentiometer circuit affects some characteristics of the self balancing type instrument.
In this paper, the above fact is discussed both experimentally and theoretically. The thermal EMF of the potentiometer circuit in the self balancing type instrument can be classified into the following two types:
1. Static thermal EMF
2. Dynamic thermal EMF
(a) Mean temperature rise of contact.
(b) Local and short-time thermal flash at contact.
The static thermal EMF is generated by the temperature gradient which exists in each component made of different kinds of metals. Its malfunction appears as a long time drift of indication of the instru ment. The dynamic thermal EMF is generated by the temperature rise of the contact caused by sliding friction, (a) of the above classification affects dynamic characteristics of the self balancing type instrument and (b) is considered to have close relations with the wear of the wire and contact and with the increase of the contact noise of the potentiometer.
The authors made it possible to explain the mechanisms of the dynamic EMF and its influences to the self balancing type instrument. Through this analysis, the transfer-function of the potentiometer circuit, G_H, is represented as follows:
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During its derivation, the temperature rise of the contact is assumed to follow Newton's low ol cool ing. The result of the calculation by using the above transfer-function well proves the experimental fact that the dynamic response of the itstrument is different by sliding direction.

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With a special purpose computer built in, latest numerically controlling milling machine has many distinctive features as follows;
1) Approximate straight or circular line by means of stair case function.
2) Informations necessary for cutter offset are given by operating Panel of equipment.
3) Employ an open loop control and has no feed-back loop.

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Transfer function of liquid composition of arbitrary tray of binary distillation column is derived here for reflux flow change and vapor flow change. Material balance equations are derived on several assump tions and then Laplace-transformed. The signal flow diagram drawn from the equations is reduced into asimpler form. The transmittances in the diagram are expressed in the form of continued fractions, which are reduced into a compact form by averaging the elements in the continued fractions and using the complex hyperbolic functions. The transfer function for arbitrary tray is expressed in the form of containing the hyperbolic functions. This method of obtaining the transfer function is free from physically unreasonable boundary conditions which are inevitable in the case of solving material balance equations as finite difference equations. The time for calculating frequency response from the transfer function is independent of the number of trays. This feature is quite advantageous in the case of large number of trays. Frequency responses calculated from the transfer function in the case of methanol-water distillation column of sixtrays are compared with the strict solutions of material balance equations. The calculated values well approximate the strict values in the important frequency range of phase lag of π/2-π radians.

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In measurement of electric conductivity solution, the error due to polarization is often caused. The new method described in this report is of a system of three electrodes and makes an accurate measurement because it is free from the error by polarization. In this method, one additional electrode is combined with the two electrodes of the conventional Kohlransch's Bridge system to eliminate the effect of polarization. Described in detail are its principle, features, temperature compensation method and an example of its application. When an industrial instrument manufactured based on this principle was used at a sewerage treatment station for ten months, good results were obtained.

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This paper presents the theoretical and experimental analysis of step response of pulse-motor. At first, by introducing the “equivalent torque time constant”, the fundamental differential equation of step response is obtained. Solutions of this equation are Bessel function, whose order is pure imaginary number, and Lommel function. Since the Bessel function of imaginary order has seldom or never been discussed in the existing literatures, the author establishes a form of solutions convenient to the numerical calculation. Next, by using a small size synchro control transformer, a simple method of measuring the step response of pulse-motor is presented. If the value of “equivalent torque time constant” is decided by comparing theoretical data with measured ones, the solutions described in this paper coincide with the experimental results fairly well.

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