| 摘要 |
PURPOSE:To compensate the change in electric resistance with a change in the temp. of sample specimen by measuring the voltage of the part other than the voltage impressed part in the sample specimen and impressing voltage to the sample while controlling current in such a manner that this is kept constant. CONSTITUTION:A cataphoresis chamber 2 is put in a thermostat 1 provided with a temperature controller 4 and is kept at a constant temp. An automatic sample injection port 5 and a discharge port 6 are opened and closed to supply the sample into the chamber 2. When it stabilizes, DC current is supplied to electrodes 3, 3' by a DC power source device 7 so that the voltage across voltage detecting needles 12, 12' remains constant. The signals from the needles 12, 12' enter a unidirectional polarity converter 17 so that they assume a unidirectional polarity before they enter the DC power source device 7, thereafter, they enter the DC power source 7'. The sample in the chamber 2 is moved by the electric field between the electrodes 3 and 3', and the degree of its migration is measured with a microscope through a peep window 9. Thereby, the effect of Joule heat etc. by the supply current is eliminated. |
