| 摘要 |
The electrical resistance of specimens formed on test coupons is measured by a method and apparatus in which a test voltage applied to each specimen yields a leakage current. An operational amplifier having very high impedance inputs receives the leakage current signal and generates an output voltage that is very low in magnitude and varies in the leakage current. The test voltage is applied to a plurality of specimens and leakage current from each specimen is simultaneously converted by operational amplifiers whose very low impedance outputs are applied through switches in a sequential fashion to an analog to digital converter whose output is fed to a central processing unit wherein the leakage current is computer in terms of the resistance of the electrical insulation under examination.
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