| 摘要 |
<p>PURPOSE:To improve measuring accuracy and reliability, by providing the titled circuit with the 1st switch and the 2nd switch to be closed to prevent a logarithmic ampifier from the abnormal rise of output voltage when an input signal exceeds a required level, without connecting a switch to an input transmission line of the logarithmic amplifier. CONSTITUTION:Since the 1st and 2nd switches 20, 30 are opened respectively in normal measuring status, a measured value is outputted from an deviation amplifier 6. At the completion of measurement, the output of a preamplifier 1 is turned to ''0'', so that the 1st switch 20 attached to the passage connecting between a constant voltage source 8 and the input of the logarithmic amplifier 4 is closed. Constant voltage V0 applied from the constant voltage source 8 at that time prevents the output of the logarithmic amplifier 4 from extending to infinite.</p> |
