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一、引言电子管伏特计(或称真空管电压表)是测量电压的一种电子仪器,它的主要用途是用来测量交流电压. 电子管伏特计实质上是一个电子管检波器(整流器),利用所得整流电流的直流分量是和被测交流电压成正比的关系,再通过灵敏的磁电式表头(微安计)得到电压指示. 电子管伏特计最可贵的特性是,它的指示响应可以在很宽的频率范围内与频率无关,往往可以将对50赫所作的校准曲线一直使用到高达30兆赫或更高的频率.其次,在测量时,它不致扰乱被测电路,它所消耗的信号功率是微不足道的,因为它有很高的输入阻抗,一般相当于一个很大的电阻(几百千欧到几兆欧)与一个小电容(1或2微微法)并联,所以对被测电路的负载作用极小.在利用仪器内附的分压器时,交流
I. INTRODUCTION V-tube voltmeter (or vacuum tube voltmeter) is an electronic instrument for measuring voltage and its main purpose is to measure AC voltage.The tube voltmeter is essentially an electronic tube detector (rectifier) that uses the resulting rectified current The DC component is proportional to the measured AC voltage and is then voltage-gated by a sensitive magnetic meter (microammeter) The most valuable characteristic of a vial voltmeter is that its indication response can be varied over a wide frequency range Often independent of frequency, the calibration curve made to 50 Hz can often be used up to 30 MHz or higher. Second, it does not disturb the circuit under test, and the signal power it consumes is negligible, Because of its high input impedance, which is generally equivalent to a large resistance (hundreds of ohms to several megohms) in parallel with a small capacitor (1 or 2 picofarad), the load on the circuit under test is extremely small Communicate when using the voltage divider attached to the instrument