FETVM-FET Voltmeter

This is a circuit of FETVM-FET Volmeter. The function of the VTVM is replaced by the FTEVM while at the same time ridding the usual line cord instrument. This circuit can allow a 0.5 volt scale range because drift rate of FETVM are superior to vacuum tube circuits. Here is the circuit:

The 2N4340 are implemented on this circuit because it has low noise and low leakage. [Source: National Semiconductor Application Notes]