TWO-PORT DEVICE PARAMETER METER Russian patent published in 2000 - IPC

FIELD: physical quantities measurement technique. SUBSTANCE: meter has square-pulse generator 1 whose first terminal lead is grounded and is common for its two outputs, two-port device with adjustable components, and two-port device under measurement each assembled of resistor and capacitor. One lead of these two-port devices is grounded and other one is connected to generator second lead which relates to its first lead. Input of noninverting voltage follower 6 is connected to common lead of two two-port devices and output, to noninverting amplifier 7 whose gain equals 2. One input of double-input adder 8 is connected to output of inverting amplifier and other one, to generator second lead. First lead of null-point detector 10 that functions as synchronization input is connected to generator second output that functions as synchronization output and second one is connected through isolating capacitor 9 to output of analog adder. Such circuit arrangement eliminates error component brought in by common- mode signal. EFFECT: reduced measurement error. 2 cl, 1 dwg