DEVICE WHICH MEASURES EQUILIBRIUM ELECTRODE POTENTIAL Russian patent published in 1997 - IPC

FIELD: instruments which measure water hardness and pH level. SUBSTANCE: output of first voltage divider is connected to inverting input of amplifier. Output of second voltage divider is connected to on-inverting input of amplifier. Unit for alternation of level of feedback circuit is designed as voltage- controlled linear resistor which may be resistive matrix which is controlled by voltage. Said unit is introduced into arm of first voltage divider and is connected to common line. In addition device has memory unit and second amplifier, which input terminals are connected between non-inverting input of first amplifier and common line. First terminal of detector is connected to non- inverting input of first amplifier through second input of first commutator. EFFECT: increased precision, increased number of constructive members. 1 dwg