The invention relates to a
measurement device and method for a
differential capacitance type instrument. The device comprises an alternating
excitation signal generator, a circuit option switch circuit, an AD (analog-to-digital) converter and a
digital signal processor, wherein after the alternating
excitation signal generator generates an alternating
excitation signal with
fixed frequency and fixed amplitude, the alternating excitation
signal is applied to two ends of the
differential capacitance type instrument through the circuit option switch circuit to realize positive excitation and negative excitation of the
differential capacitance type instrument; the output end of an intermediate polar plate of the differential
capacitance type instrument is sequentially connected with the AD converter and the
digital signal processor, the spectrum data amplitude maximum value acquired by converting the output
signal of the intermediate polar plate of the differential
capacitance type instrument in the positive excitation and the negative excitation, a variation of a measured
physical quantity of the differential
capacitance type instrument is acquired according to a certain
linear relationship, so that the differential capacitance type instrument can be measured. According to the
measurement device, a high accuracy measurement result can be acquired for the differential capacitance type instrument, so that the reliability of a differential resistance type sensor can be improved.