Measurement of the electrical characteristics of quartz crystal units by use of a bridged-tee network

A bridged-tee null network has been used to measure the equivalent resistance and the equivalent reactance of a quartz crystal plate. This measuring circuit has the advantages that shielding is relatively simple (both the source and the detector have a common grounded terminal) and that corrections for all stray capacitances that affect the measurements may be included in the calibrations of the capacitors of the tee. The precision of the measurements is estimated to be 0.3 per cent for the determination of the equivalent reactance and 2.3 per cent for the determination of the equivalent resistance.