In this technique the specimen is cemented to a quartz rod of identical cross section and resonant frequency of the composite system (fc) is determined using the apparatus. The resonant frequency of the quartz crystal (fq) is also determined. From the knowledge of fq, fc and the masses of the quartz and the specimen, the resonant frequency of the specimen is evaluated using the relation

Instrument : It consists of Piezoelectric Oscillator, power supply, quartz rod, holder, quartz rod with sample, connecting cables and R.F. Meter.

Accessory : Any general purpose C.R.O. (not supplied with the instrument)