Study and proposal of alpha-grade evaluation procedure for synthetic quartz crystal

The authors studied the measurement method of alpha values on synthetic quartz, to solve the discrepancy of grade evaluation between different wavenumbers that is involved in IEC 60758 second edition 1993-04, and to minimize alpha value difference between different measuring instruments. The solution is proposed in this paper. Those are proper instrument calibration, standard samples and the values, and new alpha grade table. The result can be applied to Fourier Transform Infrared Spectrometer (FTIR).