LVDT calibration using a phase modulation optical interferometer calibrated by an x-ray interferometer

Abstract

We have calibrated an LVDT using an optical and x-ray interferometer. We have calibrated optical interferometer using x-ray interferometer. The LVDT has calibrated by the optical interferometer. We made the monolithic x-ray interferometer with a double parallel spring structure for the translation of an analyzer lamella. One period of the xray interference fringe corresponds to the lattice parameter, 0.192 nm. The nonlinearity of optical interferometer has been calibrated by an x-ray interferometer. We have used a phase modulation optical interferometer. This calibration using the x-ray interferometer is directly traceable to primary standards. We have achieved the resolution of an xray interferometer and optical interferometer better than 0.01 nm. The optical phase stability of the interferometer is less than ± 150 pm. For the control of environmental temperature, we have used PID method. PID controller controlled the temperature inside chamber. Temperature drift was less than ± 3 mK (k = 2).

The Calibration of Displacement Sensors

“…The results show good agreement between the two instruments, although some minor differences of less than 5 pm have been observed [60]. An X-ray interferometer, combined with a laser interferometer, was used for the calibration of LVDT's by Park [61].…”