DEVICE FOR MEASURING TEMPERATURE-CONDUCTIVITY COEFFICIENT OF MATERIALS Russian patent published in 1995 - IPC

FIELD: thermal-physical measurements. SUBSTANCE: quick-response thermal converter of the device is mounted onto unheated surface of the sample to transform temperature of the surface into electric signal. The signal has variable component of voltage with frequency of temperature wave received. Output voltage of the converter enters one input of differential low frequency amplifier. Low frequency signal enters the other input of the device from the generator, which signal is frequency-, amplitude- and phase transformed. As power of quick-response converter pulses with frequency, which is equal to doubled value of frequency of the generator, then frequency of signal, which enters the second input of differential amplifier is doubled by means of frequency doubler. In order to put amplitude of doubled frequency signal to the level of signal at output of the thermal converter, calibrated attenuation of signal of voltage divider is conducted for so many times, for how strong temperature wave is attenuated in the sample under control, when temperature wave is equal to thickness of the sample under control. Signal is delayed by electric delay unit for time, which is equal to total thermal time constant of quick-response heater and receiving quick-response thermal converter. EFFECT: improved precision of measurement. 1 dwg