HIGHLY ACCURATE INDUCTION TYPE SODIUM LEVEL METER

摘要

PURPOSE:To facilitate a calibration by performing a linearity correction and a zero point temperature correction on A/D-converted level detection signals by folded line correction data and square curve temperature correction data stored in advance. CONSTITUTION:Voltage signals induced in the secondary coil of an induction type sodium level meter 31 in a tank 30 are applied to a signal converter 36 via a transmission line 35 to be converted to the wave signals of several mA - twenty and several mA. On the other hand, data for a linearity correction, zero point temperature compensation data, calibration data, operational program and the like are stored in a ROM 52. An MPU 50 performs the calibration and correction of the linearity of the output signals of an A/D converter 37 inputted to and stored by a RAM 51 and the temperature effect value of a zero point by the data and program stored in the ROM 52. In this case, by preparing a program so as to determine the zero point and a span point, only raising a liquid level from a lower limit enables the calibration to be performed without the operation of a worker.