DETECTOR FOR FOURIER-TRANSFORMATION INFRARED SPECTRAL PHOTOMETER

摘要

PURPOSE:To improve the S/N of detecting signal of a pyroelectric detector by constituting the device so that in a temperature control mechanism, the power supply to an electronic thermal element is started or cut off in a period in which a data collection of the detecting signal from the pyroelectric detector is not executed. CONSTITUTION:Signals A, B from a comparator 26 obtained by comparing a detection output of a temperature sensor 14 and a reference voltage Vr are inputted to a control unit 28. In an (EOC) signal of A/D conversion, the A/D conversion is started at its rise, and ended at its fall. When the signal A is in a low level at the time point of a fall of the (EOC) signal, a signal for turning on a driving transistor 30 for a Peltier element for heating is outputted from the control unit 28, and if the signal B is in a low level at the time of falling the (eoc) signal, a signal for turning on a driving transistor 32 for a Peltier element for cooling is outputted from the control unit 28. In the case of a temperature is set to 60 deg.C in order to execute the detection in a state that the S/N is large as a detector 8, a PID control is executed, but from the viewpoint of recognizing an error temperature, the shorter the time extending the start of the power supply to the Peltier elements 10, 12 to its cut-off is, the better it is.