PORTABLE GAS DETECTING APPARATUS

摘要

PROBLEM TO BE SOLVED: To obtain a portable gas detecting apparatus in which the adjustment of an alarm level is not required and which prevents an inessential alarm from being issued. SOLUTION: A gas sensor 12 which outputs a detection signal corresponding to the gas concentration of a fluid taken into a chamber 10 is provided. A dead-band-level generation means 19 which outputs a voltage signal agreeing with a selected level is provided. A differential amplifier 20 which outputs the difference between the detecting signal and the voltage signal is provided. An analog-to-digital conversion means 31 by which a signal from the differential amplifier 20 is converted into a digital signal is provided. A display panel 4 which displays the digital signal is provided. A buzzer 33 which issues an alarm when the detection signal exceeds a set level is provided. Thereby, the detection signal which is less than a dead-band level is offset, it is not required to change an alarm level, and it is possible to prevent an inessential alarm.