technical data MQ-131 gas sensor features fast response and high sensitivity stable and long life simple drive circuit wide detecting range application they are used in air quality control equipments for buildings/offices, are suitable for detecting of o 3 . specifications a. standard work condition symbol parameter name technical condition remarks vc circuit voltage 5v0.1 ac or dc v h heating voltage 6v0.1 ac or dc r l load resistance variable r h heater resistance 31 ? 5% room tem p h heating consumption less than 1100mw b. environment condition symbol parameter name tech nical condition remarks tao using tem -10 -50 tas storage tem -20 -70 r h related humidity less than 95%rh c. sens itivity characteristic symbol parameter name technical parameter remark 2 rs sensing resistance 100k ? -200k ? (50ppb o 3 ) o 3 (100ppb/50ppb) concentration slope rate 0.65 standard detecting condition temp: 20 2 vc:5v0.1 humidity: 65%5% vh: 6v0.1 preheat time over 24 hour detecting concentration scope 10ppb-2ppm o 3 d. structure and configuration, basic measuring circuit a? parts materials 1gas sensing layer sno 2 2 electrode au 3 electrode line pt 4 heater coil ni-cr alloy 5 tubular ceramic al 2 o 3 6 anti-explosion network stainless steel gauze (sus316 100-mesh) 7 clamp ring copper plating ni 8 resin base bakelite 9 tube pin copper plating ni fig. 1 free datasheet http:///
structure and configuration of MQ-131 gas sensor is shown as fig.1 , sensor composed by micro al 2 o 3 ceramic tube, metal-oxide semiconductor sensitive layer, measuri ng electrode and heater are fixed into a crust made by nylon and stainless steel net. the heater provides necessary work conditions for work of sensitive components. the enveloped MQ-131 have 6 pin ,4 of them are used to fetch signals, and other 2 are used for providing heating current. electric parameter measurement circuit is shown as above fig.1. e. sensitivity characteristic curve fig.3 sensitivity characteristics of the MQ-131 application resistance value of MQ-131 is difference to various kinds and various concentration gases. when using this components, sensitivity adjustment is very necessary. we recommend that you calibrate the detector for 50ppb o 3 in air and use value of load resistance that( r l ) about 100 k ? (50k ? to 200 k ? ). when accurately measuring, the proper alarm point for the gas detector should be determined after considering the temperature and humidity influence. noting: there are a round hole in the up and down side of the sensors, this design enable the sensor inner gas to exchange better with outside air, and the sensor shall has higher sensitivity, quicker response and resume time with a fan . reference application circuit: fig.3 is shows the typical sensitivity characteristics of the MQ-131 for several gases. in their: temp: 20 humidity: 65% o 2 concentration 21% rl=20k ? ro: sensor resistance in the clea n air. rs: sensor resistance at various concentrations of gases. free datasheet http:///
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