Product Overview

Description

 

MQ-136 hydrogen sulfide sensor module MQ136 hydrogen sulfide detecting sensor

 

Specification:

 

 

First, size: 32mm X22mm X27mm length X width X height

 

 

 

Second, the main chip: LM393, ZYMQ-135 gas sensor

 

 

 

Third, the working voltage: DC 5 V

 

 

 

Four characteristics:

 

 

 

1, having a signal output instruction.

 

 

 

2, the dual signal output (analog output and TTL level output)

 

 

 

3, TTL output valid signal is low. (When the output low signal light can be directly connected to the microcontroller)

 

 

 

4, 0 ~ 5V analog output voltage, the higher the concentration, the higher voltage.

 

 

 

5, hydrogen sulfide, liquefied petroleum gas, natural gas, city gas, smoke have better sensitivity.

 

 

 

6, with a long life and reliable stability

 

 

 

7, rapid response recovery characteristics

 

 

 

V. Application:

 

For home or factory gas leakage monitoring device, suitable for liquefied petroleum gas, butane, propane, methane, alcohol, hydrogen, smoke and other monitoring devices.

 

 

 

Applications: SCM learning, electronic competition, product development, graduation design. . .

 

 

 

[Label description]

 

 

 

Explanation: This module MQ-135 hydrogen sulfide sensor, please use the warm-up before about 20S:

 

 

 

The first step: to the module for 5V DC (note the positive and negative do not reversed, otherwise easy to burn the chip).

 

 

 

Step Two: If you choose to DOUT, TTL high and low ends of the output signal can be directly connected to the microcontroller IO port or connect an NPN type transistor to drive the relay, potentiometer RP here for adjusting the output level of the transition threshold, by the FIG schematic can be analyzed, when the sensor detects the measured gas, the comparator LM393 pin 2:00 voltage value detected with the sensor is proportional to the gas concentration, when the concentration exceeds the threshold set by the potentiometer RP when, comparator 2 pin point higher than 3 feet of the point, this time, the comparator output low 1 foot, LED lights, R3 limiting resistor for LED lights, C1 for the filter capacitor. Sensor output low, on the contrary, when there is no signal when the sensor output high, equal to the supply voltage.

 

 

 

Step Three: If you choose to AOUT, analog output, so you do not have control potentiometer, the AOUT pin is connected directly to the input of the AD converter or the microcontroller with AD function on it. According to our experience: in a normal environment, namely: no measured gas environment, set the sensor output voltage is the reference voltage, then the voltage AOUT end at around 1V, when the sensor detects the gas being measured, the voltage of each increased 0.1V, the actual concentration of the measured gas increases 200ppm (simply say:. 1ppm = 1mg / kg = 1mg / L = 1 × 10-6 used to indicate the gas concentration, or concentration), based on this parameter can be will be converted into concentration values in the microcontroller inside the analog voltage values measured. Note: If you are used to make precision instrument, please buy on market standards to calibrate the instrument, or there is an error, because the concentration ratio of the output voltage relationship is not linear, but tends to be linear.

 

 

 

Special note: the sensor is powered, needs to warm up around 20S, measured data becomes stable, sensor fever is a normal phenomenon, because the internal electric wire, if not normal hot.