Gas sensor registers the presence of VOC gasses: toulen, alcohol, acetone and hydrogen. It registers gases the best while they are in the liquid form, but since we cannot find them in that state that often, it measures a good concentration of substances in a gaseous state. It takes a short time to heat up in order to work correctly.

The breakout board works with both digital (DO) and analog signals (AO). The digital output is obtained by setting a threshold value with a potentiometer. The analog output will differ depending on the intensity of the gas.

• Voltage: 5V
• Digital(HIGH/LOW) and analog(0V-5V) output
• With LM393 comparator
• Dimensions: 22 x 38 mm

Find VOC sensor MQ138 breakout on Soldered website.