MQ-135 Sensor

An air quality sensor responding to a broad group of pollutants including ammonia, nitrogen oxides, benzene, smoke and carbon dioxide. Best used as a relative air quality indicator: rising readings mean the air is getting worse, which is genuinely useful for ventilation control and indoor monitoring. It cannot tell you which gas is present or give a calibrated ppm figure without laboratory calibration against reference gases. Needs one to two minutes of warm-up and draws around 150 mA continuously. Broad response to common indoor air pollutants; Analogue output plus adjustable digital threshold; Good trend indicator for ventilation control; Long operating life in normal indoor air