Air quality sensor
SQA

Air quality sensor.
Automatically switches the fan on when the quality of the ambient air deteriorates below an acceptable level due to fumes, odours, tobacco, smoke or dampness, etc.
Adjustable run-on-timer facility which enables the fan to operate for a pre-selected time period after the air quality sensor has switched off.
Important: this sensor must not be used to detect combustible gases or fires and in connection with any safety alarm systems.