Compact board based on the MQ-131 sensor. Equipped with a high sensitivity and a very fast response time, this sensor is able to detect the ozone concentration (10～1000ppb) in ambient air. The sensor's sensitive material is tin dioxide (SnO2), which has a low conductivity, when the air is clean in the environment, while it is higher in the presence of ozone.

The board has a trimmer to set the threshold value, analogue output and digital output (TTL), status LED for power supply and output signal.

The digital output can be connected directly to a microcontroller. The analogue output provides a voltage (0-5 VDC) that increases with increasing ozone concentration in the air.

Power supply: 5 VDC, dimensions (mm): 31.85x19.65x33. It can be used with Arduino or other microcontroller.

The ozone (chemical formula: O₃), it is s a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O₂, breaking down in the lower atmosphere to O₂ or dioxygen. Ozone is formed from dioxygen by the action of ultraviolet light (UV) and electrical discharges within the Earth's atmosphere. It is present in very low concentrations throughout the latter, with its highest concentration high in the ozone layer of the stratosphere, which absorbs most of the Sun's ultraviolet (UV) radiation.

Ozone's odour is reminiscent of chlorine, and detectable by many people at concentrations of as little as 0.1 ppm in air. Ozone's O₃ structure was determined in 1865. The molecule was later proven to have a bent structure and to be diamagnetic. In standard conditions, ozone is a pale blue gas that condenses at progressively cryogenic temperatures to a dark blue liquid and finally a violet-black solid. Ozone's instability with regard to more common dioxygen is such that both concentrated gas and liquid ozone may decompose explosively at elevated temperatures or fast warming to the boiling point. It is therefore used commercially only in low concentrations.

• Ozone sensor: MQ-131
• Sensor type: seminductor
• Ozone detection range: 10～1000ppb 
• Power supply: 5 Vdc
• Status LED for power and output signal
• Digital and analog output:
   - analog output (0-5 VDC): the voltage increases as the ozone concentration in the air increases
   - digital output: TTL (0-5 VDC): to be used to get a threshold value, set via trimmer, to manage it via a microcontroller
• With a long life and reliable stability
• Fast response characteristics
• With mounting holes to facilitate fixed installation
• The probe can plug design for easy testing
• It can be used to create devices that can detect ozone at home and atmospheric environment

• Datasheet MQ-131