MQ139 Gas Sensor Module (สารทำความเย็น Freon : R11, R22, R113, R134A, R409A, R410A) MQ-139 (PCB สีเขียว)

MQ139 Freon Sensor Module is used in the gas detector for Freon in house or environment, and they are suitable for detecting of R11, R22, R113, R134A, R409A, R410A

The figure shows the connection of the MQ sensors to the Arduino

Features:

• Module with MQ139 gas sensor and circuitry to enable easy plug and use, just connect power and the module is ready to interface with microcontroller.
• Working voltage: DC 5V
• Comes with power and digital signal LED indicator
• 2-way signal output (analog output, and TTL-level output)
• TTL output valid signal is low; (low output signal light, which can be accessed microcontroller IO port)
• Analog output increases with the concentration, the higher the voltage the higher the concentration with high sensitivity
• With a long life and reliable stability
• Fast response characteristics
• With mounting holes for easy permanent installation
• Main chip: LM393, formaldehyde-sensing probe
• Size: 35mm x 20mm x 28mm
• Weight: 14 g

Packing List:

• 1 x MQ139 Sensor Module

Resources:

• MQ-139 Datasheet
• Example of coding using Arduino by Electropeak: How to Calibrate and Use MQ9 Gas Sensor with Arduino the coding uses MQ9 gas sensor, however for each gas sensor (MQ series) the coding is just the same.
• Example of sensor calibration, by empierre from github, Arduino code.