Target: Refrigerant gas
Model: MP511D
Detection range: 200~10000ppm
Detection principle: Semiconductor
Characteristics: High selectivity, fast response, good anti-interference

MP511D Manual download
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The MP511D Freon gas sensor uses a multilayer thick film manufacturing process to fabricate heating and measuring electrodes and a metal oxide semiconductor gas-sensitive layer on a miniature ceramic substrate, and encapsulate it in a metal casing. When the detected gas exists in the ambient air, the conductivity of the sensor changes. The higher the concentration of the gas, the higher the conductivity of the sensor. This change in conductivity is converted into an output signal corresponding to the gas concentration through the circuit. The product has good anti-interference ability against common gases such as alcohol and acetic acid in usage scenarios.


Used for leak detection of refrigerants in air conditioning and refrigeration systems


  • High selectivity, fast response, good anti-interference, long lifespan, good stability
  • Can detect kinds of refrigerant gases R134a, R454b, R290.


Model MP511D
Sensor Type Semiconductor flat surfaced sensor
Standard Encapsulation Metal Cap
Detection Gas Refrigerant gas
Detection range 200~10000ppm
Standard circuit Loop voltage VC 5.0V±0.1V DC
Heating voltage VH 5.0V±0.1V DC
Load resistance RL Adjustable
sensor features in standard test condition Heating consumption PH ≤350mW
Surface resistance RS 0.5~10KΩ(in 2000ppm R290)
Sensitivity S 0.4~0.6 (R290) Rs(in 3000ppm)/Rs(in 1000ppm)
Standard condition of test Temperature, humidity 25℃±2℃;55%±5%RH
Standard test circuit Vc:5.0V±0.1V;     VH:5.0V±0.1V
Warm-up time 7 days

* The description and specifications might be changed without notice. Please contact us for the latest information before placing orders.

Technical Support:

Customized technical design and function, LOGO and package are available without extra charge (including molding fee) for mass volume.

The sensors don't have sleeping mode. It can be set in program if needed.

All Winsen products go through strict inspections and tests to make sure they are 100% qualified before shipping out.

The sensor has been fully tested (not calibrated) before leaving the factory. However, after transportation and storage, the environment conditions change, and the surface of the sensor absorbs moisture, mixed gas, pollution matters, etc. It is recommended that customers perform aging and calibration after sensors become stable according to the program and use occasions of the whole device.

15﹪-90﹪RH without condensation,greater or less than this range or long-term high temperature and high humidity will affect the life of the sensor.

Our sensors are certified with CE, 3C, ROHS, anti-explosion, fire prevention, and coal mining safety according to different applications. And we provide assistance for new certification.

Many factors can cause the sensor to fail such as broken wires in transportation, poisoning, falling off of the sensitive material, damage to the heating wire (device), etc. Please find specific cause in each category with Winsen’s aftersales.

Winsen provides professional consultation and service before and after sales. We will recommend the best fitting sensor for your demand. If you have any problem, don’t hesitate to email us to

Due to high volume of daily incoming emails and time zone difference, we may not be able to reply your emails immediately. But we will reply to your inquiry in 24 business hours.