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NH3-AF Alphasense 50ppm Ammonia Gas Sensor

NH3-AF Alphasense 50ppm Ammonia Gas Sensor
Regular price $185.00

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The NH3-AF Alphasense Ammonia Gas Sensor is designed to detect higher concentrations of ammonia gases across multiple industries.

It is designed for lower level detection across 50ppm ammonia concentrations. This sensor is also designed for ease of integration in refrigerant environments, as well as food and beverage, HVAC, laboratories, and safety applications. 

Set by OSHA, the Permissible Exposure Limit for ammonia is 50 parts per million (ppm) averaged over an eight-hour workday. The NIOSH Recommended Exposure Limit (REL) for ammonia is 25 ppm averaged over an eight-hour workday. NIOSH also defines a Short-Term Exposure Limit (STEL) of 35 ppm during any 15-minute period in the day. 

Ammonia gas sensors are commonly used for personal protection in hazardous gas environments to ensure indoor air quality is safe and gaseous ammonia levels have not exceeded safety thresholds during industrial processes.


  • Accurate, Quality EC sensor 0-50ppm
  • Meets OSHA Permissible Exposure Limits
  • Low Cross-Sensitivity across multiple gases
  • Easy to use and integrate into portable gas detectors
  • No external power required, low maintenance
  • Proven and trusted design - 90 day warranty


  • Sensitivity: nA/ppm in 50ppm NH3 15 to 40
  • Response time: t90 (s) from zero to 50ppm NH3 (300 seconds) <150
  • Zero current: ppm equivalent in zero air < ±10
  • Range: ppm NH3 limit of performance warranty 100
  • Linearity: ppm error at full scale, linear at zero and 40ppm NH3 +5 to -5
  • Overgas limit: maximum ppm for stable response to gas pulse
  • Zero drift: ppm equivalent change/year in lab air < 2
  • Sensitivity drift: % change/year in lab air, monthly test < 3
  • Operating life: months until 80% original signal (24 month warranted) > 24
  • Sensitivity@ -20°C % (output@ -20°C/output@ 20°C) @50ppm 100 to 110
  • Sensitivity@ 50°C % (output@ 50°C/output@ 20°c) @50ppm 100 to 110
  • Zero@ -20°C ppm equivalent change from 20°c | -10 to -0
  • Zero@ 50°C ppm equivalent change from 20°c | 5 to 20
  • Temperature range °C: -30 to 50
  • Pressure range kPa: 80 to 120
  • Humidity range %RH continuous 15 to 90
  • Storage period months: @ 3 to 20°c (stored in sealed pot) 6
  • Load resistor: olms (recommended) 10 to 47
  • Weight grams: < 6
  • H2S sensitivity % measured gas@ 20ppm H2S  < ±3
  • H2 sensitivity % measured gas@ 400ppm H2@ 20°C < 15
  • NO2 sensitivity % measured gas@ 20ppm NO2 < -60
  • Cl2 sensitivity % measured gas@ 10ppm Cl2 < -300
  • NO sensitivity % measured gas@ 50ppm NO < 20
  • SO2 sensitivity % measured gas@ 20ppm SO2 nd
  • C2H4 sensitivity % measured gas@ 400ppm C2H4 <2


    • 90 Days - See CO2Meter Terms and Conditions

    Tube cap adapters easily convert 20mm standard gas sensors from diffusion to sampling sensors. Molded polymer grips sensor for easy fit and removal while maintaining a good seal.

    Micro-Pump Kit includes all the tools you need to urilize the tube-cap adapters as part of a sampling sensor system.

    Nafion tubing is a highly selective, semi-permeable membrane to water vapor. If gases inside Nafion tubing are wetter than gases surrounding the tubing, drying will occur. If the surrounding gases are wetter, humidification will occur.

    Micro gas sampling pumps provide a constant flow of air across the sensor with a tube cap - perfect for bench-top testing of sensors for closed-loop sampling applications.

    Sensor Pin Sockets - Manufacturers do not recommend soldering to the pins. Pin sockets can be purchased from Andon distributors. Click here to search for your sensor's socket. Select the brand PDF, find your sensor, then search for the Andon part number for your sensor's socket.

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    Customer Reviews

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    "Easy to install, easy to set up, and easy calibration - just what I was looking for."

    - Phillip Farrar
    Water Plant Superintendent

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