top of page
GFG CS21 Refrigerant Gas Detector

GFG CS21 Refrigerant Gas Detector


The transmitter CS21 uses the proven chemosorption principle for detection of toxic and combustible gases and vapours. The extremely short response time of the transmitter enables the user to take action quickly to prevent damage to people and plant. Long sensor life makes the CS21 an economic alternative.


The sensor can often be used continuously for 5 years, before replacement is required. A wide temperature range from -40°C to + 60 °C makes the CS21 useful for a variety of applications, particularly for the protection of refrigeration plants.

The distance between the CS21 transmitter and controller can be more than 500 metres. Sturdy aluminium housing protects the sensor and electronic parts against impact, splash-water and dirt.


The CS21 is not Ex-certified, so may not be used directly in areas containing highly flammable gases. To detect flammable gases and vapours within the zoned area the gas must be advanced to the transmitter. Here, explosion protection must be guaranteed with suitable components, e.g. flame arrestors.

  • Tech Info

    • Gas: see chart
    • Detection range: see chart
    • Gas supply: Diffusion through stainless steel + PTFE membrane
    • Detection principle: Chemosorption (CS)
    • Power supply: 10 .. 32 V DC
    • Output signal: 0,2 .. 1 mA (4kW) or 4 .. 20 mA (200W)
    • Response time: tAlarm less than 14 seconds (depending on gas)
    • Expected sensor life: > 5 years
    • Ambient temperatur: -30°C .. +55°C
    • Humidity: 20 .. 96 % r. h., non-condensing
    • Pressure: 920 .. 1100 hPa
    • Casing material: Aluminium
    • Casing protection: IP54, splash water proof
    • Dimensions: 100 x 100 x 57 mm (WxHxD)
    • Weight: 370 g
    • Cable connection: Shielded cable 3 x 0,75mm2 for up to 500 m, 3 x 1,5 mm2 for more than 500 m PG11 - cable gland
    • Cable: Shielded cable e.g. LiYCY 3x1,5 mm2
  • Downloads

  • Delivery

    We aim to Delivery products with you within 4 weeks of receipt of order. However, in exceptional circumstances delivery may be up to 6 weeks due to manufacturer lead times. Please inform us if you require fast delivery as we will do our utmost to expedite your order.

  • Quantity Orders

    Please contact us directly to discuss quantity purchases and additional discounts.  We will subsequently provide you with a formal quote with the applied discount, which will be valid for 30 days 

  • Hire

    Many of the products you have seen are available for hire, so feel free to contact us if you would prefer to hire this instrument.

bottom of page