Non-intrusive calibration

  • Calibration can be performed locally without the need for hot work permits – minimises operational down-time
  • Local display and buttons enable calibration without opening the junction box

Flexible output options

  • 4-20mA current sink – works with a wide selection of control panels
  • 2 wire format

Rugged and reliable

  • Made from tough carbon loaded nylon
  • Ingress protection to IP65 as standard

Low cost of ownership

  • Non-intrusive one man calibration – easy to operate and maintain
  • Long life sensors – keeps interuption to on-site activity to a minimum
  • Simple parts replacement

Wide range of sensors

  • Extensive range of electrochemical sensors for oxygen and toxic gas detection


Size160 x 123 x 92mm
(6.3 x 4.8 x 4.5ins)
Weight0.7kg (1.5lbs)
Ingress protectionIP65
Enclosure materialJunction box: Carbon loaded nylon
Sensor housing: ABD Plastic
Power8-32Vdc, 4-20mA loop-powered
Cable entries1 x M20 or 1/2” NPT with adaptor
Operating temperature-20°C to +55°C (-4°F to 132°F) *
Humidity15 to 90% RH non-condensing
Display2-Line, 16 character LCD
Calibration methodVia push-buttons
Electrical output2 wire 4-20mA sink
TerminalsSuitable for up to 2.5mm2 cable
Sensor typeElectrochemical
Repeatability+/- 2% FSD typically
Zero drift+/- 2% FSD, 6 months typically
Response timeContact Crowcon for a full list of sensor response times
PerformanceTested in accordance with EN60079-29-1
Hazardous area zonesZone 0, 1 or 2
Division 1 or 2
(when connected via an isolation device)
ApprovalsEx II 1 G Ex ia IIC T4 (-40°C to +65°C)
Exia IIC T4 Gb Tamb -20°C to +55°C
UL Class I, groups A, B, C and D
EMC complianceEN 50270, FCC: CFR 47 Part 15, ICES-003

* Figures shown exclude the sensors – Please contact Crowcon for a full list of sensor operating temperatures


Gases and Ranges

GasRange Available
Ammonia (NH3)50, 100, 1000ppm
Chlorine (Cl2)5, 10, 20ppm
Carbon monoxide (CO)250, 500ppm
Chlorine dioxide (ClO2)1ppm
Hydrogen (H2)2000ppm, 50% LEL, 100% LEL
Hydrogen cyanide (HCN)25ppm
Hydrogen sulphide (H2S)25, 50, 100, 200ppm
Hydrogen fluoride (HF)10ppm
Nitrogen dioxide (NO2)10ppm
Oxygen (O2)25% vol.
Ozone (O3)1ppm
Phosgene (COCl2)1ppm
Phosphine (PH3)2ppm
Sulphur dioxide (SO2)10, 20, 30ppm


Below is a small selection of the accessories available for the TXgard-IS+.

Spray deflector


For outdoor installations and protection from water sprays, for example in water treatment or food processing plants. Includes accessory adaptor. (not suitable for use with Xgard Type 4)

Flow adaptor


For applications where gas is being sampled via a pipe or tube.

Stainless steel duct mounting plate


For GRP junction boxes. Maximum duct airflow: 6 metres per second. Use TXgard-IS+ detector with side-entry.

Calibration adaptor


To enable calibration gas to be applied to the detector. One adaptor can be used for several detectors.

Cable gland


M20 Nylon. Fits Txgard-IS cable entries.