Crowcon TXgard-IS+ Fixed Gas Detector

Crowcon TXgard-IS+ Fixed Gas Detector

The Crowcon TXgard-IS+ is a Intrinsically Safe (I.S.) toxic and oxygen gas detector with local LCD display. A very wide choice of sensors are available for use in a variety of applications. TXgard-IS+ is ATEX certified for use in Zone 0,1 or 2 hazardous areas and also UL and cUL certified for use in Division 1 or 2 hazardous areas.


  • 4-20mA current sink – works with a wide selection of control panels
  • 2 wire format
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Please note - Product designs and specifications are subject to change without notice. The user is responsible for determining the suitability of this product.

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 toxic gases and oxygen


Size 160 x 123 x 92mm
(6.3 x 4.8 x 4.5ins)
Weight 0.7kg (1.5lbs)
Ingress protection IP65
Enclosure material Junction box: Carbon loaded nylon
Sensor housing: ABD Plastic
Power 8-32Vdc, 4-20mA loop-powered
Cable entries 1 x M20 or 1/2” NPT with adaptor
Operating temperature -20°C to +55°C (-4°F to 132°F) *
Humidity 15 to 90% RH non-condensing
Display 2-Line, 16 character LCD
Calibration method Via push-buttons
Electrical output 2 wire 4-20mA sink
Terminals Suitable for up to 2.5mm2 cable
Sensor type Electrochemical
Repeatability +/- 2% FSD typically
Zero drift +/- 2% FSD, 6 months typically
Response time Contact Crowcon for a full list of sensor response times
Performance Tested in accordance with EN60079-29-1
Hazardous area zones Zone 0, 1 or 2
Division 1 or 2
(when connected via an isolation device)
Approvals Ex 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 compliance EN 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

Gas Range 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

TXgard-IS+ Accessories

C01338 Spray deflector. For outdoor installations & protection from water sprays.
C01339 Flow adaptor, for use in sampling applications.
00027D Stainless steel duct mounting plate - for GRP junction boxes. Maximum duct airflow: 6 metres per second. Use TXgard-IS+ detector with side-entry.
C03005 Calibration adaptor
M02025 Cable gland M20 Nylon.

TXgard-IS & TXgard-IS+ Spare Sensor Assemblies

S011185 NH3 (Sensoric), 0-1000 ppm (-20C min.): for TXgard-IS, IS+
S01730 NH3 (Sensoric), 0-50 ppm (-20C min): for TXgard-IS, IS+
S01181 NH3 (Bionics), sensor assembly: for TXgard-IS
C01187 NH3 (Bionics), sensor electrolyte: for TXgard-IS
M02096 NH3 (Bionics), sensor membrane: for TXgard-IS
S01984 B2 (Sensoric): for TXgard-IS
S01872 B2 (Bionics): for TXgard-IS
491/1 B2 (Bionics) sensor electrolyte: for TXgard-IS
S01171 CO (City): for TXgard-IS, IS+
S01182 CL2 (City): for TXgard-IS, IS+ 0-20ppm only)
S011189 CL2 (Sensoric): for TXgard-IS, IS+ (0-5, 10ppm )
S01900 CLO2 (City): for TXgard-IS
S01642 ETO (City): for TXgard-IS
S01187 F2 (Bionics): for TXgard-IS
C01235 F2 (Bionics) sensor electrolyte: for TXgard-IS
M02196 F2 (Bionics) sensor membrane: for TXgard-IS
S01728 HCL (Sensoric): for TXgard-IS
S01178 HCN (City): for TXgard-IS
S01729 HCN (Sensoric): for TXgard-IS, IS+
S01983 HF (Sensoric): for TXgard-IS, IS+
S01188 HF (Bionics): for TXgard-IS
M02197 HF (Bionics) membrane: for TXgard-IS
C01236 HF (Bionics) sensor electrolyte: for TXgard-IS
S01176 H2/Hi (City 3-Series) Hi: for TXgard-IS, IS+
S01177 H2/Lo (City 7-Series) Lo: for TXgard-IS, IS+
S013000 H2 3E 4%, 0-100% LEL: for TXgard-IS+
S01170 H2S (7H sensor): for TXgard-IS, IS+
S01174 NO (City): for TXgard-IS
S01175 NO2 (City): for TXgard-IS, IS+
S01169 O2 (C/2): for TXgard-IS, IS+
S012028 O2 (7OX-V): for TXgard-IS+ 2009 onwards
S01186 O3 (City) (Citi): for TXgard-IS
S011201 O3 (Sensoric) (Sensoric): for TXgard-IS+
S01640 PH3 (City): for TXgard-IS, IS+
S011987 SiH4: for TXgard-IS
S01172 SO2: for TXgard-IS, IS+
S011226 SO2 - hydrogen immune: for TXgard-IS
S01641 VO (City): for TXgard-IS
S01343 Bayonet sensor housing for 3-pin 32mm diameter sensors: for TXgard-IS, IS+

TXgard-IS+ Spares

S01999/S Personality module for general toxic versions
S011160/S Personality module for ozone or chlorine detectors
S011161/S Personality module for hydrogen cyanide or phosgene detectors
S01997/S Personality module for oxygen detectors (1 year C/2 sensor)
S011007 Terminal PCB (Base board)
S011051 Terminal PCB (Base board)
S011050 Main/Display PCB
S012126/S Personality module for general toxic versions (Non Biased)
S012127/S Personality module for ozone or chlorine detectors (Non Biased)
S012128/S Personality module for hydrogen cyanide or phosgene detectors (Non Biased)
S011052/S Personality module for oxygen detectors (2 year 7OX-V sensor)
S011224 Terminal PCB (Base board)
S011223 Main/Display PCB
E01755 Front panel display/membrane label
M07214 Installation, Operating and Maintenance Manual

TXgard-IS+ I.S. Toxic and Oxygen Gas Detector With Display

TIP-01 carbon monoxide 0-250ppm , M20, top entry, ATEX/IECEx
TIP-02 carbon monoxide 0-500ppm , M20, top entry, ATEX/IECEx
TIP-03 chlorine 0-5ppm , M20, top entry, ATEX/IECEx
TIP-04 hydrogen sulphide 0-25ppm , M20 , top entry, ATEX/IECEx
TIP-05 hydrogen sulphide 0-50ppm , M20 , top entry, ATEX/IECEx
TIP-06 hydrogen sulphide 0-100ppm , M20 , top entry, ATEX/IECEx
TIP-07 oxygen 0-25% Vol. , M20, top entry, ATEX/IECEx
TIP-08 ozone 0-1ppm , M20, top entry, ATEX/IECEx