Crowcon Xgard Fixed Gas Detector Series
Fixed detector family for oxygen, combustible and toxic gases using multiple sensors and enclosure technologies.
Original manufacturer: Crowcon; listed through Prosense as a distributor where applicable.
VARIANT DEPENDENT: flameproof (Ex d), intrinsically safe (Ex i), and safe-area versions exist. Do NOT label the whole series Ex-proof.
Only certified ordering codes are suitable for hazardous locations. Confirm manufacturer’s original ATEX/IECEx certificates, exact gas group, temperature class and installation manual.
Official Technical Source
Crowcon product documentation and approval downloads →
Xgard — select actual sensor technology first
The Xgard name covers more than one physical detection principle and enclosure class. Choose the appropriate oxygen, toxic or combustible gas sensor and its needed field calibration before selecting the transmitter housing. An intrinsically safe build, a flameproof build and a safe-area version have different wiring and approved installation requirements; assigning one family-wide Ex mark would be wrong. Compare output, maintenance, replacement-head compatibility and barrier/gland requirements against the exact Xgard type.
Xgard — do not mix six hardware sensor types — manufacturer technical specification review
Crowcon’s exact product model and options determine gas range, electrical interface, battery, field application and instrument safety certification. Ratings below are not a universal family promise.
| Attribute | OEM model data | Selection consequence |
|---|---|---|
| Type 1 | Electrochemical toxic/O₂; two-wire 4–20 mA current sink; 11–30 V DC | Intrinsic-safety wiring/isolator differs from flameproof catalytic units. |
| Type 2 | Catalytic-bead flammable sensing with three-wire mV bridge | Requires compatible controller bridge excitation and calibration. |
| Type 3 / 4 / 5 | Different catalytic-bead / transmitter arrangements; gas/housing and analog outputs vary | A 4–20 mA type cannot automatically substitute for an mV-bridge head. |
| Type 6 | Thermal-conductivity measuring cell for selected high combustible gas-volume ranges | Gas-mixture and oxygen assumptions differ from a pellistor %LEL sensor. |
| Gas span selection | Type-specific toxic ppm, oxygen %vol and flammable %LEL ranges | No universal CO₂, toxic and flammable calibration with one interchangeable chip. |
| Materials / ambient | Aluminum or 316 stainless options; IP ratings/type enclosure vary | Do not assert IP65, Zone 1 or one T class for every Xgard Type. |
| Certificate basis | ATEX/IECEx schedules differ for Type 1 intrinsically safe and flameproof Types 2–6 | Current approved barrier, glands, sensor and cable entries must be checked for each type. |
Commissioning and risk limits
The word ‘Xgard’ refers to multiple physical detector families. Correct procurement begins with target gas, ppm/%LEL/%vol span, electrochemical versus pellistor versus thermal-conductivity principle, output type and hazardous-area classification. A Type 2 mV detector tied to a specific Crowcon controller is not a universal 4–20 mA industrial transmitter. Proof-test at the actual detector head, commission alarm/fault response and preserve the original approval scope when replacing sensing elements.
Primary technical source: Crowcon original product data, approvals and model resource library. Exact gas-specific detector, current order code and Ex/IECEx schedule must be checked against supplied hardware.
Independent AirAlign technical editorial assessment · 25 October 2026. Information is not a stand-alone Ex/SIL or occupational safety certificate.