Honeywell Sensepoint XCD SPXCDASMFX – Fixed LEL Detector (0-100%LEL, Catalytic bead (poison-resistant), ATEX, 316SS, M20)
SPXCDASMFX is the catalytic-bead LEL transmitter on Sensepoint XCD, 0–100 %LEL default, 316 stainless steel, 2 × M20, ATEX / IECEx / GB. Choose it for general hydrocarbons where infrared windows would fog or the budget cannot justify dual-beam IR.
Same gas, swap enclosure/approval: aluminium SPXCDALMFX, 316SS SPXCDASMFX, UL SPXCDULNFX. SPXCDALMFX · SPXCDASMFX · SPXCDULNFX
Part-number decode
| Segment | Meaning | This SKU |
|---|---|---|
| SPXCD | Sensepoint XCD series | SPXCD |
| A / U | Approval A=ATEX/IECEx/GB; U=UL | A |
| L / S | Enclosure L=LM25 aluminium; S=316SS | S |
| M / N | Entry M=M20; N=3/4" NPT | M |
| FX | Gas flammable gas (catalytic), Catalytic bead (poison-resistant) | FX |
Same gas, swap enclosure/approval: aluminium SPXCDALMFX, 316SS SPXCDASMFX, UL SPXCDULNFX.
Technical specifications
| Target gas | LEL / flammable gas (catalytic) |
|---|---|
| Principle | Catalytic bead (poison-resistant) |
| Default range | 0-100%LEL |
| User FSD window | 20-100%LEL |
| Resolution | 10%LEL |
| Output | 4–20 mA sink/source + optional Modbus RTU |
| Supply | 16–32 VDC (24 VDC nominal) |
| Power | 4.9 W |
| Enclosure | 316 stainless steel |
| Entries | 2 × M20 |
| Display | Tri-colour backlight LCD |
| Relays | 3×5A@250VAC |
| Ingress | IP66 |
| Approvals | ATEX / IECEx / GB |
| Temperature | −40~+65 ℃ |
| Mass | approx. 3.1 kg (6.8 lb) |
Why this principle for this gas
A poison-resistant pellistor sees the heat of combustion and therefore works on a wide hydrocarbon mix, including species IR filters miss. It is not a toxic detector. Mount above potential release points for gases lighter than air and below for heavier vapours; keep silicone sealants and leaded petrol away from the sinter.
Sensor and replaceable parts
OEM cartridge SPXCDXSFXSS. Calibration cap S3KCAL. Collecting cone follows buoyancy—see installation. Pipe/duct kits: SPXCDMTBR / SPXCDDMK.
Typical applications
Pump rooms, filling gantries and compressor packages still standardise on catalytic LEL because the gas slate is mixed. XCD locks the 4–20 mA into the ESD matrix and allows magnetic bump test without a hot-work permit to open the lid.
Selection contrast
| P/N | Gas | Range | Principle |
|---|---|---|---|
| SPXCDASMFX | LEL | 0-100%LEL | Catalytic bead |
| SPXCDASMRX | CH₄ | 0-100%LEL | IR |
| SPXCDASMPX | C₃H₈ | 0-100%LEL | IR |
| SPXCDASMHX | H₂S | 0-50ppm | EChem |
| SPXCDALMFX | LEL | 0-100%LEL | Catalytic bead |
| SPXCDULNFX | LEL | 0-100%LEL | Catalytic bead |
Installation and wiring
Wall-mount SPXCDASMFX (flammable gas (catalytic), 316 stainless steel) through the one-piece plate with M8 bolts sized for that mass. This SKU uses 2 × M20 entries: pipe kit SPXCDMTBR covers Ø1.5–3″, duct kit is SPXCDDMK, and glands must match—do not retap SPXCDASMFX. Land SPXCDASMFX 4–20 mA as three-wire and set Modbus address from the menu only. Magnetic wand calibration on the SPXCDASMFX lid stays non-intrusive. Keep silicones off the SPXCDASMFX pellistor; light hydrocarbons high, heavy vapours low.
FAQ
- SPXCDASMFX: Will silicone vapours kill this LEL bead?
- SPXCDASMFX — Yes, silicones and chlorinated solvents poison pellistors. Specify the IR methane or propane SKU if those contaminants are routine.
- SPXCDASMFX: What bump-test gas should I use?
- SPXCDASMFX — Use the target hydrocarbon at 50 %LEL. Methane-only test gas will under-state response if the process is petrol vapour.
- What weight penalty does 316SS add on SPXCDASMFX?
- SPXCDASMFX is ~6.8 lb versus ~4.4 lb for aluminium sibling SPXCDALMFX. The extra mass buys chloride resistance for this flammable gas (catalytic) point; keep M8 wall bolts at the stamped size.
- Can I convert SPXCDASMFX from ATEX M20 to NPT in the field?
- No. SPXCDASMFX flameproof entries are machined M20. North-American NPT is UL sibling SPXCDULNFX, not an adaptor on this ATEX flammable gas (catalytic) body.
- Can I retrofit Modbus on SPXCDASMFX after it ships?
- Modbus RTU on SPXCDASMFX is a transmitter sales option, not a jumper on the flammable gas (catalytic) lid. Confirm the option before the box leaves; 4–20 mA sink/source is already on this SKU.
Documents
Honeywell Sensepoint XCD datasheet / manual · On-site XCD selection matrix
Availability and enquiry
Stock is lot-based. If this aluminium ATEX box is out, jump to 316SS SPXCDASMFX or UL SPXCDULNFX rather than a dead SKU.