Honeywell Sensepoint XCD SPXCDASNNX – Fixed NO₂ Detector (0-50ppm, Electrochemical (Surecell™), ATEX, 316SS, M20)
SPXCDASNNX is the Sensepoint XCD nitrogen dioxide electrochemical transmitter, 0–50 ppm default, 316 stainless steel, 2 × M20, ATEX / IECEx / GB. It is aimed at diesel halls, tunnel plant rooms and nitric-acid fill points.
Same gas, swap enclosure/approval: aluminium SPXCDALMNX, 316SS SPXCDASNNX, UL SPXCDULNNX. SPXCDALMNX · SPXCDASNNX · SPXCDULNNX
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 |
| NX | Gas nitrogen dioxide, Electrochemical (Surecell™) | NX |
Same gas, swap enclosure/approval: aluminium SPXCDALMNX, 316SS SPXCDASNNX, UL SPXCDULNNX.
Technical specifications
| Target gas | NO₂ / nitrogen dioxide |
|---|---|
| Principle | Electrochemical (Surecell™) |
| Default range | 0-50ppm |
| User FSD window | 10-50ppm |
| Resolution | 5ppm |
| Output | 4–20 mA sink/source + optional Modbus RTU |
| Supply | 16–32 VDC (24 VDC nominal) |
| Power | 3.7 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
NO₂ is heavier than air and rides exhaust plumes toward floor trenches. Surecell™ electrochemistry is required; IR and catalytic channels do not quantify NO₂. Mount low on the exhaust side of the engine hall, not on the fresh-air intake.
Sensor and replaceable parts
OEM cartridge SPXCDXSN1SS. Calibration cap S3KCAL. Collecting cone follows buoyancy—see installation. Pipe/duct kits: SPXCDMTBR / SPXCDDMK.
Typical applications
Standby-generator rooms, road-tunnel niches and fertiliser fill bays need a dedicated NO₂ point tied to extract fans. XCD holds that interlock; a badge dosimeter only explains the exposure after the fact.
Selection contrast
| P/N | Gas | Range | Principle |
|---|---|---|---|
| SPXCDASNNX | NO₂ | 0-50ppm | EChem |
| SPXCDASMCX | CO | 0-300ppm | EChem |
| SPXCDASMHX | H₂S | 0-50ppm | EChem |
| SPXCDASMO1 | O₂ | 0-25.0%Vol | EChem |
| SPXCDALMNX | NO₂ | 0-50ppm | EChem |
| SPXCDULNNX | NO₂ | 0-50ppm | EChem |
Installation and wiring
Wall-mount SPXCDASNNX (nitrogen dioxide, 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 SPXCDASNNX. Land SPXCDASNNX 4–20 mA as three-wire and set Modbus address from the menu only. Magnetic wand calibration on the SPXCDASNNX lid stays non-intrusive. SPXCDASNNX NO₂ sits low on the exhaust wall.
FAQ
- What temperature rating does SPXCDASNNX have?
- SPXCDASNNX certified −40 to +65 °C (T6); some T-class to +75 °C. Sensor performance is often −20 to +55 °C.
- Is SPXCDASNNX ATEX or UL certified?
- SPXCDASNNX is the ATEX/IECEx/GB scheme (entries 2 × ¾″ NPT), not a UL housing. Current transmitter ATEX: UL 21 ATEX 2619X.
- What is the power draw of SPXCDASNNX?
- SPXCDASNNX typically draws 3.7 W (CAT 4.9 W, IR/EC 3.7 W, max 5 W). Supply 16–32 VDC (24 VDC nominal).
- What is SPXCDASNNX?
- SPXCDASNNX is a Honeywell Sensepoint XCD complete kit (transmitter + cartridge): nitrogen dioxide, 316 stainless steel, entries 2 × ¾″ NPT, approval ATEX / IECEx / GB. SPXCDASNNX is 4–20 mA and relays; for Modbus order SPXCDASNNXM. SPXCDASNNX is in stock.
- Can I retap SPXCDASNNX from M20 to NPT (or vice versa)?
- No. SPXCDASNNX flameproof entries are machined 2 × ¾″ NPT. Order the matching P/N for the other thread; do not retap in the field.
- How is SPXCDASNNX mounted?
- Wall-mount SPXCDASNNX on the one-piece plate with M8 bolts; pipe Ø40–80 mm uses SPXCDMTBR, duct SPXCDDMK. Glands must match 2 × ¾″ NPT.
- Does SPXCDASNNX provide 4–20 mA?
- SPXCDASNNX outputs 4–20 mA (source/sink). 4–20 mA is the only EN performance safety function.
Documents
Availability and enquiry
Availability: In stock. Quote full P/N SPXCDASNNX, gas/range and approval.