ATEX & IEC Certified Explosion Proof Flammable Gas Detection Head

General Description:

The Nemoto NCH-180 is a new low cost catalytic flammable gas sensor fitted within a certified Flameproof enclosure.

Using the popular NAP-56A sensor, the NCH-180 offers the excellent detection performance, stability and long life you may expect from a Nemoto Pellistor Gas Sensor, but may also be used in hazardous locations when coupled with a suitable certified Flameproof Junction Box.

The NCH-180 is remarkably compact compared with other similar Ex certified devices, with the sensor contained within the same barrel as the mounting thread, resulting in a very ergonomically elegant design, mounting flush to the junction box wall.



Detectable Gas:

Detection range:

Voltage supply:

Current drawn:

Minimum Sensitivity:

Zero Offset (20oC):

Response time (90%):


Expected lifetime:

Long Term Span Drift:

Long Term Zero Drift:

All Flammable Gases

0 – 100% LEL

2.5V +/- 0.1V

180mA +/- 20 mA

20mV / % CH4

0mV +/-  30mV

< 30 seconds

+/- 1% LEL

> 5 years

<+/- 8% FSD/ year

<+/- 2mV / year

Operating Conditions:

Operating temperature:

Humidity range:


Mounting Thread


-20 +70oC

0 – 95% RH

0.9 – 1.1 atm

M20 - 1.5mm Pitch

Linear to 60% LEL


  •        Certified Explosion proof (ATEX + IEC)
  •        Measures Flammability directly
  •        Highly resistant to catalyst poisons
  •        Resistant to shocks and vibration
  •        Specific to flammable gases
  •        Unaffected by Humidity
  •        Very simple circuitry
  •        Very low long term drift