Low-Cost Flammable Catalytic Gas Sensor for LPG/Propane/Butane

General Description:

The Nemoto NAP-67A is the version of the NAP-56A which is optimised for the detection of higher hydrocarbons such as LPG, Propane, Butane, Gasoline vapours etc.


It should not be used if the sensor is required to detect methane or natural gas, because its signal level on Natural gas is very small. But its signal for gases such as LPG is significantly higher than that of the NAP-55A. Internally closely related to the NAP-66A, the NAP-67A benefits from a slightly higher signal output and a wider temperature range which makes the NAP-67A particularly useful in Instruments designed for the detection of  LPG leaks Caravans and other Recreational Vehicles.




Detectable Gas:

Detection range:

Voltage supply:

Current drawn:

Typical Sensitivity:

Zero Offset (20oC):

Response time (90%):


Expected lifetime:

Long Term Span Drift:

Long Term Zero Drift:


0 – 60% LEL

2.0V +/- 0.2V

160mA +/- 10 mA

20mV / 0.2% C4H10

0mV +/-  35mV

< 10seconds

+/- 1% LEL

> 3 years

<+/- 2% FSD/ month

<+/- 2mV / year

Operating Conditions:

Operating temperature:

Humidity range:


Temperature Drift (zero):


-30 +70 oC

0 – 95% RH

0.9 – 1.1 atm

<+/- 2% LEL

Linear to

60% LEL


  •        Measures flammability directly
  •        Highly resistant to Catalyst poisons
  •        Wide Ambient Temperature Range
  •        Effectively Linear output to 50%LEL
  •        High Signal Output to LPG Gases
  •        Unaffected by Humidity
  •        Very Simple circuitry
  •        Very Low Long term drift