Methane gas protection equipment 9V Deffender SDI, Front view detector Methane gas protection equipment 9V Deffender SDI, Side view detector Methane gas protection equipment 9V Deffender SDI, Right side view detector


The Deffender methane gas detector is ideal for residential environments. Deffender detects methane gas and LPG.

The detector interrupts the methane gas supply by means of the solenoid valve mounted on the gas pipe. This will activate if the gas level rises alarmingly in the range 1% – 10%. Thanks to SMD technology, it offers certain advantages: much fewer errors on the base plate, good performance under vibration conditions, full automation that eliminates many errors, especially human errors.

This detector is also available in the Deffender SDI version (Methane gas protection equipment consisting of detector and solenoid valve).



Deffender Accurate warning
Accurate warning If the gas sensor is not working properly, the detector will emit a short audio signal followed by a four second pause. The red LED will then be lit.
Deffender Dual functionality
Dual functionality Deffender SDI can detect both methane gas and butane gas (LPG). However, depending on which gas you want it to detect, you need to follow the steps in the manual for proper placement.
Deffender Silent function
Silent function When the Deffender SDI detector has triggered the alarm, the audio signal can be turned off by pressing the "Test" button. The piezo siren will be turned off for five minutes. The red LED will flash.


Power supply
230 VAC, 50/60 Hz
Power absorbed
~ 2W
Gas detected
Gas butane (GPL), Gas methane
Alarm level
5% L.E.L.
Sensor type
SnO2 semiconductor
Piezoelectric alarm
85 dB la 1 m
Operating temperature
+ 2 °C ... + 40 °C
10% ... 90% RH (non-condensing)
Protection class
70 x 115 x 44 mm
aprox. 150 gr.
2 years

Frequent questions

How do I mount the Deffender SDI for butane gas detection?
Installation should be done in low places (approx. 30 cm above the floor) because butane gas (LPG) is heavier than air.
How do I install Deffender SDI for methane gas detection?
Installation should be done in high places (approx. 30 cm from the ceiling) because methane gas is lighter than air.
I smell gas, but the detector doesn't respond
The unpleasant and easily recognisable smell (an unpleasant sulphurous odour) of natural gas used in homes is due to odorant additives, such as tert-butylthiol, which are used for safety. Most people can detect this smell at fairly low levels of gas concentration (2% L.I.E. or less), but certain disabilities or advancing age can lead to a reduction in this smell sensitivity. The L.I.E. (Lower Explosive Limit) of the gas defines the minimum volume ratio of combustible gas or vapour in the air in which an explosive atmosphere will form. The detector is calibrated to trigger the alarm at the threshold of 10% of the L.I.E. of the detected gas. Thus, it is possible for a person to smell gas before the alarm is activated. This does not necessarily indicate a fault in the device. For humans, a gradual increase in gas concentration may also go unnoticed due to olfactory fatigue. Translated with (free version)
Wired methane gas detectors


Product code: 3710001
Methane / butane gas detector, 9-12VDC
  • Accurate warning
  • Dual functionality
  • Silent function