Gas leak sensor: Reliable detection of flammable gases
€102.90
The Gas Detector for Combustible Gases with Relay Output
The HW group Gas Leak Detector (GS-133) indicates the leakage of combustible gases. The sensor detects all types of combustible gases, e.g. natural gas, town gas, propane, bottled gas, acetylene or hydrogen, and offers two selectable reactions depending on the gas concentration.
The detector is characterized by high stability, high sensitivity, long service life and compact dimensions. A gas leak is signaled optically (LED), acoustically (buzzer) and via a relay output with configurable function. A 12 V DC power supply is required for operation.
Reliably Detect and Report Gas Leaks
The Gas Leak Detector detects two concentration levels and triggers different reactions depending on the setting.
All Combustible Gases
Detects natural gas, town gas, propane, bottled gas, acetylene, hydrogen and other combustible gases.
Two Alarm Levels
Two selectable reactions depending on gas concentration: 1st level with short, 2nd level with long signal tones.
Optical and Acoustic
Red LEDs for both alarm levels and a buzzer with 94 dB at 0.3 m distance.
Potential-Free Relay Output
Changeover contact (C, NO, NC) for 230 V AC / 5 A, optionally triggering at the 1st or 2nd level.
Alarm Memory
Selectable via jumper: The alarm remains until the power supply is briefly disconnected.
Fast Response
Response time of 20 s with compact dimensions of 100 x 74 x 39 mm.
How the Gas Leak Detector Is Constructed
The detector is a compact wall-mounted device (100 x 74 x 39 mm, 112 g) with sensor element, indicators, buzzer, relay and connection terminals.
Sensor Element with Protective Grid
A hot platinum filament is used as the measuring principle. The housing grids must not be clogged with dust so that air can reach the sensor unhindered.
Green LED (Operating Indicator)
Off: detector is switched off. Flashing: warm-up phase. Continuously lit: ready for gas alarm. If it flashes alternately with the red LED II, there is a sensor fault.
Red LED I
Lights when the 1st level of gas concentration is reached.
Red LED II
Lights when the 2nd level of gas concentration is reached.
Buzzer
Emits short signal tones at the 1st level and long signal tones at the 2nd level. The sound level is 94 dB at 0.3 m distance.
Relay Output (Terminal Block)
Potential-free contact with the connections C (common contact), NO (normally open) and NC (normally closed). Switching capacity maximum 230 V AC / 5 A.
Jumper REL
Open: The relay switches when the 1st level is reached. Closed: The relay switches when the 2nd level is reached.
Jumper MEM
Open (factory setting): Alarm memory deactivated. Closed: Alarm memory active.
Power Supply (Terminal Block)
Connection is made via a terminal block with 12 V DC (±20 %). Current consumption is 100 mA, 150 mA with activated relay.
Sequence from Commissioning to Alarm
After switching on, the detector goes through a warm-up phase and then reports its operational readiness.
- After switching on, the green LED flashes, the detector warms up (warm-up time approximately 90 s)
- When the green LED lights continuously, the detector is ready
- 1st level reached: short signal tones, red LED I lights
- 2nd level reached: long signal tones, red LED II lights
- The relay reacts depending on the setting of the REL jumper
- Without alarm memory, the alarm signal ends as soon as the gas concentration returns to normal values
- With closed MEM jumper, the alarm indication remains until the power supply is briefly disconnected
Mounting and Operating Conditions
Installation should be carried out by a specialist installer. The detector is intended for non-hazardous areas, e.g. apartments, living rooms, commercial premises or boiler rooms with gas boilers.
- Mounting on the wall (alternatively tabletop installation)
- Lighter than air (natural gas, town gas, etc.): mount near the ceiling (max. 15 cm below) or directly on the ceiling, at the location where a gas leak is expected
- Heavier than air (propane, butane, etc.): mount near the floor or at the lowest point of the room
- Do not mount near obstacles that impede natural air circulation
- Selection, installation and use according to EN 50244 and EN 60079-29-2 recommended
- Operating environment: −10 °C to +40 °C, 25–75 % RH, indoor use only
- Storage environment: −20 °C to +50 °C, 5–95 % RH
- Protection class IP33
- Designed for normal atmospheric pressure of 86 to 106 kPa
- Use in industrial, SoHo and IT environments
Response Thresholds by Gas Type
The thresholds of the two alarm levels in percent of the lower explosive limit (LEL) and in vol.-%.
| Gas | 1st Level | 2nd Level |
|---|---|---|
| Methane | 10 ± 3 % LEL (0.44 vol.-%) | 18 ± 3 % LEL (0.80 vol.-%) |
| Propane | 18 ± 3 % LEL (0.30 vol.-%) | 30 ± 3 % LEL (0.50 vol.-%) |
| Isobutane | 23 ± 3 % LEL (0.30 vol.-%) | 40 ± 3 % LEL (0.50 vol.-%) |
| Hydrogen | 9 ± 3 % LEL (0.36 vol.-%) | 16 ± 3 % LEL (0.66 vol.-%) |
LEL = lower explosive limit (100 %) according to EN 60079-20-1: methane 4.4 vol.-%, propane 1.7 vol.-%, isobutane 1.3 vol.-%, hydrogen 4.1 vol.-%. Calibrated with isobutane.
Relay Output and Power Supply
The potential-free relay contact can control external devices, such as an automatic gas valve closer, an alarm system or other warning systems.
- Contacts: C (common), NO (normally open), NC (normally closed)
- Relay output max. 230 V AC / 5 A, 1 output
- REL jumper open: Relay switches at the 1st level
- REL jumper closed: Relay switches at the 2nd level
- Power supply 12 V DC ± 20 % via terminal block
- Current consumption 100 mA (150 mA with activated relay)
- Suitable accessories according to the manufacturer: 12V/1.5A Wall plug adaptor INT (international plug-in power supply with three interchangeable plugs)
- Suitable accessories according to the manufacturer: Power jack cable 1m (cable for converting barrel plug to two wires)
- Suitable accessories according to the manufacturer: PowerStripDC (distributes 12 V DC to further devices)
Connection to Perseus, STE2, Ares, Damocles2 and Poseidon2
The Gas Leak Detector provides a potential-free contact (switching value 0/1) and can be connected to the following HW group devices.
- Perseus Industrial 300, 310 and 315
- Perseus Energy 242 and 285
- Perseus Monitoring 140, 145, 150 and 155
- STE2 PLUS, STE2 PLUS SMS-GW and STE2 R2
- Ares 12 LTE and HWg-Ares 12
- Damocles2 MINI, 1208 and 2404
- Poseidon2 3268 and 3468
- HWg-STE plus
- NB-2xIn for IoT monitoring
Check and Maintain the Device
- Keep the detector clean; the grids must not be blocked by dust
- Test with a gas lighter without flame: The detector reacts within 15 seconds
- Professional recalibration at least once a year, details from the dealer
- After use, return to dealer or manufacturer recommended
Behavior in Case of Gas Alarm
In the event of a gas alarm, remain calm and act as follows: do not operate any switches, do not use a telephone at the site of the gas leak, open windows, stop the gas leak if possible or leave the location and call the gas supply company.
Commissioning in a Few Steps
- Select mounting location: for light gases near the ceiling, for heavy gases near the floor
- Mount the detector on the wall without impeding air circulation
- Set the REL jumper (relay at 1st or 2nd level) and MEM jumper (alarm memory) as required
- Optional: Connect the relay output (C, NO, NC) to a gas valve closer, alarm system or HW group device
- Connect the 12 V DC power supply
- Wait for the warm-up phase until the green LED lights continuously
- Test the function with a gas lighter without flame
Why the Gas Leak Detector Is the Right Choice
Broad Gas Detection
Detects all types of combustible gases.
Two Alarm Levels
Different reactions depending on gas concentration.
Flexible Relay
Switches optionally at the 1st or 2nd level, 230 V / 5 A.
Alarm Memory
Activatable via jumper.
Compact
100 x 74 x 39 mm at only 112 g.
24-Month Warranty
According to the manufacturer.
Typical Areas of Use
- Gas leak monitoring in industrial and building areas
- Apartments and living rooms
- Commercial premises
- Boiler rooms with gas boilers
- Control of an automatic gas valve closer
- Triggering an alarm system or other warning systems
Frequently Asked Questions
What is the Gas Leak Detector and what is it used for?
The HW group Gas Leak Detector (GS-133) indicates the leakage of combustible gases, e.g. natural gas, town gas, propane, bottled gas, acetylene or hydrogen. It is used for gas leak monitoring in industrial and building areas and signals optically, acoustically and via a relay output.
Are there options or variants?
No, the Gas Leak Detector is offered without variants.
Which gases does the detector detect?
The sensor detects all types of combustible gases, e.g. natural gas, town gas, propane, bottled gas, acetylene and hydrogen. The response thresholds are specified in the specification for methane, propane, isobutane and hydrogen.
What do the two alarm levels mean?
At the 1st level, short signal tones sound and the red LED I lights. At the 2nd level, long signal tones sound and the red LED II lights. The relay reacts depending on the setting of the REL jumper.
How do I set at which level the relay switches?
Via the REL jumper: If it is open, the relay switches when the 1st level is reached. If it is closed, it switches when the 2nd level is reached.
What does the alarm memory do?
By factory default, the alarm memory is deactivated; the alarm then ends as soon as the gas concentration returns to normal. If the MEM jumper is closed, a triggered alarm remains until the power supply is briefly disconnected.
Where should the detector be mounted?
For gases lighter than air (e.g. natural gas), near the ceiling, maximum 15 cm below, or directly on the ceiling. For heavier gases (e.g. propane, butane), near the floor or at the lowest point of the room. It must not be placed next to obstacles that impede air circulation.
May the detector be used in hazardous areas?
No. The detector is intended for non-hazardous areas, e.g. apartments, living rooms, commercial premises or boiler rooms with gas boilers.
How can I test the function?
With a gas lighter without flame. The detector reacts within 15 seconds. In addition, the detector should be professionally recalibrated at least once a year.
What does it mean if the green and red LEDs flash alternately?
The alternating flashing of the green LED and the red LED II indicates a sensor fault.
What power supply is required?
The detector requires 12 V DC (±20 %) and draws 100 mA, 150 mA with activated relay. Connection is made via a terminal block.
Which devices are compatible?
According to the manufacturer, Perseus (Industrial, Energy, Monitoring), STE2 (PLUS, PLUS SMS-GW, R2), Ares (Ares 12 LTE, HWg-Ares 12), Damocles2 (MINI, 1208, 2404), Poseidon2 (3268, 3468), HWg-STE plus and NB-2xIn are listed.
Questions about the Gas Leak Detector?
Our support team in Germany provides free advice on selection, sensors and configuration.
Product Features:
- Gas leak detector for combustible gases (natural gas, methane, propane, butane, hydrogen)
- Two gas concentration levels with different output signals
- High reliability and sensitivity
- Compact design with long-term stability and lifespan
- For non-explosive areas (apartments, commercial spaces, gas boiler rooms)
Sensitivity (LEL Values):
- Methane: Level 1: 10±3% LEL (0.44% vol.), Level 2: 18±3% LEL (0.80% vol.)
- Propane: Level 1: 18±3% LEL (0.30% vol.), Level 2: 30±3% LEL (0.50% vol.)
- Iso-butane: Level 1: 23±3% LEL (0.30% vol.), Level 2: 40±3% LEL (0.50% vol.)
- Hydrogen: Level 1: 9±3% LEL (0.36% vol.), Level 2: 16±3% LEL (0.66% vol.)
Electrical Data:
- Power supply: 12 V DC ±20%
- Current consumption: 100 mA (150 mA with relay activated)
- Detection method: Hot platinum filament
- Buzzer sound level: 94 dB / 0.3 m
Outputs:
- Relay output: Optional for 1st or 2nd level
- Contact rating: max. 230 V AC / 5 A
- Dry contact: C (Common), NO (Normally Open), NC (Normally Closed)
- Alarm memory: selectable via MEM jumper
Response Times:
- Response time: 20 s
- Warm-up time: approx. 90 s (60 s green LED blinks)
- Test reaction: within 15 seconds
Environmental Conditions:
- Operating environment: Indoor, -10 to +40°C
- Protection class: IP30
- Operating humidity: max. 80%
- Atmospheric pressure: 86 to 106 kPa
Indicators and Controls:
- Green LED: OFF (detector off), Blinking (warming up), ON (ready)
- Red LED I: ON at 1st gas concentration level
- Red LED II: ON at 2nd gas concentration level
- Alternating blinking: sensor error
- Acoustic signal: Short beeps (1st level), Long beeps (2nd level)
Installation:
- Installation only by qualified personnel
- Lighter gases (natural gas): max. 15 cm below the ceiling or directly on the ceiling
- Heavier gases (propane, butane): near the floor or at the lowest point of the room
- No obstacles to natural air circulation
- Compliance: EN 50244, EN 60079-29-2
Safety Instructions:
- Professional recalibration at least once a year
- Keep clean – do not let the grid become dusty
- In case of gas alarm: Do not operate switches, do not use telephones, open windows
- Certified according to EN 50194-1 Type A, EN 60079-29-1, LVD 2006/95/EC, EMC 2004/108/EC
Monitoring devices
Other available sensors
Extension units
Accessories
DB9 LapLink Cable 2m A LapLink cable (also known as Lablink or null-printer cable) is a cable used to connect two computers directly via a cable connection. Housing: Plastic Type: Cable
Mounting Plate D Bracket for Ares and Poseidon2 Operating environment: -3°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 74 x 6 x 120 (W x H x D) / 58g Warranty: 24 months Wall mounting plate for Ares, Poseidon2 3266/68 and other products.
DIN-Rail Box Set A mounting kit for installing HW-group devices on a DIN rail. Applications and Use: Mounting kit for installing HW-group devices with metal housing on a DIN rail. Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 45 x 11 x 105 (W x H x D) / 22g
Mounting Kit Screw set for mechanical mounting Applications and Use: Screw set for mechanical fastening
Mounting Plate E- 1U Rack (cabinet) mounting plate, 1U mounting for HW-group Ares and Poseidon2 devices Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 127 x 45 x 94 (W x H x D) / 137g Warranty: 24 months Rack (cabinet) mounting plate, 1U mounting for HW-group Ares, Poseidon2 3266/3268 and other products.
Mounting Plate L DIN Rail DIN rail mounting plate for Ares, Poseidon2 3268, and other products. Features: Metal housing Wall mounting Applications and Use: Profiles for metal-encapsulated HWg devices for wall mounting. Dimensions: 150 x 120 x 45 (W x H x D) / 65g Warranty: 24 months
Mounting Kit for Poseidon2 4002 and HWg-SMS-GW3 Applications and Use: Mounting kit for Poseidon2 4002 and HWg-SMS-GW3 Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 136 x 45 x 16 (W x H x D) / 165g Warranty: 24 months
Rack Shelf 1U A versatile solution for easy mounting of HW-group devices in 1U racks. Operating environment: -30°C - 85°C / 0%RH - 100%RH Storage environment: -30°C - 60°C / 5%RH - 95%RH Dimensions: 485 x 44 x 104 (W x H x D) / 597g Warranty: 24 months Housing: Metal Type: Wall mounting This shelf makes it easy to use devices in racks. You can even combine different 1U products and sensors.
Software
Manufacturer information:
HW group s. r. o.
Rumunská 26
Prague, 120 00
Czech Republic
Phone: +420 222 511 918
Email: sales@hwg.cz
Responsible person:
Didactum® Security GmbH
Im Mühlenfeld 4
48163 Münster
Deutschland
Fon:
(+49) 250 19 71 63 54 / (+49) 171 33 11 577
Email: info@didactum-security.de
