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Klein Tools® ET120 Combustible Gas Leak Detector

Model number
ET120

The Klein Tools ET120 Combustible Gas Leak Detector detects methane, propane, and other combustible gases with a detection range of 50 to 10,000 ppm via an 18-inch flexible gooseneck probe. Two sensitivity modes — High (50–1,000 ppm) and Low (1,000–10,000 ppm) — let users tailor sensitivity to conditions. Five red LEDs and an 85 dB audible alarm intensify as gas concentration rises. Auto power-off after 10 minutes conserves the 4 AAA batteries. Includes carrying pouch. Designed for plumbers, HVAC technicians, and utility workers. Backed by a 1-year limited warranty.

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Model no.
ET120
Brand
Klein Tools
Category
Gas Detector
Canonical URL
/klein-tools/gas-detector/et120-klein-tools-combustible-gas-leak-detector/
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§ Specifications

#specifications
Product Type
Combustible Gas Leak Detector
Gas Type
combustible (methane, propane, and other combustible gases)
Detection Range
50–10,000 ppm
Detection Sensitivity
High: ~50–1,000 ppm; Low: ~1,000–10,000 ppm
Alarm Type
Audible (85 dB) and visual (5 LED)
Battery Type
4 x AAA
Overall Length In
28.31
Assembled Weight Oz
13
Barcode (UPC)
092644690648
Warranty
1-year limited

§ What's Included

01 Gas Leak Detector
02 4 x AAA Batteries
03 Carrying Pouch
04 Instruction Manual

§ Warranty

1-year limited

§ FAQ

What gases does the ET120 detect?

Methane (natural gas), propane, and other combustible gases. Its catalytic bead sensor is calibrated for these common residential and commercial fuel gases. It does not detect carbon monoxide or refrigerants — use the ET110 or ET160 respectively for those gases.

What is the difference between high and low sensitivity modes?

High sensitivity responds at approximately 50–1,000 ppm, useful for locating the source of a small leak. Low sensitivity responds at 1,000–10,000 ppm, useful for confirming large concentrations without false positives from trace background combustible gases present in some environments.

How should I sample for leaks with the ET120's long probe?

Hold the probe tip within 1–2 cm of suspected leak points — pipe joints, valve stems, flex connectors, and appliance fittings. Move slowly to allow the sensor to equilibrate. The 28.3-inch probe length lets you reach fittings behind appliances without disturbing equipment.

What audible and visual alerts does the ET120 use?

An 85 dB audible alarm and a 5-LED visual indicator. Both alarm rate and LED count increase proportionally with gas concentration, helping you home in on the leak source by following the intensifying signal.

How does the ET120 differ from the compact ET190?

The ET120 has a 28.3-inch probe for reaching behind appliances and a higher concentration ceiling (10,000 ppm). The ET190 is pocket-sized (6.3 in, 1.8 oz) with a shorter range (2,000 ppm) and two AAA batteries. Use the ET120 for thorough gas appliance surveys; use the ET190 for everyday carry and quick checks.