Mastercool 55975 IntellaSense III is a pro-grade combustible gas leak detector built around a low-power metal oxide sensor for fast, sensitive sniffing on HVAC jobs. It’s quick to respond, easy to aim with a 15" probe, and rugged enough for service vans—bloody good for fault-finding in the field.

Key Features & Trade Benefits

• Heated tin-oxide (MOS) sensor — high sensitivity to tiny hydrocarbon leaks; isolates problems faster and cuts call-backs.
• <1 s response — track leaks in real-time around joints and valves; no waiting about.
• 50–1000 ppm sensitivity — suitable for most HVAC/heating gases from methane to propane and solvents listed below.
• 2000 h sensor life — fair dinkum longevity for busy service teams.
• 15" intelligent probe + environment sensor — reduces false alarms in tricky spaces; reach without contortions.
• Six-LED bar graph + Hi/Med/Low sensitivity & Peak — visualise leak size, lock peaks, and zero back quicker.
• Keypad with volume/mute — audible feedback your way; handy on noisy rooftops.
• Includes blow-moulded case, 2×C batteries, test vial, filters — ready for site straight out of the box.

Why This Detector Matters

On a steamy Brisbane arvo, chasing a “gas smell” around a rooftop meter set can be a time sink. With the 55975 on High, you’ll see the LED bar walking you straight to the culprit, then drop to Low to pinpoint the exact joint—too easy. If you’re comparing options, our Leak Detectors category gives a quick view of tracer-gas, refrigerant and combustible models.

Pro Tip

Give the sensor 30–60 seconds to stabilise in clean air, then approach suspected points slowly. Use Peak mode when multiple leaks are likely (e.g., manifold blocks) so you don’t miss the worst offender. Keep replacement filters clean to maintain response.

Compatibility & System Info

• Detects: Acetone, Acetylene, Ammonia, Benzene, Butane, Butanol, Chlorine, Ethane, Ethanol, Gasoline, Hexane, Hydrogen, Hydrogen Sulfide, Isobutane, Methane (natural gas), Methanol, Methyl Acetate, Methyl Chloride, Methyl Ether, Naphtha, n-Butane, Pentane, Propane, Propanol, Sulfur Dioxide, Trichloroethane.
• Use cases: HVAC piping and appliance checks, LPG installations, forming gas work, and general combustible leak location.
• Note: For A2L refrigerants (e.g., R32) follow Australian guidance to use detectors specific to combustible gases and the refrigerant class.

What’s Included

• Mastercool 55975 IntellaSense III detector
• Blow-moulded carry case
• 2 × “C” alkaline batteries (approx. 6000 mAh each)
• Leak test vial
• Replacement filters

Download the Instruction Manual (PDF).

Specifications

Specs per Mastercool/HVAC Shop product literature.

Warranty & Returns

Warranty: 2 years from purchase (consumables excluded). Backed by Australian Consumer Law and our store returns policy—no dramas.

FAQs

Q: Will it pick up LPG/propane and natural gas?
A: Yes—propane, butane, isobutane and methane are on the detection list.

Q: Does it have audible and visual alarms?
A: Yes—six-LED bar graph for relative leak size plus adjustable volume/mute via keypad.

Q: Any tips to avoid false alarms?
A: Let the probe’s environment sensor stabilise in clean air, then approach slowly; use lower sensitivity near known sources and re-check with Peak mode.

Q: Is it suitable for flammable refrigerants (e.g., R32)?
A: Use detectors designed for combustible gases and follow Australian guidance for A2L work; this model is a combustible gas detector—verify performance for your application and calibrate regularly.

Related Products

• Working with tracer gas? The Imperial LD-920 is a handy mate for pinpointing tiny leaks using H₂/N₂.
• Prefer an intrinsically safe option? INFICON GAS-Mate is worth a look for appliance and LPG work.
• Not sure which way to go? Browse all leak detectors to compare sensitivity and sensor types in one place.