Best Ultrasonic Leak Detectors for HVAC Technicians: 7 Picks
A comparison of seven ultrasonic leak detectors for HVAC technicians, covering frequency range, audio and visual output, and the jobs each one suits.
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Gas leak detectors, CO, methane, refrigerants and multi-gas meters.
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Best Hydrocarbon Refrigerant Leak Detectors: 7 Picks for R290 and R600a
A comparison of seven refrigerant leak detectors whose listings state R290 or R600a coverage, with the sensor types, stated sensitivities and the halogen-only traps to avoid.
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Best Carbon Monoxide Meters for Furnace Servicing: 6 Picks
Six CO meters for furnace servicing, compared on range, resolution, alarm thresholds, calibration data and logging, with the limits of each stated plainly.
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Seven Gas Detector Calibration Kits for Field Technicians
Seven calibration kits and components compared on blend, cylinder size, regulator type, and what the listing does and does not publish.
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Best Propane Leak Detectors for Grills: 6 Picks for Cylinders, Hoses and Regulators
Five electronic sniffers and one brass tank gauge, sorted by probe reach and stated detection range, for the four places a grill actually leaks.
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Best R410A Refrigerant Leak Detectors: 6 Picks for Air Conditioning Service
Six leak detectors that cover R410A, sorted by sensor technology, published sensitivity and what each one costs to keep running.
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Best Plug-In Carbon Monoxide Detectors: 6 Alarms With Battery Backup
Six plug-in carbon monoxide alarms, all with battery backup, sorted by backup cell type, whether they show a digital level, and how they behave at night.
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Best H2S Gas Detectors: 6 Picks for the Gas That Disables Your Sense of Smell
Six hydrogen sulfide instruments, from maintenance-free single gas clips to four gas monitors with pumps, sorted by how each one is meant to be worn and maintained.
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Elitech ILD-100H vs Fieldpiece DR58: Two Heated Diode Leak Detectors
Both use heated diode sensors. The Elitech states maximum sensitivity of 0.1 oz per year with three sensitivity levels and a TFT screen; the Fieldpiece states below 0.03 oz per year, IP54 and a 300 hour sensor life.
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TopTes Guard-101 vs Forensics Detectors 4 Gas Meter: Which Four Gas Monitor?
Both monitor oxygen, carbon monoxide, hydrogen sulfide and combustibles. The Guard-101 states a 14 hour battery and alarm record storage; the Forensics unit states NIST calibration and zero and span calibration options.
Read Guide→Klein ET120 vs TopTes Guard-101: A Leak Finder and a Personal Monitor Are Not the Same Tool
The ET120 finds combustible gas leaks from 50 to 10,000 ppm. The Guard-101 is a wearable four gas monitor for H2S, CO, LEL and oxygen with a stated 14 hour battery.
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UEi CD100A vs TopTes PT199: Long Gooseneck or Pocket Sniffer?
The CD100A states an 18 inch gooseneck with a tip light and seven detectable gases. The PT199 is a compact unit stating a 0.5 second alarm, a red high-level screen and included batteries.
Read Guide→Product Reviews
Elitech ILD-200 Review: An Infrared Sensor and the One Number Rivals Will Not Print
An infrared refrigerant leak detector with a published minimum detectable leak rate of 1 g/a, four sensitivity steps each with its own rate, and a ten year sensor life.
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Forensics Gas Leak Detector Review: Five Bullets, and Two of Them Are the Right Two
A combustible gas detector with a Japanese sensor calibrated to methane, a stated seven year sensor life and a ten foot drop rated housing.
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SENSYX Refrigerant Leak Detector Review: A Listing That Teaches You to Use It Properly
A rechargeable halogen leak detector with a metal oxide sensor, selectable sensitivity, a live ppm reading and a published warm up and sweep technique.
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TEKCOPLUS H2S Detector Review: A Single Gas Monitor for Hydrogen Sulfide
A portable electrochemical hydrogen sulfide monitor stating adjustable high and low alarms, a selectable buzzer, a backlit LCD with data hold and a clip for wearing.
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TopTes AT-505 Review: A 0 to 100 PPM Ammonia Monitor for Livestock Buildings
A rechargeable ammonia detector stating a 0 to 100 ppm range, a 4000 mAh battery giving over 60 hours, a TFT colour screen with dual display modes, maximum value hold and adjustable thresholds.
Read Review→TopTes PT520A+ Review: A 17 Inch Gooseneck and a Published PPM Range
A rechargeable combustible gas detector stating a 50 to 10,000 ppm detection range, a 17 inch bendable gooseneck, 0.5 second response, seven coloured bars with a 75 dB buzzer and over 3,000 recharge cycles.
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TopTes PT177 Review: A Pocket Gas Sniffer With a Warm-Up Warning on the Box
A pocket combustible gas detector stating LPG, methane, ethane, propane, butane, natural gas and coal gas, a 30 second warm-up in clean air, alarm within 0.5 to 3 seconds and five LEDs with a 75 dB alarm.
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TopTes CT-580 Review: A 0 to 1000 PPM CO Meter With Calibration Options
A rechargeable portable carbon monoxide meter stating a DDS sensor with response within 0.3 seconds, a 0 to 1000 ppm range, two alarm thresholds, a TFT colour display and zero and standard gas calibration.
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Kidde Portable Carbon Monoxide Detector Review: An Alarm That Travels
A battery powered carbon monoxide alarm using an electrochemical sensor, stating an 85 decibel alarm, LED status indicators, two AA cells included and wall or tabletop use.
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Forensics Detectors 4 Gas Meter Review: NIST Calibration and User Span Adjustment
A four gas confined space monitor for oxygen, carbon monoxide, hydrogen sulfide and combustibles, stating USA NIST calibration, factory calibration, zero and span calibration options and adjustable alarms.
Read Review→Elitech ILD-100H Review: A Heated Diode Sniffer With a TFT Screen
A heated diode refrigerant leak detector stating three sensitivity levels, maximum sensitivity up to 0.1 oz per year, and a TFT screen showing sensitivity, alerts and battery level.
Read Review→TopTes Guard-101 Review: A Wearable Four Gas Monitor With a 14 Hour Battery
A personal four gas monitor for hydrogen sulfide, carbon monoxide, combustibles and oxygen, stating a 14 hour battery, LED, vibration and sound alarms responding within 0.5 seconds, and alarm record storage.
Read Review→Learning Center
Flexible Gooseneck vs Fixed-Probe Gas Detectors: Which Design Finds Leaks Faster?
A gooseneck finds leaks faster on fittings you cannot reach: behind ranges, above water heaters, inside RV cabinets. A fixed probe deploys faster in the open.
Read Article→Gas Sniffer Warm-Up Time Explained: Why Testing Too Early Gives Bad Results
Warm-up brings a sniffer sensor to working temperature and sets its clean-air baseline. Skip it, or run it next to the leak, and the tool under-reads.
Read Article→Why Refrigerant Leak Detectors Miss Tiny Leaks and How Technicians Find Them
Detectors miss tiny leaks when the sweep is fast, sensitivity is wrong, air is moving, the sensor is tired or the zero is off. Slow and close finds them.
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Tracer Gas Leak Detection: Why Hydrogen-Nitrogen Testing Is Growing in HVAC Work
Tracer gas testing fills an empty system with 5 percent hydrogen in 95 percent nitrogen and sweeps with a hydrogen detector. No refrigerant is vented.
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R-32 and R-454B Leak Detection: Why Older Refrigerant Detectors May Not Be Enough
R-32 and R-454B are mildly flammable A2L refrigerants. An older detector may sense them, but unless its maker states A2L suitability it was not built for them.
Read Article→A2L Refrigerant Leak Detectors Explained: What HVAC Technicians Need to Change
An A2L refrigerant leak detector responds to R-32 and R-454B and is rated for use around a mildly flammable gas. Check the listing for the A2L label first.
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What Does PPM Mean on a Gas Detector? Reading Parts per Million Without Guesswork
PPM is parts per million: gas molecules per million molecules of air. 10,000 ppm is 1 percent by volume, and 50,000 ppm of methane is its explosive limit.
Read Article→Single-Gas vs Multi-Gas Detector: Which Monitor Does Your Job Actually Need?
A single-gas monitor watches one known hazard; a four-gas monitor watches O2, LEL, CO and H2S in unassessed spaces. Confined-space entry needs four-gas.
Read Article→Refrigerant Leak Detector vs Combustible Gas Detector: Two Sniffers, Two Chemistries
Refrigerant detectors sense halogenated refrigerants; combustible gas detectors sense methane and propane. Only a dual-chemistry unit like the DRX3 does both.
Read Article→Fieldpiece DRX3 vs DR58: New All-in-One Technology vs Proven Heated-Diode Detection
Both are heated-diode units. The DR58 states 0.03 oz/yr, a 300 hour sensor and 18 hour battery; the DRX3 adds A3, combustible gas and a replaceable sensor.
Read Article→Fieldpiece DRX3 vs DR82: Which Leak Detector Makes More Sense for Modern Refrigerants?
The DRX3 covers A3, A2L and A1 refrigerants plus combustible gases on a replaceable heated-diode sensor. The DR82 is infrared with a stated 10-year sensor.
Read Article→TopTes PT520A vs PT199: Gooseneck or Pocket Sniffer for Your Home?
The PT520A adds a 17-inch gooseneck, a 50 to 10,000 ppm range, a mute and a case. The PT199 is pocket-sized, tops out at 1,000 ppm and costs less shelf space.
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