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Mastering Your Meter Advanced Functionality with Louise Kellar (UEi Test Instruments)

By Bryan Orr Louise Kellar

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In this episode, Bryan welcomes back Louise Kellar of UEi Test Instruments for a deep dive into getting more out of a digital clamp meter than the basic volts, amps, and ohms most techs rely on every day. The tool in the spotlight is UEi’s High Accuracy Clamp Meter (HAC), which is accurate when dealing with the low current draws common on modern condenser fan and blower motors and is critical for reliable wattage and capacitor-under-load testing.

The podcast also walks through a series of lesser-used but valuable meter functions, including microamp measurement for flame rectification testing, diode testing for diagnosing boards on mini-splits, the Low Z setting for eliminating ghost voltage readings and safely bleeding capacitors, and the safety-locking temperature toggle that prevents technicians from accidentally crossing voltage and thermocouple leads.

Bryan and Louise also cover common mistakes, such as not knowing when to use continuity or resistance and auto-ranging mistakes, as well as some crucial takeaways about true RMS measurements, temperature settings, and CAT safety ratings.

This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, NAVAC, and Filtrete.

Resources

Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

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#carbon monoxide #CO #continuity #electrical meter #hvac #microamp #multimeter #resistance #true rms #uei

Author:

Bryan Orr

Company: Kalos Services

Position: Co-Founder and President

Louise Kellar

Company: UEi Test Instruments

Position: National Training Manager

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In this episode of the HVAC School Podcast, Bryan welcomes back Bill Spohn to talk about carbon monoxide and a troubling trend in the alarms being sold online. They start with the basics: the difference between a standard UL 2034 alarm and a true low-level CO monitor. UL 2034 alarms were designed to avoid nuisance calls, so they can stay silent through long exposures at relatively low concentrations. Low-level monitors are far more sensitive and can warn you that something is brewing before it becomes a life-threatening emergency.

Bill explains why that gap matters, walking through how carbon monoxide displaces oxygen on hemoglobin, why it lingers in the body, and why children, older adults, and people with heart or lung conditions are especially vulnerable. Bryan adds the troubleshooting angle: a UL 2034 alarm is the safety net that keeps people from dying, but low-level monitoring helps you find and fix a problem early, much like catching a refrigerant leak before the system is flat.

The conversation then turns to the main story. Bill bought a pair of inexpensive alarms advertised as both low-level and UL 2034 compliant, which is a contradiction, since the two cannot be the same device. They arrived with no instructions, no model number, and no visible certification control number, and they closely resembled a product tied to a Consumer Product Safety Commission warning covering roughly 375,000 units and 91 reported failures to alarm. Bill traces the marketing back to what appears to be a single factory selling under many brand names, backed by a virtual office address, a fake firefighter endorsement, and a flood of promotional emails.

Bryan and Bill close with lessons for technicians, consumers, and manufacturers alike. Be skeptical when price and performance seem too good to be true, verify who is behind a brand, and remember that claiming to meet a standard is not the same as being independently certified. They also urge established manufacturers to be humble, test claims thoroughly, and make sure published specifications reflect how their sensors actually perform.

Topics Covered

Low-level CO monitors versus UL 2034 alarms, and why they are not interchangeable
How the 1990s Chicago nuisance-alarm events led to the UL 2034 standard
Why standards built around healthy adult males leave gaps for vulnerable people
How carbon monoxide binds to hemoglobin and why it accumulates in the body
Why “CO leak” is the wrong phrase: carbon monoxide is created, not transported
Online alarms claiming to be both low-level and UL 2034 compliant
The Consumer Product Safety Commission alert and the 91 reported failures to alarm
Red flags: no instructions, no model number, no certification mark, a virtual-office address, and a fake endorser
What the alarm test button actually checks (the circuit and horn, not CO response)
The challenge of validating alarms without accessible CO test kits
How to vet unfamiliar brands, including using AI to research price, company history, and website age
Sensor signal smoothing and why muted low-end readings can mislead users
A call for manufacturers to test in the field and for honest specification claims
Why price alone should never drive the purchase of life-safety devices

This episode contains embedded sponsor messages from Refrigeration Technologies, Carrier, White-Rodgers by Copeland, Santa Fe Dehumidifiers, and TruTech Tools.

Resources

Purchase your tickets or learn more about the 8th Annual HVACR Training Symposium at https://hvacrschool.com/symposium.

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