A technician finds a halide leak detector torch in an older toolbox and wonders whether to use it while looking for a leak on an R-410A system. Why is that tool the wrong choice today?
Correct Answer
C) It reacts to chlorine, so it gives no response on a chlorine-free refrigerant, and its open flame breaks refrigerant down into toxic gas
The halide torch worked by drawing sample air across a heated copper element, where chlorine from an escaping refrigerant turned the flame green. Modern refrigerants such as R-410A contain no chlorine, so the flame never changes color no matter how large the leak is. On top of being blind to these refrigerants, the torch carries an open flame into an area where refrigerant vapor is present, and refrigerant passing over a flame or a hot surface breaks down into acidic and toxic products. Electronic, ultrasonic and bubble methods replaced it.
Why This Is the Correct Answer
The torch detects chlorine specifically. A chlorine-free refrigerant produces no reaction, which makes the instrument useless on most modern equipment, and the open flame turns any leaking refrigerant it does find into hazardous decomposition products right in the technician's breathing zone.
Why the Other Options Are Wrong
Option A: It is too sensitive for close work and alarms anywhere in the vicinity of the equipment, so the leaking joint can never be pinpointed with it
The halide torch was never known for excessive sensitivity. It was a coarse instrument that could miss small leaks even on the refrigerants it did respond to, so over-sensitivity is a complaint about modern electronic detectors instead.
Option B: It only works on a system that has first been pulled down into a vacuum, and this one is still holding its operating charge
Leak detection is done on a pressurized system, because nothing escapes from one under vacuum for any detector to sense. The torch's actual problem is what it reacts to, not the state of the system.
Option D: It can only be used on a system that has been pressurized with dry nitrogen, rather than one still holding its refrigerant charge
The torch responds to chlorine coming out of a refrigerant, not to nitrogen, so a nitrogen-pressurized system would give no color change at all. Nitrogen tests are read with bubbles or by watching the pressure.
Memory Technique
No chlorine, no green flame. The halide torch went out with R-12.
Reference Hint
Halide torches detect chlorine and are obsolete for chlorine-free refrigerants; refrigerant decomposes into toxic products at flame temperatures.
More epa-608-type-2 Questions
A walk-in cooler condensing unit holds a full charge of twenty-five pounds of R-404A, which is below the fifty pound threshold that brings an appliance under the leak repair provisions. What still applies to this unit?
An office building has thirty water source heat pumps on a common water loop, and each one left the factory assembled, hermetically sealed and charged with four pounds of R-410A. How is one of those units classified?
A data sheet for an unfamiliar refrigerant lists a boiling point of about fifty-five degrees Fahrenheit at atmospheric pressure. What does that tell a technician holding Core and Type II certification?
A technician holds Core, Type I and Type III certification and is sent to recover the charge from a twenty ton rooftop unit charged with R-410A. What does that combination of sections allow on this job?
A fleet garage technician holds only the vehicle air conditioning certification issued under Section 609 and is asked to recover the charge from the shop's own rooftop air conditioner. What does that credential allow?
A split system's outdoor unit, indoor coil and the line set the installer ran and brazed between them are being considered. For the purposes of the refrigerant rules, what makes up the appliance here?
On a new installation the line set is brazed to a factory charged outdoor unit and an indoor coil shipped under a nitrogen holding charge, with the outdoor unit's service valves still closed. What does the recovery requirement call for before that brazing?
A rooftop unit's data plate has weathered until the charge figure cannot be read, and the technician needs the full charge to place the appliance under the evacuation and leak provisions. Where should that figure come from?
A computer room air conditioning unit holds forty pounds of R-407C and connects to a remote air cooled condenser through refrigerant piping run and brazed by the installer. How is that unit classified?
A shop's office manager, who holds no technician certification, is sent to a supply house to pick up a new recovery machine for the commercial crew. What does the sales restriction require at that counter?
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