Which method is appropriate for properly calibrating an electronic leak detector?

Using a reference gas is the appropriate method for properly calibrating an electronic leak detector. Calibration ensures that the detector provides accurate readings when identifying leaks. A reference gas, typically a known concentration of a refrigerant, is used to create a controlled environment where the detector can be tested and adjusted for precision. This method allows technicians to set the sensitivity levels of the detector according to industry standards, ensuring that it can effectively detect real leaks in the field.

The other methods, while they may have their uses, do not provide a reliable means of calibration for leak detectors. Leaving a detector idle for 24 hours does not account for shifts in sensitivity or precision within the device that might occur over time. Testing with multiple refrigerants may not yield accurate results either, as different refrigerants can behave differently in terms of detection sensitivity. Cooling the detector in a freezer is not a standard practice for calibration and may not provide insights into the accuracy of the device in typical operating conditions. Thus, using a reference gas remains the best practice for ensuring that electronic leak detectors are functioning correctly and reliably.