Getting the Most from Final Inspection of Packaged RAC Products

Some manufacturers of refrigerators or air conditioners use the "box test" just before shipping the product. During a box test, the sniffer probe is inserted into the packaging of the fully packaged product. This test assures that the product arrives at the customer's facility with refrigerant intact. If the product fails this final box test, then it is clear that there is refrigerant leaking at a high rate and the problem can be remedied before the product ships to the customer.

The real leak rate for the "box test" is much higher than what the leak detector displays. Here is why:

If the sniffer measures the leak directly:

All the refrigerant molecules are in the sniffer line → real leak rate displayed

If the sniffer measures the same leak inside a big volume:

Only a few refrigerant molecules are in the sniffer line → much lower leak rate displayed

Depending on the volume of the box and the time between packaging and the box test, the real leak rate is 50 to 200 times higher than what the leak detector displays.

Guidelines for the Best Results from a Box Test:

• This test should be performed far away from the refrigerant filling station.
• Use the longest possible time between packaging and the box test.
• Use the lowest possible trigger level without getting false alarms due to background variations of the refrigerant.
• Position the sniffer tip next to the most probable leak location, not on the other side of the packaging.
• The measurement inside the packaging should take at least 3 seconds with the HLD5000 and at least 2 seconds with the Ecotec E3000.
• When using the INFICON HLD5000, use the sniffer tip extension (511-020) to enter the packaging. The standard sniffer tip has a front inlet and a side inlet. The side inlet must not enter the packaging, or the leak will not be displayed.

For more information on introducing Box Tests to your production line, contact your local INFICON support center. You can also email us at reachus@inficon.com, or click here to request someone contact you.