another halocarbon, with the pressure increased with dry nitrogen to about 150 psig. Continue the leak check using an electronic leak detector. In most cases, you can find the leak by this method.In some severe cases, you may have to resort to removing the compressor and the oil separator from the system, increase the pressure in the other components to a higher pressure, install a pressure gauge, let the unit sit for 24 hrs, and watch for a drop in pressure. This method works well for locating a leak in areas that are hard to reach. Further teardown of the unit may be necessary if a leak is found. Contact the manufacturer for the correct pressures to use.The electronic leak detector is a fine and valuable instrument; however, it has its limits. Table 2 will help you with leak detection. Using R-12 as a reference of 1, you will have to have a leak rate approximately as much larger as shown in the third column, to be able to read it on the leak detector.