Figure 13-17. - Typical electronic leak detector.

This type of leak detector is the one most widely used today (fig. 13-17).

PROPANE TORCH DETECTOR

The propane torch detector shown in figure 13-18 is still used in the air conditioning field; however, it is rapidly being replaced by electronic devices.

CAUTION The propane torch detector works by burning small amounts of R-12. In doing so, phosgene gas is produced. Phosgene gas can result in fatal injury; therefore, use this device in well-ventilated areas only.

The propane flame draws the leaking refrigerant over a hot copper alloy reactor plate, and a marked color change of the flame occurs if refrigerant is present.

CAUTION The vehicle's engine must not be running when making this test.

To conduct this test, you should take the following actions:

1. Open the propane valve and light the torch.

2. Adjust the flame just high enough to heat the reaction to a cherry-red color.

Figure 13-18. - Flame type of leak detector.