AC 7490
ELECTRONIC LEAK DETECTOR FOR NITRO-TRACE TESTING (N2-H2)
INSTRUCTIONS
Tracer gas consists of a non-toxic, non-fl ammable, environmentally friendly (non-polluting) mixture of 5% Hydrogen
and 95% Nitrogen. For this reason, the Tracer gas can be released into the environment after the leak
detection procedure is completed.
The Tracer gas mixture complies with Article 6, Paragraph 3 of EU directive 2006/40/EC.
The AC 7490 detects the Hydrogen component of the tracer and because Hydrogen molecules are so small, it is
an ideal gas for leak detection. The Tracer gas is charged into an empty system at a pressure of approximately 75
psi (5bar). As Hydrogen is lighter than air, always probe slightly above the suspected leak area. Once the source
of the leak is located and repaired, the Tracer gas can be released and the system
can be recharged again with refrigerant. A fi nal check should then be performed using a SAE certifi ed refrigerant
gas leak detector.
NOTE: Run engine with air conditioner on briefl y to properly distribute the H2 Tracer gas.
Batteries
lnstall Batteries: Remove screw located at rear end of unit and pull down
hinged battery door to open as shown. Always insert all four batteries into
the battery compartment in the same direction.
Note polarity mark on the inside of the battery door for proper battery
orientation.
Sensor
Replace Filter: Unscrew sensor tip as shown to replace fi lter. Replace fi lter whenever it becomes visibly dirty or
every 2 to 3 months depending on use.
Replace Sensor: Remove sensor by pulling out of socket. lnstall the new sensor by aligning the notch in sensor cover
with the raised keyway on sensor socket holder (see fi gure below).
Note : Do not force sensor into socket. Misalignment can damage the sensor pins.
