User Manual

Operating Procedures

Time Out: To conserve refrigerant during a potentially long purging procedure, the

instrument automatically halts the operation after a time-out of 1-1/2 hours. You are

asked if the procedure is to continue. To restart the procedure, press the “A” button;

press the “B” button to end the session and return to calibration. Note that purge

duration in excess of 1-1/2 hours is unusual (assuming a 50 lb. cylinder or smaller is

being purged) and can be caused by high levels of air contamination, refrigerant

contamination other than R-12, R-134a, R-22, or hydrocarbons, or by absence of liquid

refrigerant in the refrigerant source.

Calibration: To keep the instrument at peak accuracy, an occasional self-calibration is

performed. The purge procedure is momentarily halted until completion of the 20-

second self-calibration operation. The self-calibration automatically occurs after the

first five minutes of the purging procedure, and then at 10-minute intervals thereafter.

The calibration operation is fully automatic and requires no intervention.

Normal Purging Procedure: During the purging process, the instrument displays

NOW AIR IS XX.X% PURGING TO X.X%. Purge times vary with application and

are dependent upon headspace size in the source, amount of initial air contamination,

and the purge limit setting, Typically, it requires three minutes to purge an automotive

air conditioning system from 8% to 2% contamination levels. A typical 50 lb. storage

cylinder that is at least 50% liquid requires one hour to reduce the contamination levels

from 8% to 2 %. Observation of the instrument display reveals the air contamination

levels may rise and fall during the purging procedure. This fluctuation is normal and is

the result of air coming out of liquid solution and repeated refrigerant displacements of

the air.

5. When the purging procedure is complete, the instrument display reads DONE, AIR IS

X.X% PRESS B TO EXIT and the green LED flashes. Press the “B” button to exit the

purge operation and return to the calibration operation to be ready for another

refrigerant identification procedure. Replace the cap on the purge port, and disconnect

the service end of the sample hose BEFORE calibration occurs. If the instrument will

not be used again at this time, unplug the power cord to power down the instrument.