User Manual

Unit Description

Air-Radicator Purging

When a refrigerant source has been determined to be pure (at least 98% by weight of

either R-12 or R-134a), the instrument automatically offers the air purging feature to the

user, should there be any air contamination. Continuous monitoring of the venting gas

stream to determine exact air concentrations controls the purging feature. Purging limits

can be set by the user between 2%–9% by weight to tailor the purge to specific needs.

The instrument controls all functions of the purging feature with no intervention by the

user required to complete the procedure. The user can halt or cancel this procedure at any

time.

Control of the purge operation is achieved through direct measurements of refrigerant

concentration and is not dependent upon temperature or pressure measurements. Existing

technology in the vehicle air conditioning market typically uses both pressure and tem-

perature measurements to determine air concentration and to control the purging proce-

dure. Pressure-temperature technology is susceptible to errors induced by refrigerant

contamination and difficulties in obtaining precise temperature and pressure measure-

ments. This is due to the inability to account for rapid temperature and pressure drops of

the refrigerant during the purge procedure by temperature-pressure based equipment or

procedures. Temperature-pressure based technology commonly requires the refrigerant

source to come to a temperature-pressure equilibrium before purging can begin. This

process can take as long as eight to 24 hours.

With direct measurement of refrigerant concentrations, there is no need to wait for a

refrigerant source to reach a temperature and pressure equilibrium. Also, rapid tempera-

ture and pressure changes during purging operations do not affect the measurements.