The new SAE International Refrigerant Leak Detector Standard J2791
Techno Tools Corporation, Models D440A, and D400
Because all vehicles are currently being designed with smaller a/c refrigerant charges and tighter seals, there is a need for an improved class of electronic refrigerant leak detectors capable of finding very small leaks. In response to this need, and to reduce refrigerant R134a emissions and establish leak detector performance standards, SAE International published a new automotive refrigerant leak detector Standard J2791 in September of 2008. Leak detectors that comply with J2791 will identify smaller refrigerant leaks when servicing all motor vehicle a/c systems and will deliver stable performance without false-triggering distractions. SAE J2791 has become the Standard by which all probe-type leak detectors should be measured.
The D440A and the D400 are compliant with J2791. The instruments were certified to comply by a qualified independent laboratory. The instruments have superior sensitivity to HFC refrigerants including R134a, as well as the newer refrigerant blends. They will also detect the proposed R134a substitutes such as R152a and HFO1234yf. Their solid electrolyte heated sensor technology is superior to the older corona discharge technology in detecting refrigerant gas leaks. Their design includes the use of four disposable AA batteries, to eliminate the drawback of using rechargeable batteries that can make an instrument useless when the battery pack becomes discharged and requires several hours to be recharged. Although the solid electrolyte sensor technology is heated, it is run cool enough to draw very little power and allows for about eight hours of continuous use. Additionally, the long life and stable sensor will not be poisoned by excessive exposure to refrigerant gas or become unstable over time and it is guaranteed to perform to its design specification for two years. No other supplier of leak detectors provides a warranty on their refrigerant sensor.
The D440A is designed with a unique numeric leak size indicator. This feature enables the user to quickly and accurately find the source of a leak as well as to provide the size of the leak. Just about any leak detector can detect a large cloud of refrigerant gas. Finding the source of the leak and to have an idea about the size of the leak is the ultimate goal. The D440A incorporates an accurate and useful numerical LED display that provides a number from 1 to 9 depending on the size of the leak. The LED display is independent of the audio alarm and the sensitivity settings. Without changing sensitivity settings and by simply watching the numbers on the display increase or decrease as the probe tip is moved closer or further from the leak source, the user can easily home-in on the leak source
The audio alarm of the D440A and the D400 incorporates three levels of sensitivity that changes the intensity of the alarm depending on the size of the leak detected further allowing the user to pin point the leak source. The flashing LED alarm light at the probe tip of the D440A is positioned directly where the technician is looking when leak checking. The LED gives the instruments one more added feature to be sure the user can find the leak source as quickly and as reliably as possible.
Paul Weissler, the Senior Technical Correspondent for the Mobile Air Conditioning Society Worldwide said in the September issue of MACS Service Reports in connection with the Standard…,”we strongly advise against “getting by” with the typical J1627 detector. Maybe that detector would have been adequate a few years ago, but it isn’t any more and surely will become less acceptable as new systems become a larger percentage of those in vehicles on the road.”
Excel Spreadsheet comparing the new SAE J2791 with the former SAEJ1627