Using the Calibrator
To calibrate a Refrigerant Sniffer Leak Detector, the operator checks to assure that the pressure gauge needle of the FSLTC Calibrator is in the "OK" band. The operator then places the tip of the sniffer probe briefly into the tapered recess at the point source of refrigerant vapor flow of the FSLTC (in the end opposite the pressure gauge). The leak-rate reading of the Detector is then adjusted to the Certified Leak Rate of the Calibrator, as provided by VTI on the Calibration Tag and Calibration Certificate. A second reading is obtained in the same way to assure the calibration of the detector.
When the pressure decreases to the bottom of the OK band (due to the flow of refrigerant from the reservoir), the operator refills the reservoir to the top of the allowable band before using it to calibrate a detector. Depending on the leak rate, this is required every few weeks or months.
For background, each FSLTC Leak Standard is calibrated by VTI to the leak rate specified by the Customer, and the reservoir pressure that provides that leak rate is recorded. A green band marked "OK" is placed on the face of the pressure gauge identifying that pressure and the pressure range allowable to keep the leak rate within an acceptable +/- tolerance. Based on the accuracy and reproducibility of leak detectors, this is usually +/- 10% of the specified leak rate value. Thus, when calibrating a leak detector, the FSLTC reservoir pressure must be maintained within this "OK" band, to keep the leak rate within the allowable range.
