EN 14624-2020 pdf download.Performance of portable locating leak detectors and of fixed gas detectors for all refrigerants.
portable leak detector under test are positioned according to apparatus no 1. While the probe tip is held in the position away from the calibration leak, the portable leak detector is turned on and allowed to warm up per the manufacturer’s instructions.
Using apparatus no. 1, the probe tip is moved to the position directly in front of the calibration leak where it is held for a time not longer than 10 s. The probe is then moved away from the calibration leak and the portable leak detector is allowed to recover. This procedure is repeated 10 times and the indication given by the portable leak detector while the probe is in front of the calibration leak is recorded each time. An indicating type leak detector Is deemed to have successfully detected the leak If it gives an audible or visual alarm all 10 times. A measuring type leak detector is deemed to have successfully detected the leak if it gives a reading within ± 20 % of the nominal value of the calibration leak used.
If the portable leak detector successfully detects the leak, the calibration leak is changed to a smaller value. If the portable leak detector does not successfully detect the leak, the calibration leak is changed to a larger value. This test procedure is repeated with successively larger or smaller calibration leak sizes until the detection limit of the portable leak detector is determined. Suggested leak rate values are lOg/a.5g/aand3g/a.
8.3 Test no. 2: Dynamic detection limits
The portable leak detector is placed on apparatus no. 2. A calibration leak with nominal leak rate equal to 5 g/a of the representative gas specified in Table 3 is positioned so its orifice or membrane is at a distance of 3 mm ± 0,5 mm from the probe tip (see Figure 1 — Measuring distance) at its closest approach during travel. The travel speed of the apparatus is adjusted so the probe tip moves at a speed of 2,0 cm/s ± 0.2 cm/s In front of the calibration leak The ends of travel are adjusted to be 10 cm ± 1 cm to either side of the calibrated leak orifice or membrane. The probe is allowed to stop at the end of travel for no longer than 2 s before beginning the next sweep past the calibrated leak
The enclosed testing chamber type enclosure is closed, the moving platform or arm is moved to one end of its travel, and the portable leak detector is turned Ofl and allowed to warm up per the manufacturer’s instructions. The moving platform or arm is operated so the portable leak detector probe passes in front of the calibration leak a total of 10 times and the indication given by the portable leak detector as the probe passes in front of the calibration leak is recorded each time. An indicating type leak detector is deemed to have successfully detected the leak if it gives an audible or visual alarm all 10 times. A measuring type leak detector is deemed to have successfully detected the leak if it gives a reading within ± 20 % of the nominal value of the calibration leak used for all 10 times.
If the portable leak detector successfully detects the leak, the calibration leak is changed to a smaller value. If the portable leak detector does not successfully detect the leak, the calibration leak is changed to a larger value. This test procedure is repeated with successively larger or smaller calibration leak sizes until the detection limit of the portable leak detector is determined. Suggested leak rate values are lOg/a,5g/aand3g/a.
8.4 Test no. 3 Dynamic detection limit in a contaminated environment
The portable leak detector probe is placed on apparatus no. 2 (placed inside apparatus no. 3a). A calibration leak with nominal leak rate equal to the detection limit determined in Test no. 2 is positioned so its orifice or membrane is at a distance of 3 mm ± 0,5 mm from the probe tip (see Figure 1 — Measuring distance) at Its closest approach during travel. The travel speed of the apparatus is adjusted so the probe tip moves at a speed of 2.0 cm/s ± 0,2 cm/s in front of the calibration leak The ends of travel are adjusted to be 10 cm ± 1 cm to either side of the calibrated leak orifice or membrane. The probe is allowed to stop at the end of travel for no longer than 2 s before beginning the next sweep past the calibrated leak.
The enclosed testing chamber type enclosure is closed. The concentration of refrigerant gas inside the enclosure is adjusted to the maximum detectible concentration of the portable leak detector specified by the manufacturer or 1 000 ppm ± 10% of the representative gas specified in 7.1 whichever is lower. The concentration is generated by a gas mixing device or e.g. by injection of a defined volume of refrigerant gas with a syringe into the enclosed testing chamber type enclosure of known volume containing air.
The moving platform or arm is moved to one end of its travel, and the portable leak detector is turned on and allowed to warm up per the manufacturer’s instructions and if there is a zeroing procedure of the portable leak detector recommended by the manufacturer, it is applied. The moving platform or arm is operated so the portable leak detector probe passes in front of the calibration leak a total of 10 times and the indication given by the portable leak detector as the probe passes in front of the calibration leak is recorded each time. An indicating type leak detector is deemed to have successfully detected the leak if it gives an audible or visual alarm all 10 times. A measuring type leak detector is deemed to have successfully detected the leak if it gives a reading within ± 20% of the nominal value of the calibration leak used for all 10 times.
If the portable leak detector successfully detects the leak, the calibration leak is changed to a smaller value. If the portable leak detector does not successfully detect the leak, the calibration leak is changed to a larger value. This procedure Is repeated with successively larger or smaller calibration leak sizes until the detection limit of the portable leak detector is determined.
8.5 Test no.4: Response time
A calibration leak is used that has a nominal leak rate equal to at least the static lower detection limit determined by test no. 1 but not more than 4 times that static lower detection limit. The portable leak detector is turned on and allowed to warm up per manufacturer’s instructions.
Using apparatus no. 1, the probe tip is moved to the specified position directly in front of the calibration leak at a distance of 3 mm ± 0.5 mm for a time not longer than 10 s. The probe is moved away from the calibration leak and allowed to recover. EN 14624-2020 pdf download.