Use the graph or tables below to determine the range of air leakage you can test with the Lynx using our standard orifice plates.

Note that the data is based on laboratory tests with short lengths of hard pipe attached to the duct leakage tester. Actual field performance will likely result in reduced performance due to: (1) amount of flexible duct used; (2) number of bends in flexible duct; (3) size of duct system; (4) line voltage. To account for flexible duct and 90 degree bends, use our program that takes these in-line losses into account.

1-inch Orifice Plate

System Static Pressure (in.wg.)Min Leakage (cfm)Max Leakage with Lynx Tester (cfm)
1932
2930
3927
4923
5917
6910
796
8

2-inch Orifice Plate

System Static Pressure (in.wg.)Min Leakage (cfm)Max Leakage with Lynx Tester (cfm)
134150
234135
334120
434105
53485
63450
73425
8

3-inch Orifice Plate

System Static Pressure (in.wg.)Min Leakage (cfm)Max Leakage with Lynx Tester (cfm)
182355
282325
382320
482285
582230
682140
78255
8

4-inch Orifice Plate

System Static Pressure (in.wg.)Min Leakage (cfm)Max Leakage with Lynx Tester (cfm)
1175550
2175540
3175510
4175455
5175365
6175290
7175175
8

Min Leakage is the recommended minimum flow rate based on a 0.4 in.wg. pressure drop across the orifice plate. For example, approximately 82 cfm through the 3-inch orifice plate results in a 0.4 in.wg. so 82 cfm is the recommended minimum leakage. Though it possible to use the orifice plates at pressure drops lower than 0.4 in.w.g, note that accuracy of the reading is decreased.