56-101-01175 Revision H Page | 38Figure 30 Select ATP Leak Test ProfileThe ATP Leak Test provides the following profile options:a) ALR “Auto Leak Recover” can be “(X)” selected/deselectedb) Ambient Comp can be “(X)” select/deselectedAmbient Comp compensates for local ambient barometric pressure to ensure forexample that a 5,000 ft. leak test is really checked at a pressure altitudeequivalent to 5,000 ft. above the local barometric pressure.c) Pass Limits can be “(X)” selected /deselected which determines whether or notpass/fail limits are used. If Pass Limits is selected “(X)”, the user can specify thepass limit value for each of the 3 possible leak tests.Note: Regarding the actual Leak Test(s), there are 3 possible leak tests that canbe selected. (1) Pt channel, (2) Ps Low ALT and (3) Ps High ALT.Note: For the Pt channel leak, the ATP will automatically take the Ps channel toground prior to starting the Pt channel leak test.d) Wait: The wait time is the time allowed for the system under test to settle andstabilize after the target CAS or ALT has been reached. The general rule is thehigher the target CAS or ALT the longer the wait time. That time should be usedto allow for adiabatic to settle so that the leak measurement truly represents thesystems leak rate and is not influenced by the expansion/contraction of gases ina closed system. The Pt and Ps Low ALT share the same Wait time value whilethe Ps High ALT has its own wait time value specified.e) Measure: The measure time is simply the amount of time to allow for the leakmeasurement cycle. Typically 1:00 minute is used for Pt & Ps Low ALT and alonger time may be used for Ps High ALT.f) Run: begins executing the ATP leak test that is presently loaded as defined.g) Save: simply saves the present ATP leak test parameters as presently defined.h) Cancel: exits the ATP leak test. Any changes made to the ATP leak testparameters will not be saved.
