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9. TEST SET OPERATION
A. Preliminary Setup
1. Ensure that the 1811NG Power ON//OFF switch (8) is in the OFF position prior to
connecting the AC power cable.
2. As a standard practice and under normal circumstances it is recommended that the
1811NG not have hoses connected prior to initialization. This is not a requirement just
an additional precaution.
Figure 46
1811NG Front Panel
B. Power ON
During normal use, it is recommended that the Test Set is powered ON and allowed to
complete its Power ON initialization process prior to connecting the hoses to the STATIC
(Ps) and PITOT (Pt) ports. During power ON initialization the following discovery occurs:
1. The Test displays a power ON initialization window during this phase as shown above.
There is a log file created that records all the initialization steps and results that occur
during this phase.
2. The Test Set measures the initial pressure found on STATIC (Ps) and PITOT (Pt) ports
and records it as a temporary value.
3. The ambient pressure is measured and recorded as a temporary value. This value will
be used by the Go To Ground function.
4. The Pt measurement channel performs a Qc auto-zero to trim any small offset that has
occurred.
5. An internal control channel leak test is performed. The control channel leak test should
not be confused with the actual leak test of the Test Set itself. The control channels are