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Calibration Description
The date of calibration adjustment is logged and stored during this procedure. It is important that the
ADTS Touch clock date is checked before starting a calibration adjustment or an incorrect date may
be recorded. Instructions for checking and setting the time and date can be found in section Settings.
"As found" data does not have to be recorded before an adjustment to the selected channel has been
carried out. Record "as found" date as required.
Preliminary operations
1)
Review and become familiar with the whole procedure before beginning the calibration process.
2)
Allow at least two hours for the ADTS to thermally stabilize after switching on and before
performing any calibration routines.
3)
Before starting a calibration procedure carry out a leak test, see section ADTS Leak Check.
4)
The pressure reference level of the ADTS is the top face of the front panel when the front panel
is facing upwards, see also, section Positioning the ADTS. In calibration check mode the ADTS
sets its altitude correction to zero.
Calibration check
This procedure checks the calibration accuracy without adjusting it. It may be used either to see if the
system requires a calibration or to verify performance following a calibration adjustment.
1)
Ensure the standard and the ADTS are at atmospheric pressure.
2)
Connect your calibration standard to the Ps or Pt channel.
3)
Open the "Tools" menu, select "Calibration (Calibrate sensors), enter your PIN, select "Sensor",
"Calibration check" sub-menu showing the current values for Ps and Pt.
4)
Apply pressure to the selected channel to Full Scale (FS) and lowest point, repeat this process a
minimum of three times.
5)
Adjust the calibration standard to apply pressure to the Ps or Pt channel. To decide if the applied
pressure is stable ensure that the value of the ADTS displayed pressure equivalent to a resolu-
tion of 0.001 mbar is stable, within ±0.001 mbar, and free from "creep". Calculate the actual
applied pressure reading to at least 4 decimal places. No data is entered to the ADTS when
performing a calibration check. Reference pressure entries are for the sensor adjustment oper-
ation only.
6)
The leak rate must be low enough to prevent the primary standard dead weight tester piston
from moving outside the mid operating point during the calibration procedure.
7)
Compare the applied pressure value on the calibration standard to the value displayed on the
ADTS and record the difference.
8)
If the recorded difference exceeds the allowable tolerance, carry out the "Calibration adjust-
ment" procedure detailed .
9)
Repeat this procedure for the other channel.
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