6600-NG User’s Manual
125-9110A
Page 75
SECTION 6 : CALIBRATION
6.1
EQUIPMENT
This calibration procedure requires the following equipment:
1.
Vacuum pump for Pressure Standard
2.
Pressure supply of clean, Dry air (dew-point below -10
o
C) at 25 psig, for Pressure Standard
3.
Pressure standard with two independently controlled outputs as follows:
a.
Output-1 should be able to generate differential pressures (with respect to Output-2)
between 0 and 30 inHg, with an accuracy of at least 0.002 inHg.
b.
Output-2 should be able to generate absolute pressures between 1.6 and 38 inHg, with
an accuracy of at least 0.002 inHg.
6.2
6600-NG TRANSDUCERS
Pt Transducer
The Pt output of the 6600-NG has a differential transducer with a range of 0 to 30 inHg differential. The
differential pressure is measured with the pressure at the Ps1 output as the reference. This transducer must
be calibrated at 0 inHg differential and 30 inHg differential (with respect to Ps1). The accuracy of this
transducer is ± 0.003 inHg.
Caution:
The pressure applied to the Pt output of the 6600-NG must never be less than the pressure on
the Ps1 output. If the Pt pressure is such that the Qc inHg (differential with respect to Ps1) is more
negative than -0.05 QcinHg, the Pt pressure will not be correctly displayed.
Ps1 and Ps2 Transducers
The Ps1 and Ps2 outputs of the 6600-NG have absolute transducers with a range of 1 to 38 inHg absolute.
These transducers must be calibrated at 1.6 inHg and 38 inHg. The accuracy of these transducers is ± 0.002
inHg.
6.3
SETUP OF 6600-NG
To perform a calibration press
FUNC
and then select ‘
8
’. However, before selecting the calibration
function it is necessary to set Pt units to ‘QcinHg’, Ps2 units to ‘inHg’ and the Ps1 units to ‘inHg’. Also,
all 3 outputs must be in Measure mode. If this is not set up correctly and Function ‘
8
’ is selected, the
following screen will appear.
