HVG-2020B Instruction Manual
EAR99 Technology Subject to Restrictions Contained on the Cover Page
Page 26 of 40
Calibration Using Actual Gas
The HVG-2020B can be calibrated using a specific gas to provide better accuracy.
1.
Make sure the HVG-2020B has already been calibrated in nitrogen, but this adjustment will not affect
the nitrogen calibration.
2.
Change the selected gas (R8) to a custom gas: either
R8=7
or
R8=8
3.
Set the bend factor to the ratio of custom gas mass to nitrogen mass and subtract 0.6
𝐾 =
.
− 0.6
,
R10=#.###
4.
Attach the unit to a vacuum system and pump down below 0.0001 Torr
5.
Zero the instrument by sending the
ZRO
command.
6.
Backfill with the custom gas until the pressure is between 0.1 and 1 Torr as indicated by the pressure
reference.
7.
Set the gas factor to the ratio between the indicated Pirani pressure and reference pressure (G
f
=
P/P
r
):
R9=#.###
8.
Backfill with the custom gas to between 2 and 12 Torr.
9.
Adjust the bend factor by setting K
g
to the reference pressure reading:
SETKG=##.##.
Using
SETKG
alone (without a value) uses the internal Piezo reading as the pressure reference.