Table of Contents
Advertisement
Instruction Manual
IG + CG1 analog output correction factors for selected gases
7.3.2
When using the IG + CG1 analog output mode (Log-Linear 0.5 - 7 V, 0.5 V/decade) for gases other than N
the analog output is interpreted differently over two different pressure ranges as discussed below:
A) Pressure range from the 1.0 x 10
Use the information and equation described in
7.3.2.1
below to determine pressure from the voltage for selected gases (ion gauge range).
B) Pressure range from 1.0E-03 to 1,000 Torr:
Use the correction factors listed in
selected gases (convection gauge range).
7.3.2.1
IG + CG1 analog output correction factors - Ion gauge range
A) When using the IG + CG1 analog output mode (Log-Linear 0.5 - 7 V, 0.5 V/decade) for gases other than
N
/ Air, use the following steps to convert the analog output to pressure when operating in the pressure
2
range of 1.0 x 10
B) Refer to
section 6.2
pressure. This pressure value is based on nitrogen.
C) Apply the sensitivity correction factor for the particular gas you are using to the pressure value obtained
in step A (Use correction factors and example listed below).
Gas
He
Ne
D
2
H
2
N
2
Air
O
2
CO
Example:
The gas in use is argon. Output voltage is 3 volts. Pressure unit is Torr.
����������−5.5
P (nitrogen) =
10
0.5
−��
�� ����
P (argon) =
=
��. ���� × ����
��.����
The same correction factor must be applied over the entire pressure range as measured by the ion gauge.
InstruTech
-9
Torr to 1.0E-03 Torr:
section 7.3.2.2
-9
Torr to 1.0E-03 Torr.
and related equation to convert the voltage in your receiving instrument to
Ion Gauge Gas Correction Factors for selected gases
Gas
Correction Factor
0.18
0.30
0.35
0.46
1.00
1.00
1.01
1.05
(3.0 – 5.5) / (0.5)
= 10
, P =
1 × 10
−��
Torr true pressure of argon gas
section 6.2
and the correction factors listed in
below to determine pressure from the voltage for
Gas
H
O
2
NO
Ar
CO
2
Kr
SF
6
Xe
Hg
−5
Torr (based on nitrogen)
IGM402 Hornet
Gas
Correction Factor
1.12
1.16
1.29
1.42
1.94
2.50
2.87
3.64
/ Air,
2
section
Page 53
Advertisement
Table of Contents
Troubleshooting
