Using The Gauge With Different Gases - Instrutech Hornet User Manual

Instruction Manual
6

Using the gauge with different gases

InstruTech gauge transducers and modules are calibrated for nitrogen gas.
Read the following information very carefully if you intend to use a gas other than nitrogen or air.
The IGM401 offers the user the choice to use the factory default gas type N
commonly used gases in the menu.
1) Selecting a specific gas other than nitrogen
If a specific gas other than N
factor to the measurement. The specific gas symbol will also be displayed along with its measurement value. In
this case no correction factor needs to be applied to the IGM401 measurements. The user must ensure all
operators are aware the display measurement represents the true measurement value specific to the selected
gas.
2) Using nitrogen as the default gas
If you intend to use nitrogen as the default gas even though the gas in use is not nitrogen, you can select N
(nitrogen) from the menu, but you must manually apply a gas sensitivity correction factor to the displayed
measurement and analog output. Post a label on your ion gauge display showing the correction factor if you
intend to select nitrogen as the gas and apply manual correction factors verses selecting specific gases from the
menu. The following table provides some typical correction factors. To correct the measurements, divide the
measured pressure by the correction factors:
Gas
He
Ne
D
2
H
2
N
2
Air
O
2
CO
Example:
A) The IGM401 is selected for nitrogen. The gas in use is argon. The measured pressure is displayed at
-6
1.00 x 10 so the actual pressure of argon is:
−��
��.�� ����
��. ���� × ����
P (argon) = =
��.����
The correction factor must be applied to both the display and analog output over the entire pressure range
measured by the ion gauge.
InstruTech, Inc.
is selected from the menu, the IGM401 will automatically apply the conversion
2
Gas Sensitivity Correction Factors
Sensitivity
Correction Factor
0.18
0.30
0.35
0.46
1.00
1.00
1.01
1.05
−��
Torr true pressure of argon gas
or select from a table of 16 most
2
Gas Sensitivity
Correction Factor
H O 1.12
2
NO 1.16
Ar 1.29
CO 1.42
2
Kr 1.94
SF 2.50
6
Xe 2.87
Hg 3.64
IGM401 Hornet
2
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