401-405 SERIES
- 12 -
2.2. Rotary Gas Selector
The Hastings 400 Series flow meters can have up to eight different calibrations
stored internally. These are referred to as gas records. These records are used
to select different gases, but they can also be useful in other ways; for instance
reporting the flow in an alternate range, flow unit or reference temperature.
The records are referred to by their number label from #0 – #7.
The first six records will, by default, be setup for most common six gases as
shown in Figure 2-11. If a gas other than one of these six is specified on the
customer order it will be placed in record #6. If a second different gas is
selected, it will be placed in record #7. If multiple different gases or ranges are
specified they will replace some of the standard six gases.
The purchased calibration certificate is provided for the gas (or
gases) specified by the customer when ordering. This gas will be
indicated with an “X” on the Gas Label (diagram below) that is
located on the top of the 400 Series Mass flow meter’s electronics
enclosure. The remaining gas records will have a different full scale
value and an unverified calibration. The full scale range
can be calculated by using the Gas conversion factor or
GCF. A comprehensive list is found in Appendix 2 in
this manual.
Example 1
To convert the calibration of a full scale range of 100 slm of Nitrogen to the other full scale ranges:
1. Calculate full scale value of Helium
Calibrated gas = Nitrogen (GCF
1
= 1.000)
Full scale range (FS
1
) = 100 slm
Secondary gas (FS
2
) = Helium (GCF
2
= 1.40)
1.40/1 = 1.40, 1.40 x 100 = 140 slm of Helium
2. Calculate full scale value of Hydrogen
Calibrated gas = Nitrogen (GCF
1
= 1.000)
Full scale range (FS
1
) = 100 slm
Secondary gas (FS
2
) = Hydrogen (GCF
2
= 1.0038)
1.0038/1 = 1.0038, 1.0038 x 100 = 100.38 slm of Hydrogen
Record# Gas
0 Nitrogen
1 Air
2 Helium
3 Hydrogen
4 Argon
5 Oxygen
6 Custom
7 Custom
Figure 2-11 Gas record table
Record# Gas
Full Scale
Range
0 Nitrogen
100 slm
1 Air
100.15 slm
2 Helium
140 slm
3 Hydrogen
100.38 slm
4 Argon
140.37 slm
5 Oxygen
97.95 slm
6 Custom
Not included if
not specified
7 Custom
Not included if
not specified
1
2
12
GCF
GCF
FSFS =
0
1
2
3
N
Air
He
H
4
5
6
Ar
2
O
2
7
X= cal report
generated
(others use GCF)
S/N
2
X
