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2.9. Auxiliary Input Connection
The Hastings 400 Series flow meters provide an auxiliary analog input function. The flow meter
can read the analog value present between pins 5 and 6 on the terminal strip (as shown in
Figure 2-2) and make its value available via the digital interface. The accepted electrical input
signal is the same as that configured for the analog output signal (4 – 20 mA, 0 -20 mA, 0-5 Vdc,
1-5 Vdc, or 0-10 Vdc). Unlike the analog output signal, which is isolated and capable operating
at common mode offsets of over 1000V, the analog input signal cannot be galvanically isolated
from ground potential.
2.10. 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
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
S
Rang
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
i
specified
7 Custom
Not included
i
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