Zero Adjustments; Recalibration; Using Flow Sensors Or Flow Meters With Different Gases - Omega Engineering FLR 1000 Series User Manual

4.

Zero Adjustments

It is impossible for there to be any zero drift so zero adjustments are
never required.
5.

Recalibration

Please contact the Omega Engineering Service Department if your flow
sensor or flow meter needs recalibration.
6.

Using Flow Sensors or Flow Meters with Different Gases

The FLR 1000 Series will operate with most gases subject to compatibility
of the wetted parts.
Helium, contact the Omega Engineering Service Department.
Units are calibrated with AIR at a pressure of 760mmHg and temperature
of 23°C unless otherwise detailed on the calibration certificate. Using other
gases will effect the calibration. The amount of calibration error will
depend on the characteristics of the gas being flowed.
The flow reading correction factor (or calibration factor) may be
approximately calculated with the following formula:
C
f
C = Correction factor
f
S
new
S
current
A corrected flow reading may then be calculated using the correction
factor as follows:
Corrected Flow = Flow reading X Correction Factor
For example, if the unit is calibrated for AIR but the user wants to
measure the flow of Carbon Dioxide (CO
the flow reading correction factor would be calculated as follows:
S
new
S
current
C
f
C = ( 1.000 ÷ 1.517 )
f
C = 0.88
f
For information about calibrating for Hydrogen or
= ( S ÷ S
new current
= Specific gravity of new gas
= Specific gravity of original calibration gas
) with a specific gravity of 1.517
2
= Specific gravity of CO
= Specific gravity of Air = 1.000
= (S ÷ S )
current new
0.3
0.3
)
= 1.517
2
0.3
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