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. For information about calibrating for Hydrogen or 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:
Cf = ( Snew ÷ Scurrent )0.3
Cf = Correction factor
Snew = Specific gravity of new gas
Scurrent = Specific gravity of original calibration gas
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 (CO2) with a specific gravity of 1.517 the flow reading correction factor would be calculated as follows:
Snew = Specific gravity of CO2 = 1.517
Scurrent = Specific gravity of Air = 1.000
Cf = (Scurrent ÷ Snew)0.3
Cf = ( 1.000 ÷ 1.517 )0.3
Cf = 0.88
pg. 14 of 29
