Series Max. Flow 10, 50 And 100 L/Min; Calibration Procedures; Flow Calibration - Omega FMA 5400A User Manual

7.

CALIBRATION PROCEDURES

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NOTE: Removal of the factory installed calibration seals and/or any
adjustments made to the meter, as described in this section, will void
any calibration warranty applicable.
7.1

Flow Calibration

OMEGA ® Engineering Flow Calibration Laboratory offers professional calibration
support for Mass Flow Meter and Controllers, using precision calibrators under
strictly controlled conditions. NIST traceable calibrations are available.
Calibrations can also be performed by customers using available certified stan-
dards.
Factory calibrations are performed using state of the art NIST traceable precision
volumetric calibrators.
Calibrations are performed using dry nitrogen gas. Calibration can then be cor-
rected to the appropriate gas desired based on relative correction [K] factors
shown in the gas factor table - see Appendix 2. A reference gas, other than nitro-
gen, may be used to approximate the flow characteristics of certain gases closer.
This practice is recommended when a reference gas is found with thermodynamic
properties similar to the actual gas under consideration. The appropriate relative
correction factor should be recalculated - see section (9).
It is standard practice to calibrate Mass Flow Controllers with dry nitrogen gas. It
is best to calibrate the FMA Series Max. Flow 100 L/min transducers to actual
operating conditions. Specific gas calibrations of non-toxic and non-corrosive
gases are available at specific conditions. Please contact OMEGA7 for a price
quotation.
It is recommended that a flow calibrator of at least four times better collective
accuracy than that of the Mass Flow Controller to be calibrated be used.
Equipment required for calibration includes a flow calibration standard and a cer-
tified high sensitivity multimeter (which together have a collective accuracy of
±0.25% or better), an insulated (plastic) screwdriver, a flow regulator (example:
metering needle valve) installed upstream from the Mass Flow Controller and a
pressure regulated source of dry filtered nitrogen gas (or other suitable reference
gas).
The gas and ambient temperature, as well as inlet and outlet pressure conditions
should be set up in accordance with actual operating conditions.
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