A
dual piston mercury sealed prover is used for flow rates below 50 litre/min
with Sonic nozzles being used for flow rates below 600 litres per minute
and a Transfer Standard laminar flow element for flow rates up to 3600
litres per minute.
All
standards have a large degree of range overlap and a programme of periodic
cross-flow checks ensures a high level of confidence in the standards
used.
Our extensive experience in the thermal mass
flow measurement and control market has enabled us to accumulate a
wealth of knowledge in
the service and calibration of all major manufacturer’s thermal
mass flow instruments. Test gases available are dry filtered air, pure
oxygen free Nitrogen, Helium and Argon. Instruments ranged for other
gases are calibrated by applying the manufacturer’s published
gas correction factor (usually from Nitrogen or Air) calculated from
empirical data or theory based on the thermodynamic properties of the
gas. Although the majority of our work involves
the calibration & test
of electronic thermal mass flow meters & controllers, we are also
able to calibrate the following types of gas flow instruments:
- Coriolis meters
- Variable area meters
(Rotameters)
- Turbine flow meters
- Orifice plate / venturi
flow meters
- Piston provers / bubble meters
Our low differential pressure capability also enables us to
perform pressure drop measurements across primary flow devices
at known flow
rates. This provides valuable flow data on customer artefacts such
as laminar flow elements, orifice plates, sintered discs, filters
and standard leaks.
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