Below definitions are interpreted from ISO Guide 99:2007 and other international standards.

 

What is a flowmeter?

It is a flow-measuring device which registers or indicates the amount of fluid passed through it over a period of time.

 

What is a flowmeter calibration?

Flowmeter Calibration is a set of operations which establish, under specified conditions, the relationship between values of quantities indicated by a flowmeter under test and the corresponding values indicated by a reference standard by means of comparison. In this operation the specified conditions include but not limited to:

• Traceability of the reference standard
• Environmental conditions and limits
• Flowmeter under test parameters and settings
• Reference standard parameters and settings
• Flowmeter conditions of use and Calibration factors
• Type of fluid measured and quality
• Measurement Uncertainty Contributions
• Flowmeter Repeatability
• Flowmeter output measurement
• Validity of results

 

What are the types of flowmeter calibrations?

Wet or Flow Calibration – comparison in which fluid flows through both the meter under test and reference standard.

Dry or field calibration – calibration in which fluid doesn’t flow through the meter, only electronics part of the flowmeter is focused on.

 

What is flowmeter verification?

It is the provision of objective evidence that a given flowmeter under test fulfils specified requirements. The difference from calibration is that the above specified conditions may not be taken into account when performing flowmeter verification and this could produce misleading results.

 

What is validation?

Verification in a form of an experiment which confirms that specified requirements of a measurement procedure are adequate for intended use.  

 

Flowmeter Performance drift

It is a slow change with time of a metrological characteristic of a flowmeter. This includes any type of measuring instrument.