Sponsored Links

Accuracy indicates how close the measured value is to the accepted or true value.

The accuracy of flowmeters can be stated as:

• percent of full span
• percent of rate

Accuracy as Percent of Full Spann

Accuracy in percent of full span can be expressed as:

a_% = a 100% / s         (1)

where

a_% = relative accuracy (%)

a = +/- absolute accuracy

s = full scale of the flowmeter

Example - Accuracy of Flowmeter in Percent of Full Span

If the absolute accuracy is +/- 10 kg/h - the relative accuracy at full scale 1000 kg/h can be calculated as:

a_% = (+/- 10 kg/h) 100% / (1000 kg/h)

    = +/- 1%

The relative accuracy at full scale 100 kg/h can be calculated as:

a_% = (+/- 10 kg/h) 100% / (100 kg/h)

    = +/- 10%

Accuracy as percent of Rate

Accuracy in percent of rate can be expressed as:

a_% = a 100% / q         (2)

where

a_% = relative accuracy (%)

a = +/- absolute accuracy

q = flow rate

Example - Accuracy of Flowmeter in Percent of Rate

If the relative accuracy is +/- 1% of rate - the absolute accuracy at rate 1000 kg/h can be calculated as:

a = (+/- 1%) (1000 kg/h)

    = +/- 10 kg/h

The absolute accuracy at rate 100 kg/h can be calculated as:

a = (+/- 1%) (100 kg/h)

    = +/- 1 kg/h

Sponsored Links

Related Topics

• Fluid Flow Meters - Flow metering basics - Orifice, Venturi, Flow Nozzles, Pitot Tubes, Target, Variable Area, Positive Displacement, Turbine, Vortex, Electromagnetic, Ultrasonic Doppler, Ultrasonic Time-of-travel, Mass Coriolis, Mass Thermal, Weir V-notch, Flume Parshall and Sluice Gate flow meters and more

Related Documents

• Flowmeters and Turndown Ratio - An introduction to turndown ratio for flow measurement devices as orifices, venturi meter etc.
• Types of Fluid Flow Meters - An introduction to different types of fluid flowmeters - Orifices, Venturies, Nozzles, Rotameters, Pitot Tubes, Calorimetrics, Turbine, Vortex, Electromagnetic, Doppler, Ultrasonic, Thermal, Coriolis