How to calibrate flow meter?

Flow meter calibration is critical in ensuring accuracy of measurement in or before industrial settings. No matter liquids or gases, calibration is another guarantee of accurate readings, which subjects to an accepted standard. It also reduces the risks of errors and enhances efficiency involving industries like oil & gas, water treatment, petrochemical, etc.

What is flow meter calibration?

Flow meter calibration refers to adjusting pre-set readings so that they could fall within a certain margin of error. It's possible that meters drift over time for the sake of different operational conditions, causing deviations in measurement to a certain extent. Industries like pharmaceuticals or energy processing prioritize precision than other fields, because even a tiny discrepancy could lead to inefficiencies, wasted raw materials or safety problems.

Calibration executed by either manufacturers or via independent calibration facilities is subject to specific industry standards, such as standards provided by the National Institute of Standards and Technology (NIST) in the U.S. or Van Swinden Laboratory in Europe.

Difference Between Calibration and Recalibration

Calibration means to the first-time adjustment of the flow meter while recalibration involves readjustment after the meter being used over a period of time. The accuracy of a flow meter may decrease for abnormal wear and tear triggered by periodic operation. Regular recalibration is of equal importance to initial calibration in a varying and intricate industrial system.

Recalibration also takes both operational history and environmental effects into consideration.  Both steps shield immense and intricate processing and production from inefficiencies, errors and deviations.

Ways of Flow Meter Calibration

Several methods about how to calibrate flow meters have been established well, according to kinds of fluids and meters. Such methods guarantee flow meters' operation following certain pre-defined standards.

Comparison Between Two Flow Meters

The flow meter to be calibrated is placed in series with an accurate one following certain standards. Readings from both meters are compared when testing a known volume of liquid. Necessary adjustments will be made according to the known accurate flow meter in case there are deviations out of the standard margin. This method could be used to calibrate electromagnetic flow meter.

Gravimetric Calibration

A certain quantity of fluid during a set time period is weighed, then comes to comparison between the reading and the calculated outcome. An aliquot of fluid is placed into a test meter then weigh the fluid over a known unit time like sixty seconds. Calculate the flow rate simply through dividing the volume by time. Make sure whether the discrepancy between calculated outcome and the reading fall within allowed margin. If not, adjust the meter and leave the reading in an accepted range. The method is used to calibrating mass flow meter.

Piston Prover Calibration

Piston prover calibration is suitable for calibrations of air flow meters, utilizing a piston with a known internal volume to force a specific amount of fluid through the flow meter. Measure the volume of fluid going forward to the piston prover. Then compare the displayed reading with the known volume and adjust accordingly if necessary.

Significance of Regular Recalibration

The accuracy of a flow meter may degrade over a period of time in immense and intricate processing systems like pharmaceuticals, aerospace, energy and water treatment. Profit loss and equipment damage may be incurred by inaccurate flow measurement, which produce direct effects on costs and profits.

Flow meters used to detect system leaks may not offer precise enough readings to accurately identify leaks or equipment malfunctions, such as those commonly found in the oil and gas industry or municipal water systems.

Challenges Facing When Calibrate a Flow Meter

Calibrating flow meters can come with challenges, such as variations in fluid properties, temperature effects, and environmental changes. Additionally, human error during manual calibration can introduce inaccuracies. Automation and advanced software tools are increasingly used to improve calibration accuracy, offering real-time feedback and adjustments based on operational data.