Flowmeter calibration device
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Do flow meters in chemical plants need to be calibrated regularly? Calibration is a hassle, but if not calibrated, it’s unclear whether they are accurate. Let’s discuss this.
The calibration of flow meters on-site usually involves setting them to zero; it doesn’t seem like there’s anything else that needs to be calibrated. I hope experts can provide an answer. . .
Flowmeters used for trade settlement measurements are required to be calibrated by authorized metrological institutions every six months as per regulations; other flowmeters need not be calibrated as long as the process is stable and there are no abnormalities. Moreover, except for orifice plates, calibration is generally not possible in ordinary locations
For online calibration of flow meters, a portable ultrasonic flow meter can be used for calibration.
Meters need to be calibrated regularly, and this should be done at a professional institution. If it is only for participation in control, it can be calibrated by oneself based on experience. During maintenance, use a simple device to perform calibration.
The calibration of a flow meter is a complex calibration procedure. First method: If it is confirmed that the sensor of the flow meter is in good condition, then a simple approach can be used. The instruments required for calibration include a standard cubic tank, a standard portable ultrasonic flow meter, a multimeter, an adjustable power supply, a milliampere meter, a 250-ohm standard resistor, and clean tap water. 1: Check the appearance of the flow meter – it should be clean, the nameplate clear, and the sensing elements free from defects or corrosion. 2: The power supply is standard 24V. 3: Connect the power supply and check the zero-point output of the flow meter (make sure the flow meter is at full flow at this point); if the value is 4 milliamps, no adjustments are necessary. Conversely, adjust the zero point. 4: Full-scale calibration. 5: Check instrument parameters, corresponding to step 1, by recording the instrument data. 6: Five measurements must be taken using the flow meter to record the accurate data. The standard table and the standard cubic tank both record data (by logging the instantaneous flow values). 7: The error range is calculated; if it is less than 0.005, the flow meter can generally be considered qualified. 8: When reinstalling, it is necessary to reset the zero point and full scale in conjunction with the control room. The above steps are carried out under the assumption that the flow meter is installed in accordance with specifications, with any errors resulting from installation taken into account.
Generally, flowmeters that are shipped in large quantities require calibration by a third-party certification body, as this involves financial considerations； If it is for personal use, one can calibrate it by themselves; generally, calibration is done only during maintenance or when problems are detected
Are portable ultrasonic flowmeters useful? What is their accuracy?
Portable ultrasonic devices do not have high precision, making them unsuitable for calibrating flow meters such as electromagnetic and vortex flow meters. Generally, it’s best to do as mentioned on the 7th floor: take it for calibration only when maintenance is required or a problem is detected.
Our company has a calibration system purchased from the United States, which can be used to calibrate mass flow meters and rotameters. If you need calibration, please feel free to contact me. Thank you! !