A turbine flow meter is an instrument used for measuring volumetric flow. As liquid flows through a turbine flow meter, the instrument’s rotor spins at a specific rate. When accurate, this rate is consistent and proportional to the volume of fluid passing through the meter. If readings are off, the rate of a turbine flow meter’s rotor is likely not reading properly. Nine times out of ten, this is due to calibration drift.
Just like any other measuring device, a consequence of not calibrating a turbine flow meter is calibration drift. Calibration drift is more common than some think and should not be taken for granted. Turbine flow meters are prone to drifting, especially when other factors play into the process. Below we have listed seven common causes of turbine flow meter calibration drift.
PRESENCE OF DEPOSITS
One cause of turbine flow meter calibration drift is the presence of deposits on the internal surface of the meter. Deposits could be made up of substances such as salt or other minerals. This type of scenario is likely to occur on meters with and without moving parts. Although a turbine flow meter may seem to be functioning properly, it is important to have it calibrated frequently to ensure deposit buildup is minimize. Build of a deposits can severely impact a turbine flow meter’s ability to perform as it should.
Turbine flow meters are also prone to chemical wearing. Chemical wearing of any kind and on any level can affect your turbine flow meter calibration, especially the moving parts. Even the smallest wearing can have a great impact on the movements and overall geometry of a turbine flow meter. With frequent calibration, chemical wearing can be monitored and minimized
Turbine flow meters that have undergone some type of trauma are more likely to drift. Trauma such as an accidental drop or over speeding could have a serious impact on a turbine flow meter. If a turbine flow meter has undergone a form of trauma it is vital to have the instrument calibrated before use. While it may look okay from the outside, chances are something on the inside of the meter could be out of whack.
The age of turbine flow meter matters and can play a serious role in calibration drift. Older turbine meters will change over to due to use. Frequent calibration of a turbine flow meter, especially an older one, will help to keep track of the instrument’s precision and repeatability.
Fluid property also plays a role in turbine flow meter calibration drift. When there are changes in fluid property, the flow of a turbine flow meter is affected. To ensure a turbine flow meter can properly measure the fluid property, it is important to have it calibrated each time the fluid property changes.
Another cause of turbine flow meter calibration drift is due to improper installation of the instrument. A turbine flow meter that has not been installed properly is known to have many reading inconsistencies. To ensure a turbine flow meter is reading properly, calibration should be performed to measure the instruments repeatability.
Environment always plays a role in the functionality of turbine flow meter. Factors such as vibration, temperature, pressure, and electromagnetic interference are known to cause a turbine flow meter to drift. This types of influences cannot be controlled; however, calibration of a turbine flow meter can minimize the effects.