Depending on your industry, your application, and the environment in which your meter operates, you may require flow meter calibration and maintenance more, or less, frequently than others. While calibration drift can be caused by many factors such as the flow meter type and the environment in which it operates.
Here are some of the most common reasons for calibration to drift; some of which you can avoid, others that you can’t. For those that can’t be avoided, you will want to send your flow meter in for calibration.
Deposits on internal surfaces of the meter such as salt or other minerals. This can occur on meters with and without moving parts. Even if everything seems to be working properly, this can severely impact your meter’s ability to perform as it should.
Chemical wearing on any level can affect your flow meter calibration, especially flow meters with moving parts as the small wearing can greatly affect the movements and overall geometry of your meter.
Abuse of the meter. This can be either an accidental drop of the meter, over speeding, etc. The meter may seem ok on the outside, but its performance could have been compromised.
The age of your meter. Older meters will have changed from their original performance due to use, wearing, electrical changes and other factors over time.
Changes in fluid property. If your meter was calibrated in one type of fluid and used in another type of fluid you may see a difference in performance. A change in fluid property can and will affect all types of flow to some extent but it is possible to make corrections to compensate for these changes.
Your flow meter may not have been installed properly and this can lead to major inconsistencies in operation.
External influences will always effect your flow meter calibration and performance regardless of what kind of meter you have. Factors such as vibration, temperature, pressure, electromagnetic interference, etc.
When your flow meter calibration and performance does shift, it is important to make sure you take the necessary actions to correct the problem. This may mean adjusting your processes or, for a more reliable solution, sending the meter out for re-calibration by an accredited lab.