A flow meter quantifies the speed at which gas or fluid moves across it. Professionals who specialize in testing and measuring often rely on flow meters wherever the measurement of accurate flow is imperative. There is a wide range of applications (not limited to) such as utilities, energy, HVAC, agriculture, aerospace, the pharmaceutical industry and clean water production. In all these applications, accurate calibration of a flow meter to make necessary measurements is vital. Consistent calibrations ensure that the flow measurement is giving measurements, which are correct and in sync with the listed specifications.
What is calibration and why is it so important?
When engineers and scientists talk about calibration, they are referring to traceable standards to correct or establish specific factors to an individual flow meter. The calibration process requires that the meter tested is matched with the master standard flow meter in the laboratory.
Flow meter calibration is vital to obtaining precise and consistent flow measurements. An exact flow measurement is what is required in some crucial processes that occur all around the world such as transferring fuel to a different custody, producing clean water and generating electricity.
However, it is important to note that even high precision flow meters can easily deter from calibration. Similar to technological gadgets, the performance of all flow meters reduces over time. Parts may break down or wear out. Flow meters are also affected by dirt from the media that flows across them as well as corrosion. A flow meter can become easily damaged from impact, improper installation, and variations in procedures.
What are some standard best practices of flow meter calibration?
Standard best practices of flow meter calibration ensure that the measurements obtained from testing are accurate and reliable. The process of calibration is applicable for all test equipment, not just flow meters.
Flow meter calibration has best practices, which help to ensure accuracy. These are:
- The standard used to calibrate the flow meter must be precise enough to undergo calibration. The rule of thumb is that the standard must be at least four times more exact than the unit under test or UUT. However, keep in mind that this will vary according to the requirements of the standardization.
- The standard you use ought to be traceable to a documented standard. It is known as traceability, and it provides a continuous trail of documentation that proves how the measurement it generates compares to accurate standards. A traceable measurement helps prove that your measurements are exactly what your flow meter says they are.
- The rate of flow between the calibration standard and the unit under test should be in a stable state. The flow rate of the UUT and the standard are related in real time during standardization; therefore the system flow must not vary with time.
- All media that is measured by the calibration standard should also be calculated by the flow meter, at equivalent times. No significant temperature changes or leaks in intermediate volumes can occur as these will impact measurement.
- Calibration should occur under conditions that are similar to the flow meter’s actual operation.
Calibration of a flow meter is necessary to obtain accurate measurements.