ON SITE FLOW VALIDATION

Flowmeters are supplied in many formats to industries such as Water, Wastewater, HVAC, Mining, Gas, Medical, agriculture and pharmaceuticals. They are primarily designed to measure the velocity of fluid and or gas. The volume is then calculated by the meter incorporating the physical dimensions, pipe wall, and diameter of the pipe. Most flow meters are designed to maintain accuracy for many years but many factors contribute to loss of accuracy, drift and even failure. Poor installation, dirt, corrosion, wear, scaling, media flowing in the pipe, process changes all impact the stability and accuracy of the meter. Regular calibration checks and verification assure the user that the flowmeters have maintained accuracy as per specifications.

Calibration Basics

  1. The test meter being used should be more accurate than the MUT (Meter Under Test) – normally under lab conditions.
  2. The meter must be traceable to a recognized standard. Traceable measurements confirm that test results are, within specified ranges.
  3. The system flow rate, temperature, pressure, viscosity, density should be maintained
  4. The test meter must also have a high degree of repeatability across a wide range of flow conditions.

Why is a calibration required?

The decision to check or calibrate a meter could be a result of a number of factors.

  • Sudden change in flow profile or damaged meter.
  • Uncertainty about accuracy of existing meter.
  • 3. Legislation where local authority requires regular calibration
  • Quality control and confidence that existing meters are within specification
  • Disputed or irregular flow volumes or flow patterns