Sigma Test and Research Centre : Laboratory Testing,Quality Control,Testing Services
    • Fluid Flow Calibration

Sometimes the highly pitted flowmeters fall out of calibration. Over time, the performance of all the instruments depreciates with numerous wear and tear. The flow of the media through the flowmeters can be affected by corrosion and dirt. Temperature variations may also damage during the process.

With the potent measurement of fluid flow and the process by the conditions of use all the measurement devices are influenced. The situations under which the meter will be in practice may have an impossible standard.

To define a set of operations , together with influence factors, the standard, the device and the combinations of fluid are used to provide the calibration. Meaningful prospect of how the device will function when in use is expressed in such way.

Sigma is fully equipped with instruments like Reference Flow Monitor and Laminar Flow Monitor, for the calibration of Rotameter and Mass Flow Meter.

Rotameters are widely used in process industries.

Fluid Flow Calibration


Rotameters are used in systems that involve a liquid or gas travelling through a tube.

For example, rotameters are used in oil pipelines to measure the flow rate of oil as it is dispersed from one location to another across great distances. Portable rotameters can also be constructed to measure the flow rate of large bodies of liquid or gas, such as rivers, oceans, streams, as well as the atmosphere. These portable rotameters can simply be dunked into the substance they are measuring in order for a measurement to be taken.

Use in an Orifice Bypass

To cost-effectively handle larger flow rates of liquids or gases, a rotameter can be installed in a bypass line around an orifice plate. The differential pressure produced by the orifice causes a relatively low flow through the rotameter that can be a measure of flow through the main pipeline.Key benefits include:

  • Usefulness where the measurement must be made in a hazardous or remote area, or where electric power is either not available or would be potentially dangerous
  • Rangeability that can be 121/2:1, as compared to 4:1 for dp meters
  • Scale readings that can be graduated in direct units for flow in the main pipeline
  • Changing the range or cleaning the tube without disassembling the meter or removing it from the bypass line.

Calibration of rotameter is essential

  • The standard that you use to calibrate a flowmeter must be accurate enough to perform the calibration. The general rule of thumb is that your standard should be four times more accurate than the unit under test (UUT); however, this can vary depending on the requirements of the calibration.
  • Your standard should be traceable to a recognized standard. Traceability provides an unbroken chain of documentation that shows how the measurements it makes compare to even more accurate standards. Traceable measurements help you prove that your measurements are what your flowmeter says they are, within specific ranges.
  • The rate of flow between the UUT and the calibration standard must be in a steady state. Since the flow rate of the standard and the UUT are compared in real time during calibration, the system flow rate should not vary with time.
  • All media measured by the calibration standard must also be measured by the flowmeter at the same time. In other words, there should not be any leaks or significant temperature changes in intermediary volumes that might affect the measurement.
  • You should perform the calibration under conditions that are typical of the flowmeter’s actual operation. For example, the viscosity, density or heat content of the liquid being measured can affect the flowmeter based on its operating technology. It is important to match the calibration with the flowmeter’s application.