1. Laboratory calibration

• Standard device: Use standard flow meters (such as turbine flow meters, mass flow meters) in series with float flow meters to compare readings.
• Calibration medium: Consistent with the actual working condition medium (such as calibrating liquid flow meters with water and gas flow meters with air).
• Calibration points: Covering 20%, 40%, 60%, 80%, and 100% of the measuring range, record the error curve.

example
The calibration results for a float flowmeter with a range of 0-10 m ³/h and a level of 1.5 are as follows:

Conclusion: The error of this flowmeter exceeds the standard (>1.5%) at low flow rates (2 m ³/h), and the float needs to be adjusted or the usage range limited (such as only used for 4-10 m ³/h).

2. On site calibration

• Weighing method: Measure the mass of the medium flowing through a certain period of time and infer the volumetric flow rate.
  Steps:
  1. Close the downstream valve of the flowmeter and drain the pipeline;
  2. Turn on the flow meter and start the timer at the same time;
  3. Collect fluid for a certain period of time (such as 10 minutes) and weigh it;
  4. Calculate actual flow rate: Q=ρ× tm (where m is mass, ρ is density, and t is time).
• Comparison method: Compare the readings with other high-precision flow meters (such as electromagnetic flow meters) on site to correct the errors of the float flow meter.

3. Automatic compensation of intelligent flow meters

partIntelligent float flowmeterEquipped with temperature and pressure sensors and a microprocessor, it can automatically correct errors such as changes in medium density and installation tilt, with an accuracy of ± 0.5% FS.