The operating conditions of the flow meter directly affect its metering performance.The most direct impact of operating pressure or temperature changes on the flow meter is the change in its metering chamber. The indirect influence of the electromagnetic flow meter is the change of physical properties such as viscosity and density of the measured medium, but the indirect influence can be considered when correcting the influence of physical properties. Due to the complexity of the structure and shape of the flow meter and the discreteness of the processing assembly, it is almost impossible to accurately correct the change of the cavity with the operating conditions by using the calculation method, and it is impossible to fit the empirical formula that satisfied accuracy requirements for all the flow meters according to the test data.
Turbine flow meter for volumetric flow meters, When carrying out the type identification, prototype test or quality inspection of flow meters,after the natural aspirated engine was converted to a turbocharged engine,whether it is an exhaust turbocharger or a mechanical supercharger will encounter the problem of high intake air temperature.
For vortex flow meters, the temperature of the compressed air is definitely higher than that of the uncompressed.The intake air temperature of a naturally aspirated engine does not change much regardless of the state of the engine,whether it is installed in the air flow meter, or on the intake manifold not far from the throttle or at the wind partition, there is little difference;
For a speed turbine flow meter, changes in operating conditions will cause a change in its flow area, resulting in a change in meter factor.If the operating conditions of the flow meter during verification can be the same or close to the actual use,the offline verification can meet the requirements.However, due to the complexity and variability of operating conditions, offline verification often fails to reproduce the actual operating conditions. Only online real-flow verification can solve the problem of high-accuracy flow measurement,otherwise additional errors should be considered.