Temperature and pressure compensation

Vortex flow meters, turbine flow meters, and orifice plate flow meters all require pressure and temperature compensation

In actual operating conditions (pressure, temperature), these values are unlikely to remain stable; therefore, pressure or temperature compensation is necessary. The general principle is PV/T = constant, but it is also normal to use more accurate formulas for certain substances that deviate from ideal gas behavior. For media with stable pressure or temperature, it is sufficient to directly adjust the calculation formula; no compensation is required.

In fact, it is quite difficult to design and implement corrections for flow rate on one’s own; it is possible to use a mass flow meter, which comes equipped with correction functions and measures flow based on mass rather than volume.

When the density of a medium changes with temperature and pressure, temperature and pressure compensation is required.

Thank you, ours is a mass flow meter

Thank you to all the experts. I wonder why some flowmeters require temperature and pressure compensation when measuring gas flow, while others do not need such compensation. Is there something specific regarding the gas being measured that determines this?

Apart from those that are actually operating in the set working mode of the instrument, which ones don’t require compensation? I’m not sure how far you’ve gotten in your studies, but instruments that don’t require compensation are those for which either the environment differs little from the standard operating conditions, or the instrument itself has already incorporated compensation mechanisms. Strictly speaking, all instruments used in practical applications require compensation; however, in practice, reasonable errors are used in place of such compensation. For truly precise measurements, environmental changes must be taken into account, and even before each use, the instrument’s condition needs to be adjusted

When it comes to measurement, the first thing to consider is not the compensation provided by the compensation unit, but rather the measurement error permitted in the application. First, determine the allowable error, and then choose an appropriate measurement method based on it.

This post was last edited by ylb913 on 2016-9-20 at 22:10. Based on the principles of flow measurement, this applies to those instruments whose flow readings are affected by changes in pressure and temperature (that is, flow meters in which the signal measured by the instrument needs to be converted into a flow value using the medium’s pressure and temperature), and where the actual pressure and temperature often deviate from the conditions specified during design. So far, I only know that mass flow meters are not affected by actual pressure and temperature, while the flow rates indicated by other flow meters are related to pressure and temperature. All of this is related to the pressure and temperature assumed under design conditions; any deviation of the actual operating pressure and temperature from those specified in the design will affect the accuracy of measurement.