Temperature compensation, pressure compensation – what are these means of compensation?
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What are the specific methods for common temperature compensation in temperature measurement, as well as temperature and pressure compensation for flow rate?
Passing by Xue*, what does temperature compensation mean? Is it due to insufficient device temperature, inaccurate temperature measurement, or deviations caused by difficulties in taking temperature readings?
Based on the characteristics of the media, there is already some experience in compensation as well as relevant databases. Make the corresponding correction according to the compensation formula.
No, it is the temperature that affects the measurement results; therefore temperature compensation is necessary
In other words, the instrument already has built-in temperature compensation; but when this built-in compensation is not sufficient, does one need to manually apply compensation using formulas?
The temperature and pressure compensation for flow rate must be based on real-time measurements, that is, it should be measured along with the flow rate itself. Modern integrated instruments all come equipped with temperature and pressure sensing elements. Then, temperature and pressure compensation calculations are performed directly in the instrument, and the resulting data is that which has been compensated for temperature and pressure. If it is not integrated, temperature and pressure measurement devices can be installed on the throttle component accessories; calculations can be performed using secondary instruments or through DCS configuration.
What you said isn’t entirely correct. There are generally three forms: 1. Compensation is carried out at the module level of the instrument; for example, some bar-type flow meters have functions for measuring pressure and temperature. The pressure and temperature signals are fed into the meter’s module, where they are processed using specific compensation formulas to generate a corrected flow signal that is then sent out. 2. The flow, temperature, and pressure signals are detected separately and fed into a flow computer (usually installed indoors), where corresponding calculations are performed using the formulas and databases of that flow computer. The calibration for this type is relatively high. 3. Same as item 2, but carried out using systems such as DCS/PLC; however, the database functionality may be weaker or absent.
This post was last edited by Concave Blade Hero on 2019-3-2 at 10:48. Temperature and pressure compensation is generally used only in differential pressure flowmeters; it can also be performed using flow integrators or within the system (DCS, PLC) for compensation calculations
What you understand isn’t entirely correct either. It should be said as follows: 1. For those measured as volumetric flow rate, if higher precision is required, temperature and pressure compensation can be applied for gas and vapor types. The liquid level can be temperature-compensated. 2. For those measured as mass flow rate, density compensation can be applied.
Does the liquid level also need to be compensated? A mass flow meter can measure density, without the need for additional compensation. If volumetric flow rate is being measured, it needs to be converted to mass flow rate, and that is when density compensation is required.
This post was last edited by Concave Blade Hero on 2019-3-2 at 10:47. What you said is rather confusing. Put it this way: whether measuring liquids (at pressures above 5 Mpa) or gases, for differential pressure flow meters to provide accurate readings, temperature and pressure compensation is necessary.