How to choose a FUJI FKB pressure transmitter
A pressure transmitter is a field instrument that is in direct contact with the measured medium. Pressure transmitters usually work in high temperature, low temperature, corrosion, vibration and shock environments. Therefore, when selecting a pressure transmitter, in addition to considering the measurement range and accuracy that the general instrument needs to consider, the working environment and the measured medium are also one of the important indicators.
Pressure transmitter measuring range
Generally, the Fuji pressure "differential pressure" transmitter has a certain adjustable range. Set the range used in the 1-3 to 2-3 range of its range to determine accuracy, which is more important for differential pressure transmitters. Determining the value of the measured pressure in a system typically requires selecting a transmitter with around 1.5 times the pressure. This is mainly in many systems, especially in water pressure measurement and processing, with peaks and continuous irregular fluctuations. Such momentary spikes can destroy the pressure sensor. Therefore, snubbers can be used to reduce pressure glitches, but will slow down the response of the sensor. Therefore, when selecting a pressure transmitter, fully consider the pressure range, accuracy and stability.
Accuracy level of pressure transmitter Accuracy is the key performance indicator of any process measurement equipment, and it is also an important factor to be considered in equipment selection and maintenance. According to the measurement range and the error allowed by the process, first select the range, and then calculate the allowable reference error of the instrument according to the error allowed by the process, delete the ± sign and %, and its value is the accuracy. Without this class, the accuracy class (to high precision) will be relied on. Pressure and differential pressure transmitters are marked with different accuracy classes from country to country. For example, in countries such as China and the United States, the accuracy of the target is the part with good linearity of the sensor, which is what we usually call the accuracy of the measurement range between 10% and 90%; the accuracy of the European target is the part with the worst linearity, That is, the accuracy of what we usually call measurement inverse is 0~10% and 90%~100%. For example, the European standard accuracy is 1%, while the Chinese standard accuracy is 0.5%.
At present, the accuracy index of most differential pressure transmitters is 0.1% or 0.075%, and the high precision index is 0.05% or 0.025%. However, the mentioned accuracy is only an indicator provided by the manufacturer of the differential pressure transmitter. When ordinary users make real use in the field, if it is represented by the integrated function error value, only the integrated function error value of individual real programs may reach the index value provided by the manufacturer. In most cases, the two are quite different. The main reasons for the interference accuracy in real use are the interference of the full scale ratio, the interference of the ambient temperature to the 0 point, the interference of the ambient temperature to the full scale, the interference of the pressure to the 0 point and the interference of the pressure to the full scale. The pressure transmitter only needs to fully consider the interference of the ambient temperature and the full scale ratio, while the pressure transmitter needs to fully consider all the interference.
In addition, the factors that affect the accuracy of the pressure transmitter also include the influence of the power supply, the influence of vibration, the influence of the installation position, etc., but these factors are relatively small and need to be considered according to actual needs.
