Integrated component RS5484 for measuring fan vibration

For high temperature and pressure resistance under vacuum or low temperature measurement conditionstransmitterDue to its short service life or low measurement accuracy, it has not been fully utilized. This article focuses on analyzing the factors that affect the normal operation of high-temperature pressure transmitters and proposes an application plan for high-temperature pressure transmitters used in vacuum or low-temperature environments.

(1) Fully welded pressure transmitter. All connections between capillaries, transmitters, and process connections are fully welded sealed structures to eliminate potential leakage points.

(2) According to different applications, the amount of filling oil can be controlled. Based on the user's application and the characteristics of different filling oils, after careful calculation, the amount of filling oil should be appropriately reduced to compensate for the expansion effect of filling oil. For low-temperature applications, the amount of filling oil can be appropriately increased according to the specific application to compensate for the effect of filling oil volume shrinkage.

(3) Special oil replenishment and drainage treatment. The main purpose of oil pretreatment for filling oil is to reduce the content of dissolved gases. During the oil filling process, vacuum oil filling is used, and the oil filling amount is strictly controlled when the oil reaches the required vacuum degree to ensureproductMeasurement accuracy.

(4) In modern manufacturing processes, high-temperature pressure transmitters often adopt symmetrical designs, with the same diaphragm, capillary length, and oil filling fluid at both high and low pressure ends. It is generally believed that the effect of temperature changes on the high and low voltage sides of the transmitter will be eliminated. The effect of temperature on the diaphragm is generally considered an important cause of temperature drift. In fact, the situation is exactly the opposite.

Using capillaries of the same length on the high and low pressure sides did not improve performance, but instead increased the impact of temperature changes on the overall performance of the transmitter. The pressure transmitter depends not only on the temperature change of the base product diaphragm, but also on the length of the capillary tube, which is an important factor affecting the temperature change of the transmitter. The hardness is directly proportional to the length of the capillary tube.

The high and low pressure sides use the same capillary length, which is twice the length of the capillary, thereby increasing the impact of temperature on the overall performance of the transmitter. That is to say, if the process temperature is 150 ℃ or lower and the process conditions permit, the dismantling shall be carried outhigh pressuresideportConnecting the capillary tube directly to the transmitter can shorten the length of the capillary tube and reduce the impact of temperature changes on the accuracy and corresponding time of the transmitter.

(5) Choose according to the different chemical properties of the measured medium. The corrosiveness of the same medium with different concentrations varies at different temperatures. Diaphragm sealed pressure transmitters generally use stainless steel material for the inner membrane box, and the outer membrane box for liquid connection is selected according to the characteristics of the medium. The commonly used materials currently include 316L, Monel, Hafnium alloy, and Tan film. Consider the material of the pressure transmitter housing based on environmental conditions and economy. The housing materials generally include aluminum alloy and stainless steel. If it is not in a highly corrosive environment, choosing aluminum alloy material is more economical.