Negative Pressure Transmitter

Negative Pressure Sensor

Negative pressure transmitter should be selected according to the measuring medium, use environment, etc. Generally, the material of the sensor contacting medium is 316 stainless steel, which is suitable for measuring various non-corrosive gases, sewage, purified water, oil and other media. Sensors used in corrosive environments must have anti-corrosion properties. The pressure sensitive element of the sensor is made of Hastelloy, Monel, Tantalum and other anticorrosive materials, which can be used in strong corrosive environments such as acid and alkali. The sensor range is generally selected so that the working pressure value is 60% to 80% of the standard range value. The overload pressure caused by the abnormal conditions that may occur in the entire measurement system must not exceed the very large overload allowed by the product. The selection of the negative pressure transmitter should also consider the temperature of the measuring medium and the ambient temperature, the explosion-proof and protection grade, and the accuracy requirements of the product. Sometimes the measuring medium or the impurities contained in it should also consider whether the measuring medium or the impurities will cause blockage.

Since the negative pressure transmitter measures the absolute pressure of the production process, and the general measurement range is very small, to select the pressure gauge range during the selection of the negative pressure transmitter should be stricter than that of the ordinary pressure transmitter, which requires a relatively high accuracy of the process conditions, and then instrument with a very suitable range according to the process conditions should be selected.

Negative Pressure Transducer

After the instrument is selected, its installation is also a very important link. Negative pressure transmitters are mostly used to measure the gas phase pressure of the process medium, so the transmitter should be set higher than the pressure guiding tube. And the mounting brackets are often used to fix the process pipeline or equipment in the second, and the platform is easy to operate. For some reasons, during construction, the importance of the installation of negative pressure transmitters is often ignored.

In this case, it is difficult for the pressure guiding tube to be properly threaded with the instrument. Even if the high temperature sealant is wrapped around the pressure guiding tube and the threaded connection, leakage cannot be prevented, and the instrument cannot be welded to facilitate the maintenance of the instrument. On the pressure guiding tube. If there is a leak, the negative pressure transmitter cannot truly measure the absolute pressure of the production process, so there will be a large error in the reading. This has a particularly prominent impact on the regulation control loop. When the transmitter is not closely connected to the pressure guiding tube and there is leakage, the measured data is not the absolute pressure of the production process at this time, so when the process pressure changes, the measurement results of the transmitter do not change or change inconsistently. The PID function block loses its automatic adjustment function. Therefore, the installation position of the transmitter must be accurately located during the installation of the negative pressure transmitter.