Fault analysis during the inspection of the measuring part of the pressure transmitter
Pressure transmitters are primarily composed of human like sensors, electronic displays, and connectors. They can replace human labor to achieve mechanization and automation in production, and can be operated in harmful situations to maintain personal safety. They are widely used in mechanical manufacturing, electronics, light industry, and atomic energy. With the miniaturization and microminiaturization of transmitters, their usage scope will break through the traditional mechanical category. Pressure transmitters are developing towards industries such as electronic information, biotechnology, life sciences, and aerospace, which require the skills of fine transmitters to be strong enough to meet the requirements of the times. Driven by rapid economic growth, China's pressure transmitter industry has grown rapidly, with its total production volume ranking at the forefront of the world. Although there is still a certain gap in the overall level of planned manufacturing compared to developed countries, it has become a major producer of pressure transmitters in the world, and now we should be happy to move towards the goal of becoming a strong country.
The working principle of a pressure transmitter: When the pressure value of the measured medium is directly applied to the diaphragm of the sensor, the diaphragm will produce a micro displacement proportional to the medium pressure, causing the resistance value of the sensor to change. The electronic circuit is used to check the changes and convert them into a standard measurement signal corresponding to the pressure value.
Image of pressure transmitter
Fault analysis during the inspection of the measuring part of the pressure transmitter:
With the development of various industries such as aerospace products, information electronics, materials, and electrical engineering, as well as the demand for various pressure transmitters, pressure transmitters have ushered in a huge development space. At present, companies and enterprises producing pressure transmitters are spread all over the country, producing many specifications, models, and series of products. Some pressure transmitter products have been exported abroad, reaching markets in Asia, Europe, and America, with certain competitiveness.
Malfunctions in the measuring section of a pressure transmitter can cause the transmitter to have no output or abnormal output, so the following should be checked first:
1. Remove the flange and inspect the sensitive component isolation diaphragm of the transmitter for deformation, damage, and oil leakage.
2. Remove the compensation board without removing sensitive components, and check the insulation resistance of the pressure transmitter pins to the housing. The insulation resistance should not be less than 100M Ω when the voltage does not exceed 100V.
3. Connect the circuit and gas circuit of the pressure transmitter. When the pressure signal reaches the upper limit of the range, turn off the gas source, and the output voltage and reading value should remain stable. If the output voltage drops, it indicates that the transmitter has a leak. You can use soap water to check the leak location.
Suitable environmental conditions for pressure transmitters:
1. The pressure transmitter operates at a temperature range of -10~80 ℃. If the temperature is high, a heat pipe device should be used to dissipate heat.
2. The usage environment for precision measurement has also been studied. 0.5% F.S is the most widely used value, while 0.25% F.S is a typical value that can make the measurement medium more accurate.
3. The measuring medium of the pressure transmitter will vary depending on the measured medium, and the acid and alkali resistance of the product.
4. The range pressure is generally 1.5 times the overload capacity. When using a secondary instrument, the received output signal should be considered.
5. Customize and install corresponding size requirements based on the customer's interface size.
A pressure transmitter is a hydraulic electrical conversion component that uses the pressure of a liquid to open and close electrical contacts. The electrical component that senses pressure in a pressure transmitter is generally a resistance strain gauge, which is a sensitive device that converts the pressure on the measured object into an electrical signal. The most commonly used types of resistance strain gauges are metal resistance strain gauges and semiconductor strain gauges. There are two types of metal resistance strain gauges: wire strain gauges and metal foil strain gauges. Usually, strain gauges are tightly adhered to a mechanically strained substrate using a special adhesive. When the substrate undergoes stress changes, the resistance strain gauges also deform, causing a change in the resistance value of the strain gauges and a change in the voltage applied to the resistance.