Selection rules for pressure transmitters

1. According to the type of pressure to be measured
The main types of pressure include gauge pressure, absolute pressure, differential pressure, etc. Gauge pressure refers to the pressure based on the atmosphere, which is less than or greater than atmospheric pressure; Absolute pressure refers to using the zero position of absolute pressure as a benchmark, higher than absolute pressure; Differential pressure refers to the difference between two pressures.
2. According to the measured pressure range
In general, 80% of the measurement range is selected based on the actual measured pressure.
Consider the maximum pressure of the system. Generally speaking, the maximum pressure range of a pressure transmitter should reach 1.5 times the maximum pressure value of the system. Some water pressure and process controls may have pressure spikes or continuous pulses. These spikes may reach 5 or even 10 times the "maximum" pressure, which may cause damage to the transmitter. Continuous high-voltage pulses, approaching or exceeding the maximum rated pressure of the transmitter, will shorten the practical life of the transmitter. But increasing the rated pressure of the transmitter will sacrifice its resolution. Buffers can be used in the system to reduce spikes, which can slow down the response speed of the sensor.
Pressure transmitters are generally designed to withstand maximum pressure for 200 million cycles without compromising performance. When selecting a transmitter, a compromise solution can be found between system performance and transmitter lifespan.
3. According to the tested medium
According to the different measurement media, it can be divided into dry gas, gas liquid, highly corrosive liquid, viscous liquid, high-temperature gas liquid, etc. Proper selection based on different media is beneficial for extending the service life of the transmitter.
4. Based on the maximum overload of the system
The maximum overload of the system should be less than the overload protection limit of the transmitter, otherwise it will affect the service life of the transmitter and even damage it. The safety overload pressure of a pressure transmitter is usually twice the full range.
5. According to the required accuracy level
The measurement error of the transmitter is divided by accuracy level, and different accuracies correspond to different basic error limits (expressed as a percentage of full scale output). In practical applications, selection is based on the control requirements of measurement errors and the principle of economic use.
6. According to the operating temperature range of the system
The temperature of the measuring medium should be within the working temperature range of the transmitter. If used over temperature, it will cause significant measurement errors and affect the service life of the transmitter; In the production process of pressure transmitters, temperature effects are measured and compensated to ensure that the measurement errors caused by temperature effects are within the accuracy level requirements. In situations with high temperatures, it is possible to consider choosing a high-temperature pressure transmitter or adopting auxiliary cooling measures such as installing condenser pipes and radiators.