How to choose a pressure transmitter

How to select a pressure transmitter? The following points are for reference 1. What kind of pressure does the transmitter need to measure First, determine the maximum value of the measured pressure in the system. Generally, it is necessary to choose a transmitter with a pressure range that is about 1.5 times larger than the maximum value. This is mainly due to peak values and continuous irregular fluctuations in many systems, especially in water pressure measurement and processing, which can damage pressure sensors. Continuous high pressure values or slightly exceeding the maximum calibration value of the transmitter can shorten the lifespan of the sensor and also reduce accuracy. So a buffer can be used to reduce pressure spikes, but this will slow down the response speed of the sensor. So when choosing a transmitter, it is necessary to fully consider the pressure range, accuracy, and stability. 2. What kind of pressure medium Viscous liquids and mud may block the pressure interface, and solvents or corrosive substances may damage the materials in direct contact with these media in the transmitter. The above factors will determine whether to choose direct isolation membranes and materials that come into direct contact with the medium. 3. What precision is required for the transmitter The factors that determine accuracy include nonlinearity, hysteresis, non repeatability, temperature, zero offset scale, and the influence of temperature. But mainly due to nonlinearity, hysteresis, non repeatability, the higher the accuracy, the higher the price. 4. Temperature range of transmitter Usually, a transmitter will calibrate two temperature ranges, one of which is the normal operating temperature and the other is the temperature compensation range. The normal operating temperature range refers to the temperature range when the transmitter is not damaged in its working state. If it exceeds the temperature compensation range, it may not meet its performance indicators for application. The temperature compensation range is a typical range that is smaller than the operating temperature range. Working within this range, the transmitter will definitely achieve its expected performance indicators. Temperature changes affect its output from two aspects: zero drift and full-scale output. For example:+/- X%/℃ of full scale,+/- X%/℃ of reading,+/- X% of full scale when outside the temperature range, and+/- X% of reading within the temperature compensation range. Without these parameters, it will lead to uncertainty in use. Is the change in transmitter output caused by pressure changes or temperature changes. The temperature effect is the most complex part of understanding how to use a transmitter. 5. What kind of output signal is needed The choice of mV, V, mA, and frequency output for digital output depends on various factors, including the distance between the transmitter and the system controller or display, the presence of "noise" or other electronic interference signals, the need for an amplifier, and the position of the amplifier. For many OEM devices with short distances between transmitters and controllers, using mA output transmitters is the most economical and effective solution. If the output signal needs to be amplified, use a transmitter with built-in amplification. For long-distance transmission or strong electronic interference signals, mA level output or frequency output is used. If in an environment with high RFI or EMI indicators, in addition to choosing mA or frequency output, special protection or filters should also be considered. 6. What kind of excitation voltage to choose The type of output signal determines the choice of excitation voltage. Many transmitters have built-in voltage regulation devices, so their power supply voltage range is large. Some transmitters are quantitatively configured and require a stable operating voltage. Therefore, the operating voltage determines whether to use a sensor with a regulator. When selecting a transmitter, the operating voltage and system cost should be considered comprehensively. 7. Do you need a transmitter with interchangeability Determine whether the required transmitter can adapt to multiple usage systems. Generally speaking, this is very important, especially for OEM products. Once the product is delivered to the customer, the cost for calibration is quite high. If the product has good interchangeability, even changing the transmitter used will not affect the overall performance of the system. 8. The transmitter needs to maintain stability after timeout operation Most transmitters will experience "drift" after excessive operation, so it is necessary to understand the stability of the transmitter before purchasing. This pre operation can reduce various troubles that may occur in future use. 9. Encapsulation of transmitter The packaging of the transmitter is often overlooked as its rack, but this will gradually expose its shortcomings in future use. When choosing a transmitter, it is important to consider the future working environment, humidity, installation methods, and whether there will be strong impacts or vibrations.

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