How to select the model of pressure transmitter - Knowledge - Xi'an Huaheng Instrument Co.,Ltd
How To Select The Model Of Pressure Transmitter
What is the selection method for capacitive pressure transmitters? It is very important for the user to choose a suitable and practical capacitive pressure transmitter, so that the problems in the future use will be relatively small, so what kind of selection method can be used for reference? Today, Xiaobian will introduce you to the selection method of capacitive pressure transmitter.
1. What kind of pressure should be measured by the transmitter: first determine the maximum value of the measured pressure in the system. Generally, the demand is to select a transmitter with a pressure range that is about 1.5 times larger than the maximum value. This is mainly in many systems, especially in water pressure measurement and processing, with peaks and irregular irregular ups and downs, which can damage the pressure sensor, continue high pressure values or slightly exceed the transmitter's Calibrating the maximum value will shorten the life of the sensor, but because of this, the accuracy will decrease. Therefore, a buffer can be used to lower the pressure glitch, but this will slow down the sensor's response speed. Therefore, when selecting a transmitter, it is necessary to fully consider the pressure scale, accuracy and stability.
2. What kind of pressure medium: What we should consider is the medium measured by the capacitive pressure transmitter. The viscous liquid and mud will block the pressure interface, and the solvent or corrosive substances will not be damaged. Touch the data directly with these media. These elements will determine whether a direct barrier film and direct touch with the media can be selected. The usual capacitive touch transmitter touch media is made of 318 stainless steel. If your medium is not corrosive to 318 stainless steel, then basically all capacitive pressure transmitters are suitable for your medium pressure measurement. If your medium is corrosive to 318 stainless steel, then we should use a chemical seal, which not only can measure the pressure of the medium, but also can be used to hinder the contact of the medium with the capacitive pressure transmitter. Then it is used to maintain the capacitive pressure transmitter, extending the life of the capacitive pressure transmitter.
3. How much accuracy the transmitter needs: resolution accuracy, nonlinearity, hysteresis, non-repetition of electromechanical business network, temperature, zero offset scale, temperature effect. But mainly by nonlinearity, hysteresis, non-repetition, the higher the accuracy, the higher the price. Every electronic measuring instrument will have accuracy errors, but the accuracy level of each country is different. For example, the accuracy of the national standard such as China and the United States is the best linearity of the sensor, that is, we usually The accuracy of the measured scale is between 12% and 92%; while the accuracy of the European standard is the least linearity, which is what we usually call 0 to 10% and 90% to 100% of the measurement. The precision between.
4, the temperature scale of the transmitter: usually a transmitter will calibrate two temperature scales, that is, the temperature scale of normal operation and the scale of temperature can be compensated. The normal operating temperature scale refers to the temperature scale of the transmitter when it is not damaged under the working condition. When the temperature is exceeded, the performance target of the application may not be achieved. The temperature compensation scale is a typical scale smaller than the operating temperature scale. Working on this scale, the transmitter will definitely reach its performance target. Temperature changes affect its output in two ways, one is zero drift; the other is affecting full-scale output.
5. What kind of output signal is required: mV, V, mA and frequency output digital output. What kind of output is selected depends on various factors, including the interval between the transmitter and the system controller or display, can there be "noise"? Or other electronic interference signals. Can you demand an expander, the orientation of the expander, etc. For many OEM devices with short inter-driver and controller spacing, the most economical and useful solution for transmitters with mA output is the most economical solution for expanding the output signal. For the long interval transmission or the presence of strong electronic interference signals, the best choice is mA output or frequency output. In the case of high RFI or EMI targets, in addition to the need to pick mA or frequency output, consider special maintenance or filters.
6. What kind of excitation voltage is selected: the type of output signal determines how the excitation voltage is selected. Many expansion transmitters have built-in voltage conditioning equipment, which results in a larger supply voltage. Some transmitters are quantitative equipment, which requires a stable operating voltage. Therefore, it is possible to determine whether a working voltage can be selected with a sensor with a conditioner. When selecting a transmitter, it is necessary to consider the operating voltage and system cost.
7. The transmitter needs to maintain stability after the timeout operation: Some transmitters will “drift” after passing the timeout operation. Therefore, it is necessary to know the stability of the transmitter before the acquisition. This kind of pre-operation can Reduce the cost of future use.
8, the package of the transmitter: the package of the transmitter, especially often simple negligence is its rack, but this point will gradually expose its defects in the future application. In the purchase of the transmitter, we must consider the future working environment of the transmitter, how to humidity, how to install the transmitter, whether there will be intense impact or oscillation.
The selection method of the capacitive pressure transmitter has been introduced. Now everyone knows about the selection of the capacitive pressure transmitter. The user's help is very great. When you choose the capacitive pressure transmitter later. Select the applicable capacitive pressure transmitter.
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