经过多年的生产和使用实践，其性能及质量可靠性均己达到国内领先水平。 After many years of production and use of pressure transmitters , its performance and quality reliability have reached domestic leading levels. It is widely used in the measurement of process parameters such as differential pressure, pressure, liquid level, and flow in petroleum, chemical, metallurgy, electric power, papermaking, medicine, and textile industries. HY series pressure / differential pressure transmitters are designed to meet the requirements of domestic users. The intelligent series can be adjusted to zero or re-calibrated on-site by using local buttons. Passive calibration and data configuration can also be achieved through a handheld programmer or communication software. AW110 series 3351 capacitive transmitters are developed on the basis of advanced foreign manufacturing technology and equipment, drawing on the advanced technology of similar domestic products. The electronic components and key parts of the transmitter are selected from international high-quality products. The modular design of the product and the full-chip package make the product more compact and perfect. Guaranteed excellent machine performance. 1 The metal-sealed delta chamber is used as the sensing element, which eliminates the problems of poor resistance to shock and vibration of the mechanical transmitter. It also resolves errors caused by external stress or torque. 2 The delta chamber of the transmitter is specially designed to make the volume change of the working chamber less than 0.16cm3. It can prevent additional errors caused by excessive changes in the temperature or pressure of the measured medium. 3 The whole machine has no mechanical moving parts, reducing the failure rate. 4 built-in digital display head and setting buttons, easy to adjust the zero or span setting. The output signal conforms to the HART bus protocol and can be interconnected with other HART protocol devices. There are two buttons in the table, which can adjust the zero point, full scale and restore the original data of the meter when it leaves the factory.
Working principle of pressure transmitter: Two kinds of pressure of the measured medium enter the two high and low pressure chambers, and act on the two isolation diaphragms of the delta element (that is, the sensitive element), through the isolation diaphragm and the filling liquid in the delta element Transfer to both sides of the pre-tensioned measuring diaphragm. The measuring diaphragm and the electrodes on both sides of the insulator constitute a capacitor. When no pressure is applied or the pressure on both sides is equal, the measuring diaphragm is in the middle position, and the capacitors on both sides have the same capacitance. When the pressure on the two sides is inconsistent, the measurement diaphragm is displaced. The displacement is proportional to the pressure difference, so the capacitance on both sides is not the same. By detecting the differential capacitor on the capacitor plate, the difference is determined by the electronic circuit. The moving capacitor is converted into a two-wire current signal of 4-20mADC. The working principle of pressure transmitter and absolute pressure transmitter is the same as that of differential pressure transmitter, except that the pressure in the low pressure chamber is atmospheric pressure or vacuum.
主要技术参数： Main technical parameters of pressure transmitter :
Basic accuracy: ± 0.1% calibration range stability: 6 months, ± 0.1% URL
Influence of ambient temperature: zero point error ± 0.2% URL / 56 ℃
Overall error ± (0.2% URL + 0.18% calibration range) / 56 ° C
Impact of installation position: Max. 0.25KPa, which can be cleared by setting, no effect on range. Working voltage: 24 DC
Output signal: 4-20mA DC
Load capacity: 100 ～ 500 ohms Working temperature: -30 ～ ＋ 85
Display: LCD digital display explosion-proof: intrinsically safe ibⅡCT5
Protection performance: IP65
Overall dimensions: length × width × height 110 × 125 × 200mm
HY series of intelligent (HART protocol) transmitters are tested high and low temperature environment one by one before leaving the factory to ensure the test accuracy within the range of the industrial temperature. It has the characteristics of high accuracy, strong stability and good repeatability. The measured value is displayed digitally. There are two keys in the meter, which can adjust the zero point, full scale and restore the original data of the meter.
电路板如何进行检查：1． How to check the pressure transmitter circuit board: Turn on the power and check the status of the voltage signal at the output of the transmitter after the input pressure signal is given. If there is no output voltage, first check whether the power supply voltage is normal; whether it meets the power supply requirements; whether there is a wiring error between the power supply and the transmitter and the load equipment. If no voltage or reverse polarity is connected to the transmitter terminals, the transmitter will have no voltage signal output. Excluding the above reasons, you should further check the components of the amplifier board for damage; if there is a poor contact of the connector of the circuit board, you can compare the measured voltage of the normal instrument with the measured voltage of the faulty instrument to determine the fault. Point, if necessary, replace the faulty amplifier board. When checking the flow transmitter, pay special attention to anti-static measures for the J-type amplifier board. 2. After turning on the power, after the input pressure signal is given, if the transmitter output is too high (greater than 10VDC), or the output is too low (less than 2.0VDC), and the input pressure signal is changed and the zero and range screws are adjusted, the output does not respond. . For this kind of failure, in addition to checking whether there is any abnormality in the sensitive part of the transmitter measurement part, you should check whether the "oscillation control circuit part" on the transmitter amplifier board is working normally. The normal peak voltage between high frequency transformer T1-12 should be 25 ~ 35VP-P; the frequency is about 32kHz. Secondly, check the working conditions of the operational amplifiers on the amplifier board; whether the components of each part are damaged. This type of failure requires the amplifier board to be replaced. 3． The transmitter is very strict in the design of the circuit and the quality of the process assembly. In actual use, for the line failure that occurs, it is best to contact the manufacturer to replace the faulty circuit board after inspection and confirmation to ensure the long-term stability of the instrument. And reliability.