A brief introduction to the structure and principle of 3151 differential pressure liquid level transmitter
Based on the northwest automation industrial control production, Xi'an Huaheng instrument manufacturer, with its own core, circuit board design and manufacturing technology, capacitive pressure sensor design and production technology, can extend and deform the core technology according to the customer's requirements at low cost, and realize personalized product customization. The main products are smart (SMART) series pressure transmitter, multi parameter transmitter, flowmeter, temperature sensor and level (liquid level transmitter manufacturer, which provides high performance price ratio industrial automatic transmitter manufacturer products for China's power, petroleum, chemical, metallurgical, cement, mining and other industries
差压液位变送器用于可以通过hart475手操器或HART 275手操器相互通讯，通过它们进行设定和监控等。差压液位变送器用于防止管道中的介质直接进入变送器里，感压膜片与变送器之间靠注满流体的毛细管连接起来。它用于测量液体、气体或蒸汽的液位、流量和压力，然后将其转变成4～20mA DC信号输出。3151差压液位变送器的结构原理及工作性能
The differential pressure liquid level transmitter is used to communicate with each other through Hart 475 or Hart 275, and to set and monitor through them. The differential pressure liquid level transmitter is used to prevent the medium in the pipeline from entering the transmitter directly. The pressure sensing diaphragm and the transmitter are connected by a capillary filled with fluid. It is used to measure the liquid level, flow and pressure of liquid, gas or steam, and then convert it into 4-20mA DC signal output. Structure principle and performance of 3151 differential pressure liquid level transmitter
1) The structure and principle of 3151 differential pressure liquid level transmitter. E-ja110a differential pressure liquid level transmitter transforms the differential pressure and pressure signals into frequency signals by two H-shaped vibration beams on the single crystal silicon resonant sensor and sends them to the pulse counter, and then directly transmits the difference between the two frequencies to the microprocessor for data processing. After the D / a converter, it is converted into 4-20mA output signal corresponding to the input signal, and a brain / Hart is superposed on the analog signal Digital signal for communication . The built-in characteristic correction memory in the capsule module mainly stores the correction data such as the ambient temperature, static pressure and input / output characteristics of the sensor. Through microprocessor operation, the transmitter can obtain excellent temperature, static pressure and output characteristics.
Through I-O port and external equipment (such as BT200 or 275 handheld intelligent terminal and I / O card with communication function in DCS), data is transmitted in digital communication mode, i.e. high frequency 2.4khz (brain protocol) or 1.2kHz (HART Protocol) digital signals are superimposed on 4-20mA signal line. During the communication, the frequency signal does not produce any disturbance to the 4-20mA signal, and the working principle of the frequency converter is shown in Figure 1.
2) The performance of 3151 differential pressure liquid level transmitter mainly includes: single crystal silicon resonant sensor; process connection is compatible with other products to achieve * good measurement; ultra-low power consumption, single static 0.096w, full range power consumption 0.48w, output current internal limit power consumption 0.6W; high stability and reliability; perfect self diagnosis and remote setting communication function; external zero / range adjustment 。
Self diagnosis troubleshooting of 3151 differential pressure liquid level transmitter
3151 differential pressure liquid level transmitter with microcomputer technology has very complete self diagnosis function. If an error is found during self diagnosis, the embedded indicator in the instrument head will display the error code, and then find out the fault condition according to the displayed error code. If the measured value is abnormal, it is necessary to determine whether the measured fluid is abnormal or the measurement system is wrong. If it is confirmed that the measurement system is in error, it is necessary to check the operation condition, installation environment and transmitter itself, and take corresponding measures to solve the problem.
1) When the output display of 3151 differential pressure liquid level transmitter exceeds the specified parameter value, first check whether there is error code display on the indicator hidden in the instrument head. If there is no error code display and the power wiring is correct, check whether the balance valve is fully closed and the high / low pressure valve is fully open, and whether there is leakage at the pressure measuring part of the impulse pipe and whether the high / low pressure pipe is connected correctly. If there is no problem with the above content, * and then zero, the fault can be solved [2-3].
2) When there is no output signal of 3151 differential pressure level transmitter or the output value does not match the actual flow or the output signal does not change due to the change of measured flow, first check whether there is error code display on the indicator hidden in the instrument head. If there is no self diagnosis error code prompt and the power supply wiring is correct, further check whether the power supply voltage is normal and the load resistance connection is correct. Check Whether there is pressure leakage in the impulse pipe of the pressure measuring part. If the cause still cannot be found, carefully check the transmitter circuit wiring to determine whether the fault is caused by disconnection or wiring error . The fault treatment of the instrument generally follows the principle from simple to complex. Because of its excellent performance, all kinds of faults in actual use are usually related to external factors such as the measured fluid, operation environment, etc. For example, if the zero position often changes or the indication value is not on time, it is likely that the air bubble is trapped in the pressure measuring part of the transmitter or impurities such as impure measured fluid are entrained. At this time, loosen the drain / gas screw, empty the trapped gas or impurities, and the fault can be solved.
Huaheng transmitter manufacturers have developed two core technologies, sensor and intelligent circuit board. Not only do they master all the core component technologies of all products, but also the accuracy of industrial automatic transmitter manufacturers is constantly improving, from level 0.2 to level 0.1. Through the extension of the core technology, other products for measuring flow and temperature can be deformed.
液位变送器选型 液位变送器生产原理 3151液位变送器选型