Differencial pressure transmitter is vital instruments in many industrial processes, enabling precision measurement of pressure differences within a system. These types of transmitters are commonly used in applications where precise and accurate measurements of fluid, gas, or steam pressure are required, making them essential instruments for various industries such as oil and gas, chemical, and manufacturing.
Jiangsu Hongguang Instrument Factory Co, Ltd. was established in 1972, mainly produce industrial automation instrument, control valve and power cable. Industrial automation instrument contain pengukur aliran, pressure gauge, pressure transmitter, level transmitter, temperature gauge, temperature transmitter, digital display instrument.With more than two decades of experience, the company has gained a reputation for its reliable and accurate instrumentation products, making it a trusted brand in the industry.
What is differencial pressure transmitter?
Differencial pressure transmitter, also known as DP transmitters, are used to measure the difference between two pressures. They consist of two pressure chambers, each connected to a pressure port, and a sensing element in between. The sensing element can be a mechanical diaphragm, piezoresistive, or capacitive sensor, depending on the type of DP transmitter. As pressure is applied to the two ports, the sensing element measures the difference in pressure and outputs a signal that is proportional to the differential pressure.
The configuration of a differencial pressure transmitter is crucial to its performance and accuracy. The following are the basic components and configurations of a DP transmitter:
Basic components:
Pressure ports
These are the two openings on the transmitter where the pipes from the process connect. The high-pressure port, also known as the process pressure port, is connected to the point in the process where the pressure being measured is higher. The low-pressure port, also known as the reference pressure port, is connected to the point in the process where the pressure is lower.
Isolating diaphragms
These are thin metal barriers that separate the two pressure chambers to prevent the process fluid from coming into contact with the sensing element. They are designed to withstand high pressures and are usually made of materials such as stainless steel or titanium.
Sensing element
This is the heart of the differential pressure transmitter and is responsible for converting the mechanical pressure into an electrical signal. As mentioned earlier, there are different types of sensing elements, each with its advantages and limitations.
Rumah pemancar
This is the outer casing of the transmitter that protects the internal components and electronics. It is usually made of stainless steel, aluminum, or plastic, depending on the application.
Electronics
The electronics of a DP transmitter convert the electrical signal from the sensing element into a standard output signal, usually 4-20mA or digital signals such as HART, Foundation Fieldbus, or Profibus.
Configure
To configure a differencial pressure transmitter, several parameters must be set, depending on the specific process and application. These parameters include range, damping, output type, and calibration.
Jangkauan:The range refers to the minimum and maximum pressures that the transmitter can accurately measure. It is crucial to select the appropriate range, considering the expected operating pressure of the process to ensure accurate measurements.
Damping: Damping is the rate at which the signal output of the transmitter changes in response to a change in the measured pressure. It is necessary to apply damping in some applications to filter out any noise or fluctuation in the process to obtain stable and accurate readings.
Output type:The output type is the signal format of the transmitter, which can be analog or digital. Analog signals are the most commonly used, and they provide continuous and proportional measurements, while digital signals are more advanced and offer additional features, such as remote access and diagnostics.
Calibration: The calibration of a differential pressure transmitter is the process of adjusting the output signal to match the actual pressure readings in the process. Calibration is crucial to ensure the accuracy and reliability of the transmitter, and it must be done regularly to maintain its performance.
In addition to the basic components and configurations, some advanced features are available in modern differential pressure transmitters. These include digital displays, multiple output signals, and self-diagnostic capabilities. Digital displays allow operators to monitor the pressure readings directly on the transmitter, while multiple output signals enable communication with various control systems. Self-diagnostic features, such as automatic zero points adjustment, ensure the transmitter is functioning correctly and alert users to any issues or failures.
How does it work?
Working Process
The sensing element of a differencial pressure transmitter can be a mechanical or an electronic device. In a mechanical system, the movement of the diaphragm is transmitted through a linkage system to a pointer or a meter. An electronic system, on the other hand, uses a strain gauge or a pressure transducer to convert the movement of the diaphragm into an electrical signal.
The electrical signal is then amplified, linearized, and converted into a standard output, such as 4-20 mA, 0-5 VDC, or 0-10 VDC, which can be easily interfaced with a control system or a data acquisition system.
The output signal is directly proportional to the difference in pressure between the two inputs and can be used to calculate the flow rate, level, density, or any other process variable, depending on the application.
Aplikasi
Differential pressure transmitters have a wide range of applications in various industries. Some of the common uses include:
Ⅰ. Flow Measurement: They are widely used in flow measurement systems, such as in pipes, ducts, and open channels. By measuring the difference in pressure across a restriction or an obstruction, the flow rate can be accurately determined using Bernoulli’s equation.
Ⅱ. Level Measurement: They are also used in level measurement applications, such as in tanks, vessels, and wells. By measuring the pressure at the bottom and top of a liquid column, the level of the fluid can be calculated.
Ⅲ. Pressure Control: They are used in pressure control systems to maintain a constant pressure in a process. By comparing the desired pressure setpoint with the measured pressure, the transmitter can send a control signal to a control valve to adjust the flow rate and maintain the desired pressure.
Ⅳ. Filter Monitoring: In filtration systems, differential pressure transmitters are used to monitor the pressure drop across filters. As the filter gets clogged, the pressure drop increases, indicating the need for maintenance or replacement.
Ⅴ. HVAC Systems: In heating, ventilation, and air conditioning (HVAC) systems, differential pressure transmitters are used to control the airflow in ducts and maintain the desired pressure differentials between different zones.
Differencial pressure transmitters are essential for accurate pressure measurements in various industrial processes. The Hongguang Instrument Factory is a trusted manufacturer of high-quality DP transmitters, offering a wide range of products suitable for different applications. Understanding the basics and configuration of these transmitters is crucial for their proper functioning and maintenance, ensuring efficient and reliable measurement of pressure differences in processes.