What is a SCADA system?

SCADA is a data acquisition and monitoring control system. The scada system is a computer-based production process control and scheduling automation system. It can monitor and control the operating equipment on site. Because each application field has different requirements for scada, the development of scada system in different application fields is not exactly the same.

The scada system is the most widely used in the power system, and the technology development is also the most mature. It is one of the most important subsystems of the energy management system (EMS system). It has the advantages of complete information, improved efficiency, correct control of system operation status, accelerated decision-making, and can help quickly diagnose system fault status. Now it has become an indispensable power dispatcher. Missing tools.

The scada system plays an irreplaceable role in improving the reliability, safety and economic benefits of power grid operation, realizing the automation and modernization of power dispatching, and improving the efficiency and level of dispatching.

How does SCADA work?

The SCADA system deploys multiple software and hardware elements, allowing industrial organizations to: monitor, collect and process data.

Connect and control machines and equipment such as valves, pumps, motors, etc. through HMI (Human Machine Interface) software.

Log the event to a log file.

In the basic SCADA architecture, sensor or manual input information is sent to PLC (Programmable Logic Controller) or RTU (Remote Terminal Unit), and then sent to a computer with SCADA software.

SCADA software analyzes and displays data to help operators and other workers reduce waste and improve the efficiency of the manufacturing process.

An effective SCADA system can greatly save time and money. Many case studies have been published, highlighting the benefits and savings of using modern SCADA software solutions such as ignition.

What is SCADA used for?

The SCADA system has a wide range of applications, and it can be used in the fields of data acquisition, monitoring and control and process control in electric power, metallurgy, petroleum, chemical, gas, railway and other industries. Its functions mainly focus on four aspects: real-time collection of production data, process monitoring of production equipment, abnormal alarms of production equipment, data analysis, data reports and dashboard display. Its characteristics mainly reflect the following aspects.

1. It supports more than 5000 communication protocols and meets the communication requirements of 99.99% of controllers and instruments on the market. Get through the automated hardware system and the information transmission of the information software system.
2. Isolate office network IP and industrial equipment IP in hardware to avoid IP conflicts.
3. Intuitive display of production dynamics, direct or indirect control of on-site equipment, to meet the needs of visual management.
4. Perform statistical analysis of data and display it through the dashboard.

The SCADA system is centered on the data collected in the production process. It is related to the distribution of people, machines, materials, methods, environments, testing, and R&D. It is based on the data generated during the operation of production equipment. It is also a big Most companies are most concerned about.

Secondly, the SCADA system is aimed at the application needs of the above-mentioned manufacturing enterprises. At the same time, it will give play to its own unique advantages to bring improvements and benefits to the enterprise.

1. Help companies collect all kinds of data in the production process in real time. Instead of manual operations, it also avoids certain losses caused by personnel errors. Not only improves work efficiency, but also enables real-time monitoring of production All abnormal data in the process provides another layer of guarantee for the quality of the product.
2. The SCADA system provides the production data of each device, which makes the production situation intuitive and clear, and facilitates the analysis of the production situation by the management personnel of the enterprise, and at the same time helps the enterprise optimize the production, making the production plan more scientific and reasonable.
3. Realize the digital and intelligent improvement of the management process of products, production schedule, production efficiency, quality information, equipment operation, etc., and optimize the digital management and control capabilities of the production process.
4. During the company’s external publicity and visit, the company’s image and professionalism will be improved by explaining the application and advantages of the system for the company.

Extended reading: PID Controller Working Principle

The difference between SCADA, DCS and PLC

SCADA and DCS are a concept, and PLC is a product, the three are not comparable:

1. PLC is a product, which can form SCADA, DCS;
2. DCS is developed from process control, and PLC is developed from relay-logic control system;
3. PLC is equipment, DCS and SCADA are systems.

In a narrow sense, DCS is mainly used for process automation. PLC is mainly used for factory automation (production line). SCADA is mainly used for wide-area needs. Such as oil fields, which stretch for thousands of miles of pipelines.

If they are unified from the perspective of computers and networks, the main reason for the differences lies in the application requirements. DCS often requires advanced control algorithms.

For example, in the oil refining industry, PLC requires high processing speed. Because it is often used in interlocking, even fail-safe systems. SCADA also has some special requirements. Such as vibration monitoring, flow calculation, peak and valley adjustment, and so on.

Therefore, you can simply think:

• SCADA is the dispatch management layer
• DCS is the plant management
• PLC is the field device layer

Sino-Inst offers over controllers for Industrial data recording and analysis.

It is widely used in hydropower, tap water, petroleum, chemical, machinery, hydraulic and other industries to measure, display and control the pressure of fluid media on site.

A wide variety of controllers are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of controllers, located in China.

What is meant by PID?

In the manufacturing process, if the equipment or space needs to be kept at a constant temperature, then PID is the best choice.
What is meant by PID?

P: Proportion, the input deviation is multiplied by a coefficient;
I: Integral, perform an integral operation on the input deviation;
D: It is differentiation, which performs a differential operation on the input deviation.

Mathematical description of PID:
u(t)=kp[e(t)+1/TI∫e(t)dt+TD×de(t)/dt].
Where
E(t) is the error signal;
U(t) is the output signal of the controller;
kp is the ratio coefficient;
TI is the integral time constant;
TD is the derivative time constant.

PID control is a kind of negative feedback control. Because in the feedback control system, the automatic regulator and the controlled object form a closed loop.

There are two possible situations when connected into a closed-loop: positive feedback and negative feedback.

The effect of positive feedback aggravates the imbalance of the inflow and outflow of the controlled object, resulting in system instability;

Negative feedback is to alleviate the imbalance, so as to correctly achieve the purpose of automatic control.

The instrument used in PID control is a PID regulator (also called a PID controller). Simply put, the PID control algorithm determines the price of the PID regulator. The temperature controller is also a kind of control algorithm that is more suitable for temperature control PID regulator. Its control algorithm is different from the regulator control algorithm commonly used for process control such as flow and pressure.

PID Controller Working Principle

PID controller, Promotion Integration Differentiation, that is, proportional-integral-derivative controller. It is mainly through the setting of three parameters Kp, Ki, and Kd. It is used to control the basic linearity and dynamic characteristics that do not change with time.

PID controller is based on the PID control principle to adjust the deviation of the entire control system. So that the actual value of the controlled variable is consistent with the predetermined value required by the process. Different control laws are applicable to different production processes. The corresponding control law must be selected reasonably. Otherwise, the PID controller will not achieve the expected control effect.

PID controller is a kind of feedback loop component that is very common in industrial control applications. This controller compares the collected data with a reference value. This difference is then used to calculate the new input value. The purpose of this new input value is to allow the system data to reach or maintain the reference value.

The PID controller can adjust the input value based on historical data and the occurrence rate of differences. This can make the system more accurate and more stable. It can be proved by mathematical methods. When other control methods lead to system stability errors or process repetitions, a PID feedback loop can keep the system stable.

Video source: https://www.youtube.com/watch?v=v27xYKdZUzI

PID Temperature Controller Working Principle

Proportional integral derivative (PID) controllers can be used as a means to control temperature, pressure, flow, and other process variables. As the name suggests, PID controllers combine proportional control with additional integral and derivative adjustments. Help the equipment to automatically compensate for changes in the system.

Computer-controlled thermostat: Using PID fuzzy control technology* Use advanced digital technology to form a fuzzy control to solve the problem of inertial temperature error through the combination of Pvar, Ivar, and Dvar (proportional, integral, derivative).

Many manufacturers often encounter the problem of inertial temperature error in the process of using the thermostat. Suffering cannot be solved, relying on manual pressure adjustment to control the temperature.

PID controller Applications

The PID controller is the most widely used controller. There are many digital pid algorithms.
PID controllers are mostly used for temperature control. But there are other more advanced and lower-level programs.

The PID regulator used by the instrument ranges from tens of yuan to tens of thousands of yuan. The difference lies in IO precision, type, algorithm complexity, operation speed, and additional functions.

The PID algorithm used by PLC is also different. Usually simpler than meters.

In the field of temperature control, there are PID meters, smart fuzzy meters, fuzzy PID meters, and even industrial computers.

If the temperature control also needs to control the temperature rise curve, then a simple PID meter is not suitable. A set value generator is also needed, and most intelligent thermostats with this function are built-in.

1. Classic PID control algorithm regulator

For example, the accuracy is 0.5%. The intelligent regulator is used for process control such as pressure, flow, and liquid level to achieve good control effects. The temperature control effect is not good when used for temperature control.

2. Fuzzy control algorithm regulator

Such as accuracy of 0.3%. The fuzzy PID regulator is used for pressure, flow, liquid level, and other process control effects. It is best for temperature control in plastic/food/packaging machinery, heating furnaces, and other industries with a constant temperature effect of ±1℃. PID parameter self-tuning effect is excellent It is the classic PID control algorithm regulator. The price of the two is the same.

3. Artificial intelligence control algorithm regulator

Such as an accuracy of 0.2%. This artificial intelligence regulator is suitable for all automatic control sites and can achieve very good control effects. The best constant temperature effect for temperature control is ±0.1℃. The effect of PID parameter self-tuning is better than the adjustment of classic PID control algorithms and fuzzy control algorithms The price is slightly higher. Product performance is no different from European and American products.

4. Temperature controller

Such as an accuracy of 0.2%. The temperature controller is dedicated to the temperature control of various large lag working conditions (such as kilns, electric furnaces). The temperature is constant and does not fluctuate. The performance is not much different from that of Japanese island power products. The cost is lower.

Related measurement and control instruments

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Sino-Inst offers over 10 PID controllers for Industrial data recording and analysis.

It is widely used in hydropower, tap water, petroleum, chemical, machinery, hydraulic and other industries to measure, display and control the pressure of fluid media on site.

A wide variety of PID controllers are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of PID controllers, located in China.

Types of pressure sensors

Pressure sensors can be classified according to the pressure range they measure, their operating temperature range or the type of pressure they measure. In terms of pressure type, pressure sensors can be divided into several major categories.

Absolute pressure sensors

Absolute pressure sensors measure pressure relative to an ideal vacuum pressure (0 PS or no pressure). With reference to vacuum, the atmospheric pressure at sea level is 101.325 kPa (14.7PSI).

Gauge Pressure Sensors

Gauge pressure sensors are used in different applications because they can be calibrated to measure pressure relative to a given atmospheric pressure at a given location. A tire pressure gauge is an example of a gauge pressure indication. More about: What is Diaphragm pressure gauge?

Vacuum Pressure Sensors

Vacuum pressure sensors are used to measure pressures that are less than atmospheric pressure at a given location.

Differential Pressure Sensor

A differential pressure sensor or transmitter measures the difference between two or more pressures introduced as inputs to a sensing unit. An example is the measurement of the pressure drop across an oil filter. Differential pressure is also used to measure the flow or level in a pressurized vessel.

Sealed Pressure Sensors

Extended reading: Featured Diaphragm Seal Pressure Transmitters

A sealed pressure transducer is similar to a gauge pressure transducer, except that it has been calibrated by the manufacturer to measure pressure relative to sea level pressure.

More about Industrial Pressure Sensors

Featured Pressure Sensors

Working Principles of Pressure Sensors

Pressure Sensors are devices that convert various pressures into another physical quantity (usually electricity) that can be easily processed and transmitted according to certain rules. pressure sensors generally consist of three parts: a sensitive element, a conversion element and a measurement circuit, sometimes with an additional auxiliary power supply.

Extended Reading: Digital Pressure Sensor-RS485

Let’s look at the technology used in pressure sensors in more detail.

Pressure measurement technologies

Extended reading: Pressure indicator transmitters

Pressure sensors, pressure transducers, and pressure transmitters

A pressure sensor is a device or device that can sense a pressure signal and convert the pressure signal into a usable output electrical signal according to a certain rule.
A pressure sensor usually consists of a pressure-sensitive element and a signal processing unit. According to different test pressure types, pressure sensors can be divided into gauge pressure sensors, differential pressure sensors and absolute pressure sensors. A pressure sensor is the core part of pressure transmitter.

In a pressure transducer, a thin-film or piezo-resistive pressure sensor is mounted on a process connection. The transducer converts pressure into an analog electronic output signal, typically as a millivolt per volt output. These signals are not linearized or temperature compensated.

A pressure transmitter has additional circuitry that linearizes, compensates, and amplifies the signal from a transducer. The different signal types are typically voltage signals (eg, 0 to 5 or 0 to 10 volts), milliamp (eg, 4 to 20 milliamp), or digital. The instrument can transmit the signal to a remote receiver.

Extended reading: Static pressure vs dynamic pressure vs total pressure

Pressure sensor performance parameters

Pressure sensors mainly have the following parameters.

1.Capacity.

The range refers to the rated load of the pressure sensor. The general unit is KGf, N, etc.. Such as the range of 100KGf, the sensor measurement range is 0-100KGf.

2. Rated output.

Sensitivity is the output signal coefficient of the pressure sensor, the unit is mV / V, common 1mV / V, 2mV / V, the full range of the pressure sensor output = working voltage * sensitivity, for example: working voltage 5VDC, sensitivity 2mV / V, the full range of output that is 5V * 2mV / V = 10mV, such as pressure sensors full range of 100KG, pressure full 100KG, the output that is 10mV, pressure 50KG that is 5mV.

3. Non-linearity.

Non-linearity is the percentage of the maximum deviation between the output value of the empty load and the output value of the rated load determined by the straight line and the actual measured curve of the increased load for the rated output value. In theory, the output of the sensor should be linear, but in fact it is not. Non-linearity is the percentage deviation from the ideal. Non-linear units: %FS, non-linear error = range * non-linearity, such as the range of 100KG, non-linearity of 0.05% FS, non-linear error that is: 100KG * 0.05% = 0.05KG.

4. Repeat ability.

Repeatability error refers to the repeated loading of the sensor to the rated load and unloading under the same environmental conditions. The maximum difference of the output value on the same load point during the loading process on the percentage of rated output.

5.Creep.

Creep refers to the load remains unchanged, other test conditions also remain unchanged, the pressure sensor output change over time on the percentage of rated output, generally taken 30min.

6.Hysteresis.

Hysteresis refers to the pressure sensor from no load gradually loaded to the rated load and then gradually unloaded. In the same load point on the maximum difference between the loaded and unloaded output on the rated output value of the percentage.

7. Zero balance.

Under the recommended voltage excitation, the output value of the pressure sensor at no load is a percentage of the rated output. Theoretically, the output of the pressure sensor at no load should be zero, in fact, the output of the pressure sensor at no load is not zero, which there is a deviation, zero output is the percentage of deviation.

8.Input resistance.

Input resistance is the signal output open circuit, the sensor is not pressurized, from the pressure sensor input (Cang positive pressure sensor for the red and black line) measured impedance value.

9.Output resistance.

Output resistance is a short circuit at the input of the pressure sensor, the sensor is not pressurized, the impedance measured from the signal output (Cangzhou pressure sensor for the green and white lines).

10.Insulation impedance.

Insulation impedance is the DC impedance value between the circuit of the pressure sensor and the elastomer.

11.Operation Temp range.

Operating temperature range refers to the pressure sensor in the temperature range of its performance parameters will not produce permanent harmful changes.

12. Compensated temp range.

Temperature compensation range refers to the temperature range, the rated output of the sensor and zero balance are closely compensated, so as not to exceed the specified range.

13. Temperature effect on zero.

Temperature effect on zero refers to the effect of changes in ambient temperature on the zero point of the pressure sensor. Generally used for every 10 ℃ change in temperature, the amount of change in zero balance caused by the percentage of the rated output to express, the unit: % F.S./10 ℃.

14. Temperature effect on out.

Sensitivity temperature drift is the change in the sensitivity of the pressure sensor caused by changes in ambient temperature. Generally expressed as a percentage of the rated output for each 10 ℃ change in temperature caused by the change in sensitivity, the unit is: F.S./10 ℃.

15. Safe Load Limit.

Safe overload means that the load will not cause destructive damage to the pressure sensor, but can not be overloaded for a long time.

16. Ultimate overload.

Ultimate overload is the limit value of the pressure sensor load.

17. Excitation voltage Excitation recommend.

Excitation voltage refers to the working voltage of the pressure sensor, generally 5-12VDC.

Extended Reading: Up to 800°C High Temperature Pressure Sensor

Applications of Pressure Sensors

Pressure sensor is one of the most commonly used sensors in industrial practice. It is widely used in various industrial self-control environments. It involves water conservancy and hydropower, railroad transportation, intelligent building, production automation, aerospace, military, petrochemical, oil well, electric power, ship, machine tool, pipeline and many other industries.

The following is a brief introduction to some application examples of pressure sensors.

1. Application to hydraulic system

Pressure sensor in the hydraulic system is mainly to complete the closed-loop control of the force. When the control valve spool moves suddenly, a spike pressure of several times the working pressure of the system will be formed in a very short period of time.

2. Pressure sensors in the application of water treatment

China’s environmental protection water treatment industry, in recent years, has been rapid development, and the future prospects are promising. Water and wastewater treatment processes rely on the use of pressure sensors to provide an important means of control and monitoring for system protection and quality assurance.

3. Application in injection molding

Pressure sensors have an important role in injection molds. Pressure sensors can be installed in the nozzles of injection molding machines, hot runner systems, cold runner systems and mold cavities to measure the plastic pressure somewhere between the nozzle of the injection molding machine and the mold cavity during the injection, filling, holding and cooling processes.

4. Applications in compressors, air conditioning and cooling equipment

Pressure sensors are commonly used in air compressors and air conditioning and refrigeration equipment. These sensors are compact and easy to install, and the pressure guide port is usually designed with a special valve needle.

5. Used in monitoring mine pressure

Sensor technology as one of the key technologies for mine pressure monitoring.

On the one hand, we should properly apply the existing variety of sensors to serve the mining industry;

On the other hand, sensor manufacturers develop and develop new pressure sensors to adapt to more mining industry applications.

Note that the pressure transmitter needs to be calibrated after a period of use. In order to ensure the accuracy of the quantity.

FAQ

Related Blogs

What is a pressure sensor? and other questions about pressure sensors. We hope that after reading this article, you will have a clear understanding.

Sino-Inst offers over 20 Pressure sensors. A wide variety of Pressure sensors options are available to you. Such as free samples, paid samples.

Sino-Inst is a globally recognized manufacturer of Pressure sensors, located in China. Sino-Inst sells through a mature distribution network that reaches all 30 countries worldwide. Pressure sensors products are most popular in Europe, Southeast Asia, and Mid East. You can ensure product safety by selecting from certified suppliers. With ISO9001, ISO14001 certification.

Static pressure vs dynamic pressure vs total pressure

According to the knowledge of fluid mechanics. The vertical force acting on the unit area of the fluid is called pressure. When the air flows along the inner wall of the duct, its pressure can be divided into static pressure, dynamic pressure and full pressure. The unit is mmHg or kg/㎡ or Pa, respectively.

Static pressure (Pi).

What is static pressure?

Static pressure is the pressure generated by the air molecules hitting the duct wall due to irregular movement.
When calculating, the static pressure with absolute vacuum as the calculation zero points are called absolute static pressure.
The static pressure with atmospheric pressure as the zero point is called relative static pressure.
The static pressure of air in air conditioning refers to the relative static pressure.
The static pressure is positive when it is higher than atmospheric pressure, and negative when it is lower than atmospheric pressure.

Dynamic pressure (Pb).

What is dynamic pressure?

Dynamic pressure refers to the pressure generated by the flow of air, as long as the air flow in the duct has a certain dynamic pressure, and is positive. Dynamic pressure = 0.5 * air density * wind speed 2 .

Total pressure (Pq).

What is total pressure?

The total pressure is the algebraic sum of the static and dynamic pressures: Pq=Pi+Pb .

The total pressure represents the total energy of 1m3 of gas. If the atmospheric pressure is the starting point of the calculation, it can be positive or negative.

Extended reading: Pressure indicator transmitters

Extended reading: Pressure Sensor Applications-Featured Industry Applications

The difference between static pressure, dynamic pressure and total pressure

Different nature

1. Total pressure: The pressure measured parallel to the wind flow, directly opposite to the direction of the wind flow.
2. Static pressure: the pressure on the surface of an object at rest or in uniform linear motion.
3. Dynamic pressure: When the object is moving in the fluid, the surface in the direction of the fluid movement. The fluid is completely blocked, where the fluid velocity is 0. Its kinetic energy is transformed into pressure energy, and the pressure increases.

Extended reading: wireless pressure transmitter

Features are different

1.Total pressure: air conditioning units or fresh air units are often installed at the end of the fan, the fan outlet wind speed is high, high dynamic pressure, static pressure is small. Engineering often installed at the exit of the anechoic static pressure box, reduce the dynamic pressure, increase the static pressure. At the same time, the same flow, muffling effect.

2.Static pressure: with no noise, no vibration, no impact.

3.Dynamic pressure: only the directional flow of air to show dynamic pressure. Dynamic pressure is directional, only the plane perpendicular or oblique to the direction of wind flow pressure. The plane of the vertical flow direction to bear the maximum dynamic pressure, the plane of the parallel flow direction to bear the dynamic pressure is zero. In the same flow section, because the wind speed at each point is not equal, the dynamic pressure varies. Dynamic pressure is not absolute pressure and relative pressure, always greater than zero.

Extended reading: extrusion melt pressure transducer

Different applications

• Total pressure: applied to air conditioning or fan products.
• Static pressure: applied to fluid dynamics.
• Dynamic pressure: applied to mines, aerospace, etc.

Extended Reading: Up to 800°C High Temperature Pressure Sensor

What is an example of static and dynamic pressure?

Example of static pressure: When water is stored in a closed container, the pressure generated by the water in the container is static pressure. For example, water stored in a water tower develops pressure due to its height.

Example of dynamic pressure: When water flows in a pipe, in addition to the static pressure due to the weight of the water, there is also pressure due to the flow speed of the water. This part of the pressure is dynamic pressure. For example, the pressure created when water from a faucet hits the bottom of a wash basin.

Dynamic Pressure Calculator

Dynamic pressure is the kinetic energy of a flowing fluid – liquid or gas – per unit volume – and can be expressed as

pd = 1/2 ρ v²

Where:
pd = dynamic pressure (N/m2 (Pa), lbf/ft2 (psf))
ρ = density of fluid (kg/m3, slugs/ft3)
v = velocity (m/s, ft/s)

Online Dynamic Pressure Calculator

What is a dynamic pressure sensor?

The piezoelectric effect is the main operating principle of dynamic pressure sensors. Dynamic pressure sensors cannot be used for static measurements.

This is because the charge after an external force is only saved when the circuit has an infinite input impedance.

This is not the case in practice, so this determines that dynamic pressure sensors can only measure dynamic stresses.

Extended Reading: Electronic Pressure Switch for Air Compressor

Featured Static Pressure & Dynamic Pressure Sensors

Extended reading: Measuring Flow With Pressure Sensors

Static pressure sensor and dynamic pressure sensor difference

1. Diaphragm pressure sensor is according to the structure of the sensor, according to the sensing principle diaphragm pressure sensor can be divided into different types such as piezoresistive, strain gauge, inductive, capacitive, piezoelectric, etc.
2. Among the above different principles of pressure sensors, piezoelectric pressure sensors are only suitable for measuring dynamic pressure. Therefore, dynamic calibration is required; other dynamic and static pressures can be measured. The most applications belong to the quasi-static measurement of very low frequency. Therefore, static calibration is the most used form of calibration. When the measured pressure band is wide, all kinds of pressure sensors should do frequency response calibration.

Extended reading: Silicon Pressure Sensor

Applications of dynamic pressure sensors

Dynamic pressure sensors are mainly used in the measurement of acceleration, pressure and force.

Dynamic pressure sensors are also widely used in biomedical measurements. For example, ventricular catheter microphones are made of piezoelectric sensors. Because dynamic pressure measurements are so common. This is why dynamic pressure sensors are so widely used.

Dynamic pressure transducers are used in a wide range of applications, typically to measure speed, pressure, and force. Therefore, they have a very high value in some products.

Extended reading: Best Price Ceramic Pressure Sensor

Related Blogs

Sino-Inst offers over 20 Pressure Transducers.

About 50% of these are 4-20ma Low-Pressure Transducers, 40% are Differential Pressure Gauge, and 20% are Diaphragm Seal Pressure transmitters, 20% are 4-20ma differential pressure transmitters.

A wide variety of  Pressure Transducers options are available to you, such as free samples, paid samples. 

Sino-Instrument is a globally recognized supplier and manufacturer of Pressure Transducers, located in China.

The top supplying country is China (Mainland), which supply 100% of Pressure Transducers respectively.

Sino-Inst sells through a mature distribution network that reaches all 50 states and 30 countries worldwide.

Pressure Transducers products are most popular in Domestic Market, Southeast Asia, and Mid East. 

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

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Piezoelectric pressure sensor working principle

Piezoelectric pressure sensors are mainly based on the piezoelectric effect (Piezoelectric effect). Use electrical components and other machinery to convert the pressure to be measured into electricity. Then perform measurement precision instruments such as pressure transmitters and pressure sensors.

Piezoelectric sensors can not be used in static measurement. The reason is the electric charge after the action of external force. When the circuit has infinite input resistance, it can be preserved.

But this is not the case.

Therefore, piezoelectric sensors can only be used in dynamic measurements.

Its main piezoelectric materials are: dihydrogen phosphate, sodium potassium tartrate and quartz. The piezoelectric effect is found on quartz.

When the stress changes, the electric field changes very little, and some other piezoelectric crystals will replace quartz.

Potassium sodium tartrate, it has a large piezoelectric coefficient and piezoelectric sensitivity. However, it can only be used indoors where the humidity and temperature are relatively low.

Dihydrogen phosphate is a kind of artificial crystal. It can be used in high humidity and high temperature environment. Therefore, its application is very wide.

With the development of technology, the piezoelectric effect has also been applied to polycrystals. For example: piezoelectric ceramics, niobate magnesium acid piezoelectric ceramics, niobate series piezoelectric ceramics and barium titanate piezoelectric ceramics, etc. are included.

The sensors based on the piezoelectric effect are electromechanical conversion and self-generation sensors. Its sensitive components are made of piezoelectric materials.

When the piezoelectric material is subjected to an external force, an electric charge will be formed on its surface. The electric charge will be amplified by the charge amplifier, the measuring circuit and the impedance converted. It will be converted into an electrical output proportional to the external force received.

It is used to measure force and non-electrical physical quantities that can be converted into force. For example: acceleration and pressure.

It has many advantages: lighter weight, reliable work, simple structure, high signal-to-noise ratio, high sensitivity and signal bandwidth, etc.

But it also has some shortcomings: some voltage materials are protected from moisture. Therefore, a series of moisture-proof measures need to be taken. And the output current response is relatively poor. Then it is necessary to use a charge amplifier or a high input impedance circuit to make up for this shortcoming. Make the instrument work better.

Extended reading: Silicon Pressure Sensor

Related Products:

Piezoelectric pressure sensor advantages and disadvantages

1. The advantages are bandwidth, high sensitivity, high signal-to-noise ratio, simple structure, reliable work, and lightweight.
2. The disadvantage is that some piezoelectric materials need moisture-proof measures. And the output DC response is poor. It is necessary to use a high input impedance circuit or a charge amplifier to overcome this defect.

Extended Reading: Digital Pressure Sensor-RS485

The working principle of 5 common pressure sensors

In addition to the Piezoelectric Pressure Sensors described in this article, there are many pressure transmitters and pressure sensors that can convert pressure into electrical signals.

So how do these pressure transmitters and pressure sensors convert pressure signals into electrical signals? What are the characteristics of different conversion methods?

Here, I have summarized the measurement principles of several common pressure sensors for everyone. hope that it can help us.

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Extended Reading: Up to 800°C High Temperature Pressure Sensor

Sino-Instrument is a globally recognized supplier and manufacturer of
Pressure Transducers, located in China.

The top supplying country is China (Mainland), which supply 100% of Pressure Transducers respectively.

Sino-Instrument sells through a mature distribution network that reaches all 50 states and 30 countries worldwide.

Pressure Transducers products are most popular in Domestic Market, Southeast Asia, and Mid East. 

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

Featured air pressure transducers

Extended reading: How to calibrate HART pressure transmitters

Air pressure transducer selection:

1. Measuring range (range)
2. The output signal, communication protocol, whether with display meter
3. Process interface (general, please provide thread specifications, flange type, provide specific flange standard, flange size, capillary length, process medium temperature, and other information)
4. Electrical interface
5. Installation method (horizontal installation or vertical installation)
6. Mounting bracket (flat bracket or L-shaped bracket, bracket material requirement: carbon steel or stainless steel)
7. Other requirements (explosion-proof, explosion-proof, lightning arrester, water, and oil prohibition treatment, etc.)

Read more about Gas Pressure Transducer-Sensor for Gas Pressure Measurement 

Tools for converting and calculating pressure values

Absolute pressure-Gauge pressure Converter	Pressure Unit Converter	Liquid Depth/Level to Hydrostatic Pressure Calculator
Differential Pressure Calculator	Pressure Transducer 4-20ma Output Calculator	Pressure to Liquid Level Calculator

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Sino-Inst offers over 20 air pressure transducers. A wide variety of air pressure transducer options are available to you. Such as free samples, paid samples. Sino-Instrument is a globally recognized manufacturer of air pressure transducers, located in China.

Sino-Inst sells through a mature distribution network that reaches all 30 countries worldwide. Air pressure transducer products are most popular in Europe, Southeast Asia, and Mid East. You can ensure product safety by selecting certified suppliers. With ISO9001, ISO14001 certification.

Steam pressure transmitter performance

Extended Reading: Smart pressure transmitter

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Extended reading: Featured Diaphragm Seal Pressure Transmitters

Steam pressure transmitter installation

1. When wiring, pass the cable through the waterproof connector (accessory) or flexible tube and tighten the sealing nut to prevent rainwater from leaking into the transmitter housing through the cable.
2. Prevent the pressure transmitter from contacting corrosive or overheated media;
3. When measuring the liquid pressure, the installation position of the transmitter should avoid the impact of the liquid (water hammer phenomenon) to avoid damage to the sensor overpressure;
4. When measuring the liquid pressure, the pressure port should be opened on the side of the processing pipeline to avoid precipitation and slag;
5. When measuring gas pressure, the pressure tap should be opened at the top of the process pipeline. The transmitter should also be installed on the upper part of the processing pipeline. So that the accumulated liquid can be easily injected into the processing pipeline;
6. Prevent dross from depositing in the duct;
7. When measuring steam or other high-temperature media, a buffer tube (coil) and other condensers should be connected. The working temperature of the pressure transmitter should not exceed the limit;
8. When freezing occurs in winter, the transmitter installed outdoors must take anti-freezing measures. Avoid volume expansion of the liquid in the pressure inlet due to icing, leading to damage to the sensor;
9. The pressure guiding tube should be installed in a place with small temperature fluctuations;

Read more about: What is a pressure sensor and how it works? 

What should be paid attention to when measuring the pressure on the steam pipeline?

Pressure transmitters are used for steam metering and pipeline monitoring.

The temperature in the steam pipeline is generally relatively high. The low is more than one hundred degrees Celsius, and the high is two to three hundred degrees Celsius.

The start and stop of the valve will also cause the pressure in the pipeline to fluctuate.

Today we are going to talk to you about what to pay attention to when measuring the pressure of steam pipes?

Extended Reading: Up to 800°C High Temperature Pressure Sensor

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Sino-Inst offers over 10 Steam Pressure Transmitters. A wide variety of  Steam Pressure Transmitter options are available to you. Such as free samples, paid samples.

Sino-Inst is a globally recognized manufacturer of Steam Pressure Transmitters, located in China. Sino-Inst sells through a mature distribution network that reaches all 30 countries worldwide. Steam Pressure Transmitter products are most popular in Europe, Southeast Asia, and Mid East. You can ensure product safety by selecting certified suppliers. With ISO9001, ISO14001 certification.