Surely the word Pressure is not too strange for us in today’s life. They are associated with and give many uses to human life. In industrial production, it is indispensable for measuring devices, pressure gauges & pressure sensors. Here, plctop.com and you learn about the concept, calculation formula and classification of pressure sensors.
1. What is Pressure?
Pressure is a physical quantity known to us during our schooling. Pressure is the magnitude of the pressure exerted over a given area. Meanwhile, pressure is the force perpendicular to the pressed surface. In simple terms, pressure is generated when a selector acts perpendicular to the surface. Usually pressure is measured with a ratio starting with 1kPa = 1000Pa.
Equation for Pressure
In there:
+ P – Pressure
+ F is the pressure applied to the pressed face with contact area S.
Table of pressure measurement units
Pressure gauge is one of the most commonly used measuring devices today. However, depending on the production area of different equipment, there are different units. This makes it difficult for some users. For the convenience of pressure measurement and pressure reading. We will standardize on a unit that is bar.
2. What is Pressure Sensor?
Pressure sensor is a type of sensor used to measure pressure, pressure in tanks or pipelines for gas, steam, or liquid. Their job is to monitor pressure or pressure. And transfer that information to the display or controller as a 4-20mA signal.
There is also a type designed to measure in dynamic mode to record very high rate changes of pressure. Example applications for this type of sensor are the measurement of combustion pressure in engine cylinders or in gas turbines & internal combustion engines. These sensors are typically manufactured from piezoelectric materials such as quartz.
3. Types of Pressure Sensors
How to classify pressure sensor? There are many ways to classify pressure sensors, which can be classified according to the pressure range they measure, the operating temperature range & most importantly the type of pressure they measure. They include 3 types of relative pressure sensor, absolute pressure sensor & differential pressure sensor. Let’s learn more about each type of feeling!
Gauge Pressure Sensor
Relative pressure sensor is based on the principle of comparison with air pressure. When the pressure sensor is placed in the atmospheric environment, the equivalent pressure being measured is 0 bar.
Some standard temperature and pressure conditions | Standard values of barometric pressure such as 101,325 kPa or 100 kPa have been defined, and some instruments use one of the standard values as a discontinuous reference instead of the actual pressure varying continuously. surrounding gas. This undermines the accuracy of these tools, especially when used at high altitude
For example, when the relative pressure is equal to 1 bar, the equivalent pressure at the measuring site is 1 bar greater than atmospheric pressure.
Absolute Pressure Sensor
The absolute pressure sensor is operated on the principle that the sensor is compressed 1 bar into the sensor. When the sensor is placed in an atmospheric environment, the equivalent pressure being measured is 1 bar.
The use of absolute pressure sensors is very limited in certain circumstances. Usually in areas with large vacuum or frequently operating in vacuum mode.
For example, when placed in the air and there is a force acting with a quantity of 1 bar, the measured value of the absolute pressure sensor is 2 bar.
Differential Pressure Sensor
This sensor measures the difference between two pressures, one is connected to each side of the sensor, the differential pressure sensor is used to measure many characteristics, such as pressure drop on the oil filter or air filter, liquid level (by comparing pressure above and below liquid) or flow rate (by measuring pressure change over a limit), This pressure difference measurement is made displayed using a differential pressure gauge or differential pressure sensor.
Usually, the locations where the differential pressure is to be measured usually has a fairly small measuring range, ranging from 0-100Pa (pascal).
4. Pressure sensor selection parameters
+ Purpose of using pressure sensor
+ Detailed specifications of the sensor to be used
+ Output signal of pressure sensor (normally 4-20mA)
+ Working environment of pressure sensor
+ Permissible error of the pressure sensor to be measured
+ Response time
+ Can the parameters on the sensor be adjusted?
+ Connection type of sensor
+ Power supply
5. Application of pressure sensor
+ Pressure sensors have many industrial applications. These can be mentioned as: Measuring water pressure, Measuring compressed air pressure, Used to measure hydraulic pressure, Used to measure gas pressure & Measure pressure of other liquids…
+ Pressure sensor used to measure in the boiler system, usually measured directly on the boiler. This area needs quite high precision measurement & is subject to high temperatures.
+ The gas generators also need to measure the pressure to limit the output pressure, avoiding the case of overpressure leading to damage & explosion.
+ To pressurize or control the pressure after the control valve, the pressure sensor plays a very important role because it will directly affect the output pressure after the control valve.
+ On crane trucks, there are often hydraulic berths, the requirement to monitor these hydraulic berths is very important because it will affect the traction force of the dump truck. So they always install pressure sensors to monitor the pressure on these hydraulic cylinders.
+ Tanks containing water or materials often use pressure sensors to measure the level of these tanks
So plctop.com has learned with you an overview of all types of pressure sensors, if you have any questions, please comment below the article. Thank you for reading.
