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What is a pressure transmitter?

What is a pressure transmitter?

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What is a pressure transmitter?

What is a pressure transmitter? A pressure transmitter or pressure sensor is a device that measures pressure in a liquid, fluid, or gas, or level of industrial liquids and gases.

Transmitter use to measure pressure in different processes.

Pressure transmitters are divided into three types:

Absolute Transmitter:

Absolute transmitter takes vacuum pressure as its base and then measures process pressure.

Gauge Transmitter:

This type measures process pressure with the location’s atmospheric pressure as a base.

Differential Transmitter:

When sensing units are introduced to multiple pressures as inputs, differential transmitters measure the differences between the various pressures.

Then it’s transducing that pressure into an analog electrical signal.

There are various types of pressure transducers, such as:

  • Pneumatic transmitter
  • Analog transmitter
  • Digital transmitter

Transducer

A transducer is a device which measures a physical quantity such as temperature or pressure and converts it into an electrical output signal.

What is the difference between transmitter and transducer

Both transducers and transmitters convert energy from one form to another and give an output signal. The signal is directed to any device that interprets it and uses it to display a record or alter the pressure in a system.

So how do you decide whether it is best to use a transducer or transmitter for your application? Transducers and transmitters are virtually the same things, the main difference being the kind of electrical signal each sends.

A transducer sends a signal in volts (V) or millivolt (mV) and a transmitter sends a signal in milliamps (mA).

If the electrical connections in your process are short, such as in the laboratory or inside an electronics enclosure, a pressure transducer is more desirable as they tend to be smaller and there are very few active electronic components that can be upset by electromagnetic interference.

HART®

HART or Highway Addressable Remote Transducer is a type of digital communications protocol for configuring and reading instrumentation via the 4 to 20mA current loop. HART® data is communicated via a low-level AC digital signal which is superimposed on a 2 wire 4-20mA current loop signal and functions simultaneously without interfering with the measurement output signal.

Types of pressure

Types of pressure

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Types of pressure

Pressure is an expression of force exerted on a surface per unit area. In this article, you found Types of pressure.

Gauge Pressure

The most common measurement of pressure is gauge pressure which is the pressure difference between the measured pressure and ambient pressure.

The term pressure is used if the measured pressure is higher than the atmospheric pressure. The term vacuum is used if the measured pressure is below atmospheric pressure.

The use of either of these terms automatically implies that the pressure (or vacuum) being measured is with respect to ambient pressure

(i.e. gauge pressure or vacuum).

In order to distinguish absolute pressure measurements, the words “absolute pressure” must be used.

Gauge Pressure uses a reference to the atmosphere around the sensor. Because the sensing element has a deflection due to a pressure change, a reference point is needed to know exactly what pressure is being measured.

Pressure sensors that use gauge pressure—typically seen in PSIG, BARG, and kPaG —have some type of vent.

This vent can be built into the sensor or even through a tube in the electrical connection. The vent is positioned to use atmospheric pressure as a reference point for the sensor to measure the media.

One common reason for using gauge pressure is to ensure that with any location throughout the world, the sensor will always reference the location in which it is installed.

Absolute Pressure

The most definite reference point is absolute zero pressure.

This is the pressure of empty space in the universe. When pressure is based on this reference point, it is called absolute pressure.

To distinguish it from other types of pressures it is accompanied by the suffix “a” or “abs” (from the Latin: absolutus = independent, separate from).

Absolute Pressure a perfect vacuum as its reference. This type of pressure reference is the gauge pressure of the media plus the pressure of the atmosphere.

As locations change, especially when dealing with elevation changes, the reference point can change because of atmospheric pressure differences.

Using an absolute pressure sensor eliminates the reference to a varying atmospheric pressure and relying on a specific pressure range for reference.

Differential pressure

Differential Pressure can be a little more complex than gauge or absolute but is simply measuring the difference between two media.

Although most gauge pressures are technically a differential pressure sensor—measuring the difference between the media and atmospheric pressure—a true differential pressure sensor is used to identify the difference between the two separate physical areas.

For example, the differential pressure is used to check the pressure drop—or loss—from one side of an object to the other.

The difference between the two pressures P1 and P2 is referred to as the pressure differential                ΔP = P1 – P2.

The difference between two independent pressures is called the differential pressure

Atmospheric pressure

The most important pressure for life on earth is atmospheric air pressure pamb (amb = ambient, surrounding).

It is produced by the weight of the atmosphere surrounding the earth up to an altitude of about 300 miles.

Atmospheric pressure decreases continuously up to this altitude until it practically equals zero (full vacuum).

Atmospheric air pressure undergoes climatic changes, as shown by the daily weather report.

At sea level, pamb has an average value of 29.90 inches of Mercury (“Hg). In high or low-pressure weather zones it can fluctuate by as much as ± 5%.

 Five main units of pressure

The unit of pressure in the SI system is the pascal (Pa), defined as a force of oneNewton per square meter. The conversion between atm, Pa, and torr is as follows: 1 atm = 101325 Pa = 760 torr.

 

Here you can find many kinds of pressure gauges that use in the industry, for example, oil & refinery & food beverage and many more factories.

We can supply and deliver the products from any points to UAE or export the products for any points that you want.

Saba Dejlah is the supplier for any Valves, Gauges, Compressors, Transmitters, Thermometers,…

 

Pressure

What is Pressure?

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What is Pressure?

What is pressure ? pressure is defined as force per unit area.

At first, we explain the concept of Pressure in Science, Physics, and Chemistry.

Pressure, in the physical sciences, the perpendicular force per unit area, or the stress at a point within a confined fluid. … In SI units, the pressure is measured in pascals; one pascal equals one newton per square meter. Atmospheric pressure is close to 100,000 pascals.

PRESSURE is a force exerted by the substance per unit area on another substance. The pressure of a gas is the force that the gas exerts on the walls of its container.

In other words, The rapid motion and collisions of molecules with the walls of the container causes pressure (force on a unit area). Pressure is proportional to the number of molecular collisions and the force of the collisions in a particular area.
The more collisions of gas molecules with the walls, the higher the pressure.

pressure

 

So to create a large amount of pressure, you can either exert a large force or exert a force over a small area (or do both).

This force can be exerted by liquids, by gases or vapors, or by solid bodies.
Surface compression takes place at the interface between two solid bodies, but for our purposes, we can consider this additional force negligible.

Common Units of Pressure

There are three general classifications for units of  measurement as follows:

Customary (inch, pound force, second, ampere)- used primarily in English speaking countries, but in many countries are being replaced by SI units. Customary units of pressure include PSI, in. Hg, in.H2O.

 

SI – (meter, Newton, second, ampere) – Commonly used in Europe and now popularly known as “metric” units. SI units of pressure include bar, mbar, Pa, kPa, MPa, and N/m2.

MKSA (meter, kilogram-force, second, ampere) – formerly known as “metric” units but are generally

being replaced by SI units. MKSA units of press include kg/cm2, mH2O, mmHg, and torr.

In meteorology, an atmosphere equals 14.7 pounds per square inch or 101.325 kilopascals.

Fluid Pressure

The press exerted by a static fluid depends only upon the depth of the fluid, the density of the fluid, and the acceleration of gravity.

The pressure in a static fluid arises from the weight of the fluid and is given by the expression

fluid pressure

Pstatic fluid = ρgh where ρ = m/V = fluid density
g = acceleration of gravity
h = depth of fluid

 

When a fluid is at rest, it exerts a force perpendicular to any surface in contact with it. This force, which is due to the continuous, random motion of molecules, is known as fluid press. Knowing the fluid pressure is essential to mechanical and hydraulic systems that use fluids move pistons and other parts.
It is usually measured in Pascals (Pa), where one Pascal is equal to one Newton per square meter (N/m2).

The fluid press is independent of the mass of the fluid but can be calculated with the density and height of the fluid.

Because of the ease of visualizing a column height of a known liquid, it has become common practice to state all kinds of pressures in column height units, like mmHg or cm H2O, etc. Press is often measured by manometers in terms of liquid column height.

Definition of Gas Press

When the molecules of gas bounce off the walls of their container, they exert a force.

The gas press is defined as the force per unit area produced by the gas. Depending on the purpose of the measurement, different units are commonly used.

The pressure gauge is an instrument that can measure the pressure of the media.
Many kinds of pressure gauges are in the industry and we can choose them according to many factors that we will talk about them in the next articles.

Saba Dejlah will offer you many kinds of gauge from the best brands in the UAE, such as WIKA, ASHCROFT,…