Absolute pressure refers to the absolute value of theforce per-unit-area exerted on a surface by a fluid. Thereforethe absolute pressure is the difference between the pressure at a given point in a fluid and the absolute zero of pressure or a perfect vacuum.Gage pressure is the measurement of the difference between the absolute pressure and the localatmospheric pressure. Local atmospheric pressure can vary

depending on ambient temperature, altitude and local weather conditions.

Pabs= Atmoshperic pressure + gauze pressure

There are two types of fluid systems; static systems and dynamic systems. As the names imply, a static system is one in which the fluid is at rest and a dynamic system is on in which the fluid is moving.The pressure measured in a static system is static pressure.The pressure increases with depth in the fluid and acts equally in all directions. The increase in pressure at a deeper depth is essentially the effect of the weight of the fluid above that depth. The pressure in a static liquid can be easily calculated if the density of the liquid is known. The absolute pressure at a depth H in a liquid is defined as:

Pabs = P + (ρ x g x H); P is the external pressure at the top of the liquid. For most

open systems this will be atmospheric pressure.For fluids like air column, the product of (ρ x g x H) is negible, as does not have any effect. Then in that case, absolute pressure is equal to P itself.

The concept of static pressure comes into picture, for liquid fuels, where density has appropriate value.

In case of gaseous fluids like air in air craft applications, the concept of stagnationpresure is an important patamter, which is equal to

Stagnation pressure= Static pressure + dynamic pressure, in which dynamic pressure is a fucntion of density and velocityof fluid, while static pressure is calculated from application of altitude and pressure relations. 

They are not the same. The absolute pressure includes the dynamic pressure, that which is associated with motion in a fluid. For example, a particle falling in a fluid will feel a hydrostatic pressure due to its depth in the fluid + a pressure associated with its movement in the fluid that contributes to the drag. The static pressure comes into play in buoyancy calculations, as the forces of gravity and that arising from pressure for a non-moving object have to counter each other. I hope this helps. Best, Emmanuel

The pressure at a given depth in static liquid is a result of the weight of liquid acting on unit area at that depth plus any pressure acting on the surface of the liquid

P=Patm +densityxgh 

The pressure due to liquid alone  (that is gauze pressure) at a given depth depends only upont the density of the liquid (row) and the distance below the surface below the surface of the liquid, h

P= Density xgh

The absolute pressure at a depth, h in a liquid open to atmosphere is increased by the pressure of the atmsophere pusing down on the surface of the liquid

P= Patm + density xgh

@David, thanks for the info.

@Emmanuel, thanks for the info.

@ Maddali, so you are saying both static and absolute pressure are the same in magnitude.

Absolute pressure= Gauze pressure+ atmoshperic pressure

Static pressure= Presssure acting on the surface + gauze pressure  

Stagnation pressure= Static pressure + dynamic pressure

Dynamic pressure can be calcualed from the concepts of density and velocity,

If no pressure intensity is acting on the surface, pressure will be considered as atmospheric pressure, ex: open water tank. (many cases it need not be)

@Maddali, thank you sir.

Now it makes it clear. Thank a lot sir.

@Borisyuk, thank for the update sir.

@ Maddali sir, I have a doubt. Can you throw a better light. 

According to your previous comment the difference between the static and absolute pressures, are static pressure has a pressure acting on the surface and the absolute pressure has the atmospheric pressure.

But literally both the pressure acting on the surface and the atmospheric pressure are the same, right. Or is it like some other additional pressure.

thanks!

The static pressure, it is possible to express like absolute, or also: 1. Manometric if the static pressure is major that the atmospheric pressure 2. Or as of emptiness, if the static pressure is less that the atmospheric pressure. In other words, the static absolute pressure takes as a reference zero the pressure .

@ Juan, thanks for the info.

@ Chennakessava, thanks for the update

Dear Rajesh, 

The following information may be useful for your studies .Y ou can visualize diagrams also.

Understanding Pressure and Pressure Measurement by  David Heeley

www.freescale.com/files/sensors/doc/app_note/AN1573.pdf

Dear  Rajesh, Answer to your query lies in the combination of Pascal's Law, which defines the "static pressure" as " head of a liquid column at a location on a body submerged in a non-moving ( static) fluid and the Bernoulli's equation, which defines the pressure as energy in three forms : Pascal's head , kinetic head and geodetic head ( locational head, with the consideration of all bodies in the atmosphere submerged in non-flowing air . So, in effect, pressure at any point on a body is being exerted by two static fluids at the same time: the working fluid and the stagnant air outside. When we deal with liquids as working fluids, the Pascal's head and the geodetic head ,both, are significant, and the Pascal's static pressure and the absolute pressure ( pressure measured with respect to vacuum) will be different in quantum.. But, when we deal with gaseous media as working fluid, the static pressure and the absolute pressures will be nearly equal, ( geodetic head being very small ), the kinetic head not being take into account. 

Absolute pressure is used in measurement any kind of pressure either static or dynamics using gauges. It equals gauge pressure adding one bar.

This is easiest explained for gases, I think. Absolute pressure refers to the thermodynamic pressure (at a given density and temperature) of the gas (microscopically: momentum exchanged by gas molecules with each other out the boundaries of e.g. a container), whereas "gauge" or differential pressure refers to the difference between this pressure and the pressure of the atmosphere. Static pressure is a concept used to differentiate between absolute pressure and the "total" pressure experienced by surfaces orthogonal to the direction of flow, where a "dynamic" pressure is experienced on top of the static one. Look for "Pitot tube" as a simple illustration of the difference. One may argue that this "dynamic pressure" should not even be called a pressure as it is kinetic energy in a specific direction whereas pressure acts equally in all directions. In that sense, pressure, "static" pressure and "absolute" pressure are all the same. For measured values it depends how and where you measure and how you separate pressure from other contributions (see Pitot tube).

From aerodynamics perspective, static pressure and absolute pressure are same. Depending on this air pressure, the Altimeter sensor determines the altitude of the aircraft.

But at ground level, in a closed container, additional static head of the liquid needs to be taken into account if the fluid has a density much larger than air. Air pressure (1 atm.) then should be added to this gauge pressure to obtain the absolute pressure.

In a flowing system, as already pointed out both static (Ps) and dynamic pressure (rho x v^2/2) must be added to obtain the total local gauge pressure.

Probably the best way to visualize the pressure is energy/volume since calculating energy would automatically include the potential and kinetic energy which correspond to the static and dynamic pressure respectively.

Absolute pressure refers to the absolute value of theforce per-unit-area exerted on a surface by a fluid. Thereforethe absolute pressure is the difference between the pressure at a given point in a fluid and the absolute zero of pressure or a perfect vacuum.Gage pressure is the measurement of the difference between the absolute pressure and the localatmospheric pressure. Local atmospheric pressure can vary

depending on ambient temperature, altitude and local weather conditions.

Pabs= Atmoshperic pressure + gauze pressure

There are two types of fluid systems; static systems and dynamic systems. As the names imply, a static system is one in which the fluid is at rest and a dynamic system is on in which the fluid is moving.The pressure measured in a static system is static pressure.The pressure increases with depth in the fluid and acts equally in all directions. The increase in pressure at a deeper depth is essentially the effect of the weight of the fluid above that depth. The pressure in a static liquid can be easily calculated if the density of the liquid is known. The absolute pressure at a depth H in a liquid is defined as:

Pabs = P + (ρ x g x H); P is the external pressure at the top of the liquid. For most

open systems this will be atmospheric pressure.For fluids like air column, the product of (ρ x g x H) is negible, as does not have any effect. Then in that case, absolute pressure is equal to P itself.

The concept of static pressure comes into picture, for liquid fuels, where density has appropriate value.

In case of gaseous fluids like air in air craft applications, the concept of stagnationpresure is an important patamter, which is equal to

Stagnation pressure= Static pressure + dynamic pressure, in which dynamic pressure is a fucntion of density and velocityof fluid, while static pressure is calculated from application of altitude and pressure relations. 

@ Maddali , thanks for the info and link.

@ Krishna, thanks for the info.

@Jan, thanks for the info.

@Subhasish, thanks for the info.

@ Maddali sir, this makes it clear.

thanks for the effort. Its really helpful.

Pressure is defined as the force per unit area exerted on a surface. Pressure is measured and expressed in two different systems: relative and absolute. Absolute pressure is the total force per unit of area exerted on a surface and it is defined in terms of absolute zero. Static pressure refers to the force per unit area exerted by a fluid on a surface in a static system. A static system is one in which the fluid is at rest.

The static pressure can be absolute or relative, depending on whether one takes into account the pressure of the external medium. In the case of considering zero pressure of the external medium then reading the static pressure will be relative. Therefore in the opposite case it is equal to the absolute.

@Ronny, thanks for the update.

@Borisyuk, thanks for the update.

It is expain in all text.....read it yourself

•  Static pressure ( pressure measured, while neglecting the velocity effects) if measured with a gauge or with reference to another pressure , is called "gauge pressure". Add the value of the reference pressure to the gauge pressure, it becomes "Absolute Pressure".
• In other words, if the pressure at a location , neglecting the velocity effects if any, is measured with reference to "vacuum", then the values of the measured static pressure and the absolute pressure will be equal. 
• I hope, I have been able to clear the dilemma.

@ krishna, thanks for the info.