Specification of Aschcroft Pressure Gauge
Aschcroft Pressure Gauge is a barometer of air pressure gauge
What is a pressure gauge?
A pressure gauge is a device used to measure fluid pressure (gas or liquid) in a closed tube. The units of this pressure gauge are psi (pounds per square inch), psf (pounds per square foot), mmHg (millimeter of mercury), inHg (inch of mercury), bar, atm (atmosphere), N / m ^ 2 ( pascal).
Before stepping into the discussion about pressure gauge, it's good to discuss the pressure itself. Pressure is divided into several, including:
Absolute Pressure
that is the pressure calculated based on the reference pressure of 1 atm. Absolute pressure is better known as PSIA. (PSIA = PSIG + Patm).
Pressure gauge
that is a positive pressure against a reference pressure of 1 atm, which means that this pressure is greater than 1 atm. The gauge pressure is better known as PSIG. In this condition, PSIG> 1 atm.
Vaccum pressure
that is negative pressure to atmospheric pressure or it could be said that the vaccum pressure is under atmospheric pressure so it is negative. PSIA <1 atm.
Hydrostatic pressure
namely the pressure that occurs under water. This pressure occurs because of the weight of water which makes the liquid pressure. The pressure of a liquid depends on the depth of the liquid in a space and gravity also determines the pressure of the water. This relationship is formulated as follows: "P = ρgh" where ρ is the period of type of liquid, g (10 m / s2) is gravity, and h is liquid depth.
Differential pressure
that is, pressure measured against other pressures. PSID amount.
To measure pressure / pressure there are several measuring elements, namely:
1. Bourdon Tube.
Bourdon tube is a tube with a closed end which when given pressure, the shape will stretch according to the amount of pressure given, and can return to its original shape. There are several forms of bourdon tubes, namely:
Bourdon C: Bourdon tube with a shape resembling the letter "C".
Bourdon Spiral: Bourdon tube with a spiral shape.
Bourdon Helix: Bourdon tube with a helical shape.
2. Bellows
Bellows are pressure gauge elements that are capable of deflection. Bellows are accurate to be used to measure the pressure of gage (Pgage) with a range between absolute zero to 350 kPa. Consists of a metal tubing that can expand in the direction of its length. Bellows with a wide diameter can read low pressure better than bourdon tube.
3. Diaphragm
The diaphragm is a flexible disk (flexible disc) that can be thin (flat diaphragm) or has concentric folds (corrugated diaphragm) as shown in the picture above.
4. Diaphragm capsules
The capsule is composed of two diaphragms which are welded together around the circle. The sensitivity of capsules increases in proportion to its diameter, which is generally conventional in diameter varying from 25 to 150 mm.
Various kinds of pressure gauge products in the field, using one of the four elements mentioned above. A pressure gauge is installed to measure the pressure inside a pipe or tank. The types of pressure gauges can be mechanical or digital pressure gages.
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