What is compound gauge?

Simply put, a compound gauge is a device that can display both positive and negative (vacuum) pressures. You need to use a compound gauge when you are measuring a system that is exerting both positive and negative pressure on the gauge. Pressure gauges use pounds per square inch (psi) as the unit of measure.

What is compound gauge measurement range?

Compound pressure ranges include both a positive and negative pressure range in one pressure measurement device. For example you may want to purge a vessel with a vacuum pressure down to -1 bar gauge to empty it of its contents and then fill the vessel again using a pump which has a positive pressure of 5 bar gauge.

What is the difference between a compound gauge and a pressure gauge?

The major difference between compound and absolute pressure gauges is the reference point – what the gauge uses as zero. The diaphragm on a compound unit will measure vacuum pressure, which will read as a negative psi on a digital gauge, or often in inches of mercury (inHg) on an analog gauge.

What units does a compound pressure gauge?

The compound gauge measures low pressure (psig) and vacuum (inches Hg.). The high pressure gauge measures high side (discharge) pressure.

What are the types of pressure gauges?

Types of Pressure Gauges

Bourdon Tube Pressure Gauge. A Bourdon tube pressure gauge has an elastic tube that is soldered or welded on one end into a socket.
Diaphragm Pressure Gauge.
Capsule Pressure Gauge.
Absolute Pressure Gauge.
Differential (DP) Pressure Gauge.
Bellows Pressure Gauge.
Piezometer Pressure Gauge.
Case.

How do you read a vacuum pressure gauge?

Vacuum gauge is measured from ambient air pressure in the negative direction. So for example at ambient air pressure the vacuum reading is 0 bar gauge and if a suction pressure of 0.25 bar is applied, the vacuum reading will be -0.25 bar gauge.

Why is the vacuum recorded in inches of Hg in a compound pressure gauge?

When a vacuum is applied to one side of the tube, the higher atmospheric pressure pushes the mercury down, in this case, by 27 inches. Therefore, the vacuum being created is 27″Hg or 27 inches of mercury.

What are the 2 types of pressure?

There are two basic pressure types: absolute and gauge, distinguished by what pressure they are compared to, which is called the reference pressure.

What is vacuum pressure formula?

Vacuum pressure is indicated by pvacuum, and is related to absolute pressure as follows: pvacuum = pa – p, where pa is the local atmospheric pressure.

What does Hg mean in vacuum?

inches of mercury
In the U.S., the common standard to measure rough vacuum is inches of mercury (“Hg), which can be measured in two different ways. One method is as “Hg gauge (“HgV), where the scale starts at 0″ Hg (atmospheric pressure) and goes up to 29.92” Hg, which is perfect vacuum.

IS 30 in Hg high pressure?

A barometer reading of 30 inches (Hg) is considered normal. Strong high pressure could register as high as 30.70 inches, whereas low pressure associated with a hurricane can dip below 27.30 inches (Hurricane Andrew had a measured surface pressure of 27.23 just before its landfall in Miami Dade County).

What does a compound pressure gauge measure in?

Also known as compound gauges, these measure both pressure and vacuum. Use them with pumps, filters, regulators, compressors, and in suction and process lines. Gauges with ABS plastic case are more corrosion resistant than gauges with steel case.