Gauge pressure is what you get when you take the reading from your tire pressure gauge. Absolute pressure is the pressure inside your tires plus the atmospheric pressure, which is roughly; 14.7 psi, 101.3 kPa (kilo-Pascals), or one atmosphere. Absolute pressure measures all of the pressure on your tires, inside and out, whereas gauge simply measures the pressure inside the tire.
-14.7psig is the gauge pressure of an absolute vacuum.
No. We need to know exactly what is meant by gage here. A piston tyre gauge measures pressures relative to atmospheric. A mercury barometer measures absolute pressure. A gauge that involves uncoiling of a coiled tube will measure absolute pressure (it will have to be calibrated). But a manometer which is open to the atmosphere on one arm will measure pressures relative to atmospheric pressure so the real pressure is the two added together.
No common vacuum units that I know of use negative values for a vacuum. Although pressure is an absolute quantity, everyday pressure measurements, such as for tire pressure, are usually made relative to ambient air pressure. In other cases measurements are made relative to a vacuum or to some other ad hoc reference. When distinguishing between these zero references, the following terms are used: Absolute pressure is zero referenced against a perfect vacuum, so it is equal to gauge pressure plus atmospheric pressure. Gauge pressure is zero referenced against ambient air pressure, so it is equal to absolute pressure minus atmospheric pressure. Negative signs are usually omitted. Differential pressure is the difference in pressure between two points. The zero reference in use is usually implied by context, and these words are only added when clarification is needed. Tire pressure and blood pressure are gauge pressures by convention, while atmospheric pressures, deep vacuum pressures, and altimeter pressures must be absolute. Differential pressures are commonly used in industrial process systems. Differential pressure gauges have two inlet ports, each connected to one of the volumes whose pressure is to be monitored. In effect, such a gauge performs the mathematical operation of subtraction through mechanical means, obviating the need for an operator or control system to watch two separate gauges and determine the difference in readings. Moderate vacuum pressures are often ambiguous, as they may represent absolute pressure or gauge pressure without a negative sign. Thus a vacuum of 26 inHg gauge is equivalent to an absolute pressure of 30 inHg (typical atmospheric pressure) − 26 inHg = 4 inHg.
Absolute pressure is simply the addition of the observed gage pressure plus the value of the local atmospheric pressure.
but i think the absolute pressure is P(pressure)/{p(density)*g(gravity)}
gauge
i need to explain what an absolute pressure gauge measures
The gauge pressure is the absolute pressure minus atmospheric pressure. If atmospheric pressure is considered to be 101 kPa, then the gauge pressure would be 219 kPa.
absolute pressure; gauge pressure; atmospheric pressure...
if the gauge pressure is 206 kPa, absolute pressure is 307 kPa
If a gas has a gage pressure of 156 kPa its absolute pressure is approximately?
The gauge pressure is the difference between the absolute pressure and atmospheric pressure. If atmospheric pressure is approximately 101.3 kPa, then the gauge pressure would be 448.980 kPa (550.280 kPa - 101.3 kPa).
44.7 psi
The gauge pressure would be 448.955kPa.
Absolute
Bourdon's tube pressure gauge cannot be used to measure negative pressure. This is because absolute pressure must be measured and the Bourdon gauge only indicates the gauge pressure.
-14.7psig is the gauge pressure of an absolute vacuum.