Search results
Results from the WOW.Com Content Network
The bar is a metric unit of pressure defined as 100,000 Pa (100 kPa), though not part of the International System of Units (SI). A pressure of 1 bar is slightly less than the current average atmospheric pressure on Earth at sea level (approximately 1.013 bar).
A vacuum gauge is used to measure pressures lower than the ambient atmospheric pressure, which is set as the zero point, in negative values (for instance, −1 bar or −760 mmHg equals total vacuum). Most gauges measure pressure relative to atmospheric pressure as the zero point, so this form of reading is simply referred to as "gauge pressure".
Other units of pressure, such as pounds per square inch (lbf/in 2) and bar, are also in common use. The CGS unit of pressure is the barye (Ba), equal to 1 dyn·cm −2, or 0.1 Pa. Pressure is sometimes expressed in grams-force or kilograms-force per square centimetre ("g/cm 2" or "kg/cm 2") and the like without properly identifying the force ...
When a particle hits a hotter surface, heat transfer will take place and the particle will gain energy. When a particle hits a colder surface, the opposite occurs. Particles that interact with a hotter or colder surface will exert a force on that surface. A Knudsen manometer uses this temperature-effect to make a plate with dual temperatures ...
The gauge may be used for pressures between 0.5 Torr to 1×10 −4 Torr. Below 5×10 −4 Torr, a Pirani gauge has only one significant digit of resolution. The thermal conductivity and heat capacity of the gas affects the readout from the meter, and therefore the apparatus may need calibrating before accurate readings are obtainable.
So, for any particular measurement of pressure head, the height of a column of water will be about [133/9.8 = 13.6] 13.6 times taller than a column of mercury would be. So if a water column meter reads "13.6 cm H 2 O", then an equivalent measurement is "1.00 cm Hg".
The SI unit of absolute thermal resistance is kelvins per watt (K/W) or the equivalent degrees Celsius per watt (°C/W) – the two are the same since the intervals are equal: ΔT = 1 K = 1 °C. The thermal resistance of materials is of great interest to electronic engineers because most electrical components generate heat and need to be cooled.
The telephone jack of manual telephone switchboards, which is the socket fitting the original 1 ⁄ 4 inch (6.35 mm) telephone plug The 1 ⁄ 4 inch (6.35 mm) phone jack common to many electronic applications in various configurations, sometimes referred to as a headphone jack