torr(redirected from Micrometer of mercury)
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A unit of pressure sufficient to support a 1-mm column of mercury at 0°C against the standard acceleration of gravity at 45° north latitude (980.621 cm/s2); equivalent to 1333.224 dynes/cm2, 1.333224 millibars, 1.35951 cm of H2O, 133.3224 newtons/m2 (or Pa); 1 atmosphere (atm) equals 760 Torr.
Etymology: Evangelista Torricelli, Italian physicist, 1608-1647
a unit of pressure equal to 1333.22 dynes/cm2, or 1.33322 millibars. One torr is the pressure required to support a column of mercury 1 mm high when the mercury is of standard density and subjected to standard acceleration. These standard conditions are 0° C and 45° latitude, where the acceleration of gravity is 980.6 cm/sec2. In reading a mercury barometer at other temperatures and latitudes, corrections commonly exceeding 2 torr may be required to compensate for the thermal expansion of the measuring scale used.
Torricelli,Evangelista, Italian scientist, 1608-1647.
torr - a unit of pressure.
torricellian vacuum - a vacuum above the mercury in a barometer tube.
n a unit of pressure equivalent to 0.001316 atmosphere; named after the physicist Torricelli. Also called