Search results
Results from the WOW.Com Content Network
Convert mmHg to SI units as follows: 1 mmHg = 0.133 32 kPa. Hence the normal blood pressure in SI units is less than 16.0 kPa SBP and less than 10.7 kPa DBP. These values are similar to the pressure of water column of average human height; so pressure has to be measured on arm roughly at the level of the heart.
A centimetre of water [1] is a unit of pressure. It may be defined as the pressure exerted by a column of water of 1 cm in height at 4 °C (temperature of maximum density) at the standard acceleration of gravity, so that 1 cmH 2 O (4°C) = 999.9720 kg/m 3 × 9.80665 m/s 2 × 1 cm = 98.063754138 Pa ≈ 98.0638 Pa, but conventionally a nominal maximum water density of 1000 kg/m 3 is used, giving ...
Blood pressure fluctuation (40 mmHg) between heartbeats for a typical healthy adult [44] [45] 6.3 kPa 0.9 psi Pressure where water boils at normal human body temperature (37 °C), the pressure below which humans absolutely cannot survive (Armstrong limit) [46] +9.8 kPa +1.4 psi Lung pressure that a typical person can exert (74 mmHg) [47] 10 4 Pa
In chemistry, IUPAC changed its definition of standard temperature and pressure in 1982: [1] [2] Until 1982, STP was defined as a temperature of 273.15 K (0 °C, 32 °F) and an absolute pressure of exactly 1 atm (101.325 kPa).
So, for example, pressure head might be written "742.2 mm Hg" or "4.2 in H 2 O at 59 °F" for measurements taken with mercury or water as the manometric fluid respectively. The word "gauge" or "vacuum" may be added to such a measurement to distinguish between a pressure above or below the atmospheric pressure.
The average water pressure acting against a dam depends on the average depth of the water and not on the volume of water held back. For example, a wide but shallow lake with a depth of 3 m (10 ft) exerts only half the average pressure that a small 6 m (20 ft) deep pond does.
The coefficients of Antoine's equation are normally given in mmHg—even today where the SI is recommended and pascals are preferred. The usage of the pre-SI units has only historic reasons and originates directly from Antoine's original publication. It is however easy to convert the parameters to different pressure and temperature units.
mmHg: ≡ 13 595.1 kg/m 3 × 1 mm × g 0 ≈ 1 torr ≈ 133.3224 Pa [33] millimetre of water (3.98 °C) mmH 2 O ≈ 999.972 kg/m 3 × 1 mm × g 0 = 0.999 972 kgf/m 2 = 9.806 38 Pa: pascal (SI unit) Pa ≡ N/m 2 = kg/(m⋅s 2) = 1 Pa [34] pièze (mts unit) pz ≡ 1000 kg/m⋅s 2 = 10 3 Pa = 1 kPa pound per square foot: psf ≡ 1 lbf/ft 2: ≈ 47 ...