The SI pressure unit, one newton per square metre. Atmosphere is about 101 325 Pa, 1 mbar is 100 Pa and 1 Torr is 133.3 Pa. Vacuum standards, calibration certificates and SI-strict papers use it, and SI leak rates and throughputs come out in Pa·m³/s, where 1 Pa·m³/s equals 10 mbar·L/s. On the shop floor it is the least used of the three main vacuum units.
Heard on the job
Cal cert lists every point in pascals, so that 1E-4 Pa line is your 1E-6 mbar.
Also heard as
- Pa
Related terms
Millibar
One thousandth of a bar, equal to 100 Pa, and the default pressure unit in European vacuum work.
Torr
Pressure unit equal to 1/760 of a standard atmosphere, about 1.333 mbar, and the default in US labs and fabs.
Leak rate
Quantity of gas entering a vacuum system through a leak per unit time, usually in mbar·L/s.