Definition of spectrometer. 1  1 : an instrument used for measuring wavelengths of light spectra. 2  2 : any of various analytical instruments in which an emission (as of particles or radiation) is dispersed according to some property (as mass or energy) of the emission and the amount of dispersion is measured nuclear magnetic resonance spectrometer.
1 bar is equal to 1000 millibars. Just like how there are 1000 millilitres in a litre, and 1000 milliseconds in a second. 1 millibar = 0.001 bars.
But the inch is really not a unit of pressure, or force per area. It is a unit of length. So a metric unit has been defined to describe normal atmospheric pressure, called a bar, and the instrument becomes a barometer.. Actually, normal average sea-level pressure is 1.01325 bars, or 1,013.25 millibars (mb).The millibar is a commonly used unit of pressure.o a metric unit has been defined to describe normal atmospheric pressure, called a bar, and the instrument becomes a barometer.. Actually, normal average sea-level pressure is 1.01325 bars, or 1,013.25 millibars (mb).