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.
There is no 'standard' bar of gold. Bars come in a range of weights, starting from 1 gram to 1000 grams generally. I have handled the following bars: 1 gram, 2 grams, 5 grams, 10 grams, 11.664 grams (1 tola). 20 grams, 31.1 grams (1 Oz.), 50 grams, 58.32 grams (5 tolas), 100 grams, 311 grams (10 Oz.), 500 grams and 1 kg.