Hue, Saturation, Value (HSV) Color Model

Wavelength (nm) Region name Observed

<380 Ultraviolet Invisible

380-440 Visible Violet

440-500 Visible Blue

500-580 Visible Green

580-600 Visible Yellow

600-620 Visible Orange

620-750 Visible Red

800-2500 Near-infrared Not visible

AT

AS=

K X CT X LK X CS X L

; since L is same

AT

AS=

CT

CS;

CT =AT

ASX

CS

𝓍X 100 (Conc. in 100 ml

of test sample [% conc.]; 𝓍 is ml ofsample taken)

Filter Colour of solution

Blue Red

Purple Green

Yellow Violet

Orange Blue green

Glass filter is placed in the filter slot

3/4th of cuvette is filled with distilled water and placed in the cuvette slot

Instrument is switched ‘on’ and allowed to warm-up for 4-5 minutes

Button is adjusted using ‘coarse’ and ‘fine’ knobs to give zero optical activity in the

galvanometer

Blank solution is placed in an identical cuvette and the OD is read (‘B’)

Blank solution is transferred to the original test tube

Test solution is taken in the same cuvetteand O.D. is read (‘T’)

Test solution is transferred back to theoriginal test tube

Standard solution is taken in same cuvetteand O.D. is read (‘S’)

Standard solution is transferred back to thetest tube

Cuvette is washed

Incident light strikes the grooves on the reflection grating

Many tiny spectra are formed (one from each groove)

Wave fronts are formed from these spectra (Wavefronts that are in phase,

reinforce one another whereas those out of phase, cancel each other)

A linear, parallel spectrum is formed