A presentation outlining the method of colorimetry & spectroscopy. Also detailed information regarding spectrophotometer, calculation of absorbance and transmittance according to Beer & Lambert's law
14. 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
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22. AT
AS
=
K X CT X L
K X CS X L
; since L is same
AT
AS
=
CT
CS
;
CT =
AT
AS
X
CS
đ
X 100 (Conc. in 100 ml
of test sample [% conc.]; đ is ml of
sample taken)
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31. Filter Colour of solution
Blue Red
Purple Green
Yellow Violet
Orange Blue green
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38. 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 âonâ and allowed to
warm-up for 4-5 minutes
39. Button is adjusted using âcoarseâ and âfineâ
knobs to give zero optical activity in the
galvanometer
Blank solution is placed in an identical
cuvette and the OD is read (âBâ)
Blank solution is transferred to the original
test tube
40. Test solution is taken in the same cuvette
and O.D. is read (âTâ)
Test solution is transferred back to the
original test tube
Standard solution is taken in same cuvette
and O.D. is read (âSâ)
Standard solution is transferred back to the
test tube
Cuvette is washed
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72. 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