Hanna Instruments c 99 Manuel D’Utilisation

4

Absorption of Light is a typical phenomenon of interaction between
Electromagnetic Radiation and Matter. When a light beam crosses a

substance, some of the radiation may be absorbed by atoms,

molecules or crystal lattices.
If pure absorption occurs, the fraction of light absorbed depends both

on the optical path length through the matter and on the physico-

chemical characteristics of substance according to the Lambert-Beer
Law:

-log 

I

/

I

o

 = 

ε

λ

 

c d

or

A  = 

ε

λ

 

c d

Where:

-log 

I

/

I

o

=Absorbance (A)

I

o

=intensity of incident light beam

I

=intensity of light beam after absorption

ε

λ

=molar extinction coefficient at wavelength 

λ

c =molar concentration of the substance
d =optical path through the substance

Therefore, the concentration "c" can be calculated from the absorbance
of the substance as the other factors are known.
Photometric chemical analysis is based on the possibility to develop an
absorbing compound from a specific chemical reaction between sample
and reagents.

Light Life

Life of the instrument

Light Detector

Silicon Photocell

Environment

0 to 50°C (32 to 122°F);
max 95% RH non-condensing

Power Supply

2 x 9 V batteries  / 12 to 20 VDC through
voltage adapter

Auto-Shut off

After 10' of non-use

Dimensions

230 x 165 x 70 mm (9.0 x 6.5 x 2.8")

Weight

640 g (22.6 oz.)

For specifications related to each single parameter (e.g. range,
accuracy, etc.), refer to the related measurement section.