6
Instrument Layout
Test Tube holder
Screen
“Read Sample” button
“Menu” button
“Blank Sample” button
“On/Off” button
7
2
BACKGROUND INFORMATION
Introduction to Colorimetric Measurement
Palintest tests are based on measuring the intensity of
colours
produced
by
Palintest
reagents
and
using
Palintest photometers to measure that intensity of colour.
This is colorimetry and can be defined as any technique
used to evaluate an unknown colour in reference to
known colours.
To avoid subjective measurement between test samples
and colour standards, a colorimeter can be used for
quantitative measurement of the amount of coloured light
absorbed by a sample (with reagents added) in reference
to a untreated sample (blank).
White light is made up of many different wavelengths of
light.
A colorimeter passes a white light beam through an
optical filter which transmits only one particular band
of wavelength of light to the photodetector where it is
measured.
The difference in the amount of coloured light transmitted
by a colourless sample (blank) and the amount of coloured
light transmitted by a coloured sample is a measurement
of the amount of coloured light absorbed by the sample.