7
FUNCTIONAL DESCRIPTION
1) Liquid Crystal Display
2) Cuvet Holder
3) Cuvet alignment indicator
4) ON/OFF key
5) ZERO key
6) READ key
7) CAL CHECK key
A microprocessor controlled special tungsten lamp emits radiation which is first optically
conditioned and beamed to the sample contained in the cuvet. The optical path is fixed by the
diameter of the cuvet. Then the light is spectrally filtered to a narrow spectral bandwidth, to
obtain a light beam of intensity
I
o
or
I
.
The photoelectric cell collects the radiation
I
that is not absorbed by the sample and converts
it into an electric current, producing a potential in the mV range.
The microprocessor uses this potential to convert the incoming value into the desired measuring
unit and to display it on the LCD.
The measurement process is carried out in two phases: first the meter is zeroed and then the
actual measurement is performed.
The cuvet has a very important role because it is an optical element and thus requires particular
attention. It is important that both the measurement and the calibration (zeroing) cuvets are
optically identical to provide the same measurement conditions. Whenever possible use the same
cuvet for both. It is necessary that the surface of the cuvet is clean and not scratched. This to
avoid measurement interference due to unwanted reflection and absorption of light. It is
recommended not to touch the cuvet walls with hands.
Furthermore, in order to maintain the same conditions during the zeroing and the measuring
phases, it is necessary to close the cuvet to prevent any contamination.
18
Battery replacement must only take place in a
non-hazardous area.
Simply slide off the battery cover on the back of
the meter. Detach the battery from the terminals
and attach a fresh 9V battery while paying
attention to the correct polarity. Insert the battery
and replace the cover.
9V
SLIDE
OFF
BATTERY REPLACEMENT