Initial setting up
Power supply
All Abbe 60 refractometers are supplied with an external power supply, which should be plugged
into the sealed power connector on the side of the instrument.
The power supply itself is connected to the mains supply by a moulded mains lead, which is also
supplied with the instrument.
Connect the mains lead to the mains supply and switch on the supply.
Early models only, with serial numbers prior to A01051
Switch the instrument on by pressing down the power switch, located next to the instrument
power connector.
Altering the focus of the telescopes
To alter the focus of either of the telescopes, move the lens cap away and towards the main body
of the instrument until the scale and the crosswires are well defined. To help the lens cap move,
twist it whilst adjusting the focus.
Below are examples of the views that you will get when looking down each of the telescopes (the
scale view is that of a Direct Reading instrument).
Scale view Field view
Adjusting the upper prism box shutter
The upper prism box shutter has two separate functions.
The first is to control the amount of light from the light source that is passed through the sample;
this is necessary to adjust the contrast between the light and dark parts of the borderline.
The other use is to limit unwanted, ambient light entering the prism. If you are using the integral
L.E.D. light source on a Direct Reading instrument, it is recommended that the shutter should
initially be open about 2mm. This will restrict the amount of white light entering the sample. When
using a spectral light source the shutter has a lesser effect, as the light source will be able to flood
the sample with light.
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