When the sample is colored and/or
extremely cloudy, the refractometer
occasinally shows such phenomena
as the field of view is dark and
difficult to see, the boundary line is
unclear or invisible. In such the
event, illuminate the lighting hole in
the secondary prism with another
light source.
35
11.
Situations that may require additional attention
a)
b)
(1) When measuring colored or
cloudy sample
Example: Sodium lamp, lighting
apparatus for microscope,
etc.
When the sample is colored thick,
there is the reflecting measurement
method as a means to measure
such the sample.
For measuring a sample in this way,
remove the cap of the lighting hole
for the reflecting measurement and
illuminate the sample with indirect
light through this hole. Through this
measurement,
turn
off
the
illumination for the secondary prism,
otherwise, the dark half and the
bright half of the field are replaced
with each other.
a)
b)
The harder a sample is, the more
difficult measurement is. Because, the
gap between the main prism and
secondary prism is widened with
increase of sample's hardness, and
lighting accordingly becomes worse.
When measuring pasty sample, spread
it on the main prism surface as thin as
possible with a spatula or the like so
that the gap between the two prisms
becomes small.
It is much more difficult to measure a
pasty sample containing different
materials that are kneaded or tempered
together; such as peanut butter, bean
jam, unclear oily samples, and other
insoluble
pasty
samples.
For
measuring such pasty samples, it is
advised to try to mix the ingredients as
completely as possible and slightly heat
the sample approximately to 40
℃
to
soften it for carrying out measurement
more easily.
(3) Measurement method of
pasty sample
(2) Discoloration or "Burning" of
the main prism
Heavily discolored surfaces may not be
removed with this method. Please
contact your ATAGO distributor.
Discoloration or burning may appear on
the main prism as a result of a chemical
reaction or prolonged exposure to high
temperature samples. The discoloration
appears as a slightly blue-purple layer or
"rainbow" effect.
This damage may cause a blurry field of
vision, making it difficult to see the
boundary line. Light discoloration may be
removed by the Prism Polishing Powder.
①
Stir water into the Prism Polishing
Powder to make a smooth paste.
②
Using a cotton swab, applying light
pressure, rub the paste with an up and
down motion (non-circular) on the main
prism surface. Check the progress after
about 20 to 30 strokes. If discoloration is
still visible, repeat the process with
another 20 to 30 strokes to remove
remaining discoloration.
Pert name
RE-99402
Pert No.
Polishing Powder
