Sentinel Performance Solutions Ltd, The Heath Business & Technical Park
Runcorn, Cheshire, WA7 4QX T: +44 (0) 1928 588330
F: +44 (0) 01928 588368
Page 3 of 4
june-10
Technical Information
Instructions for use of the
Refractometer
Operation
Calibration Check
1. Open the daylight plate and place 2-3 drops
of distilled water on the blue glass prism
using the plastic dropper. Close the daylight
plate so that the water spreads across the
entire surface of the prism without air bubbles
or dry spots.
2. Allow the sample to rest on the prism for
approximately 30 seconds to allow the
sample to adjust to the temperature of the
refractometer.
3. Hold the daylight plate in the direction of a
light source and look into the eyepiece. A
circular field with graduations will be visible.
(You may have to focus the eyepiece to
clearly see the graduations). The upper
portion of the field should be blue and the
lower portion should be white.
4. If the boundary between the blue and white
does not meet on the zero graduation, which
is at the bottom of the propylene glycol scale,
then calibration will be required. Adjust the
calibration screw until the boundary meets at
the zero graduation.
Sample Check
1. Ensure that the sample is cooled to ambient
temperature and repeat steps 1 – 3 above.
Take the reading at the point where the blue
and white boundary occurs on the propylene
glycol scale. This will represent the antifreeze
content of the thermal fluid.
Warning – Maintenance
1. Do not expose the instrument to damp
working conditions and do not immerse the
instrument in water. If the instrument
becomes foggy, water has entered the body
of the instrument and the supplier needs to
be contacted.
2. Do not measure abrasive or corrosive
chemicals with this instrument. They can
damage the prism’s coating.
3. Clean the instrument between each
measurement using a soft, damp cloth.
Failure to clean the prism on a regular basis
will lead to inaccurate results and damage to
the prism’s coating.
4. This is an optical instrument. It requires
careful handling and storage. Failure to do so
can result in damage to the optical
components and its basic structure.
Instructions for use of the pH Sticks
1. Briefly dip the pH stick in the sample of
thermal fluid. If the sample is weakly buffered
leave test stick in the sample until colour no
longer changes.
2. Compare the colour of the two pads on the
bottom of the strip with the chart on the side
of the pack.
SolarCheck Survey Sheet
The “SolarCheck Survey Sheet” is available free
on the Sentinel Performance Solutions Ltd web
site at
