K-Patents PR-33-AC - Manual (Page 38)

32 PR-33-AC instruction manual
Document/Revision No. Rev. 1.02 Effective: June, 2014
The verification result is shown on the page. Please note that reloading the page re-
moves all points. After measuring a sufficient number of points the verification may be
saved by clicking the Save verification button.
In order to avoid verification errors, please make sure:
•
the temperature has settled, i.e., the refractometer is in the ambient temperature
•
the temperature of the refractometer is between 20 °C and 30 °C
•
the prism is cleaned properly before placing the sample
•
the test liquid wets the prism properly
The temperature of the refractometer can be checked by following the temperature
measurement on the Verification page. The temperature should be constant.
The sample holder keeps the sample on the prism surface and also blocks the ambient
light from reaching the prism. The K-Patents universal sample holder PR-1012 (Fig-
ure 7.2) can be used with any K-Patents refractometer.
Figure 7.2 The K-Patents universal sample holder PR-1012
The optical image displayed on the page helps determining whether the prism is wetted
completely. The image should have a sharp corner as in figure 5.6. Note that the posi-
tion of the corner depends on the refractive index. A soft image may indicate improper
cleaning of the prism. Also, if there is not enough liquid on the prism, the image tends
to flatten. If the image changes its shape during the measurement of a single liquid,
please redo the measurement. The most likely reason is that the liquid leaks from the
sample holder.