6 refractometer instrument verification – K-Patents PR-23 for K-Patents Appendix User Manual

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Installation of PR-23 Pharma Refractometer

3.6 Refractometer Instrument Verification

The operational procedure checking the refractometer calibration accuracy, linearity and
short-term repeatability and reproducibility consists of verification tests using Cargille
standard Refractive index n

liquids.

The verification of the refractometer calibration is performed whenever a new K-Patents
Laboratory Refractometer is qualified as a part of the validation process, and also if any of
the following occurs:

● There is a replacement of optical parts (prism and prism gasket).

● Refractometer readings reflect an unusual shift, or are outside of the acceptable limits,

and other means of assessing and correcting unacceptable control values fail to
identify and correct the problem.

Verification is recommended to be performed once every 12 months (or more frequently if
specified in the client’s own quality system) as a routine quality control check. Verification
is carried out using the Sample Holder PR-1012 and the set of Cargille standard refractive
index n

liquids. A set (R.I. Liquid set PR-2300) is supplied by K-Patents. The Sample Holder

PR-1012 consists of a sample receptacle with O-ring seal around the bottom aperture.

Before commencing the verification process make sure that your refractometer and sample
holder are at normal room temperature. Preferably take all components to the laboratory
already one day prior to the verification. Check the condition and expiry date of your
Standard Refractive Index Liquids and that you also have the required cleaning solution
(e.g. Isopropyl alcohol) and cleaning tissue to clean the sensor wetted surfaces and the
sample holder.

For full Sensor verification instructions see PROCESS REFRACTOMETER PR-23,
INSTRUCTION MANUAL

Section 13.

After verification of the PR-23 sensor, further verification of the Laboratory Test Cuvette and
Sensor combination can be carried out.