K-Patents PR-01-S - Manual (Page 38)

INSTRUCTION MANUAL FOR K-PATENTS PR-01-S (-AX/FM/CS) DOCUMENT/REVISION No. INM 1/14
Effective: May 15, 2009
36
5.3. FIELD CALIBRATION
The most accurate calibration is made under normal process conditions employing the users standard
laboratory determinations of sample concentration. K-Patents provides a FIELD CALIBRATION service
to optimize calibration constants based on data supplied by the user.
The user should systematically record calibrating data by the CALIBRATION DATA REPORT (last page
in this manual). Each data point consists of:
LAB% Sample concentration determined by the user.
From refractometer display (Section 2.7):
CONC% Measurement in concentration units
TEST Number of photocells on the light side of the optical image
(= primary measurement)
TEMP Process temperature measurement in centigrades
Note: A data point is of use for calibration only when the diagnostic message is Normal operation. Do not
take samples during the prism wash. A data point is useful even if the concentration value is outside the
range of the output current.
To achieve an accurate calibration the sample has to be taken correctly:
– The sampling valve and the refractometer should be installed in the same place in the process.
– Take the sample and read the display at exactly the same time!
– For hot samples use a tight container (avoid evaporation)
– Run the sample before starting to collect (avoid old sample that has remained in the sampling valve).
A completed CALIBRATION DATA REPORT with 5 - 15 calibration points covering the measurement
range can be sent to K-Patents or local K-Patents representative by fax. A computer analyses of the data
will be made at K-Patents and an optimal calibration data will be faxed to the user.