K-Patents PR-03 - Manual (Page 117)

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D Instrument verification ISO 9000 111
D Instrument verification ISO 9000
A company that maintains a quality system according to ISO 9000 quality standard must have defined
procedures for controlling and calibrating its measuring equipment. This is required for demonstrating the
conformance of the final end product to the specified requirements. The company should:
− identify the required accuracy and select an appropriate equipment for the measurements
− establish calibration procedures, including check method and acceptance criteria.
− calibrate the equipment at prescribed intervals against certified equipment having a known valid rela-
tionship to nationally recognized standards. When no such standard exists, the basis used for calibration
should be documented.
This text provides a valid method for meeting the above requirements with a K-Patents inline refractometer
system. K-Patents quality system is certified against the ISO 9001 by Det Norske Veritas. K-Patents verifies
the calibration of all delivered instruments according to a similar procedure as described in this section.
Definitions
Refractive Index (R.I.) calibration
Calibration of PR-03 with standard Refractive Index liquids:
As a result of calibration procedure, a set of R.I. parameters are calculated: RIBias, RIGain, RISquare and
RiCube. These parameters define the calibration polynomial, used for refractive index measurement with a
reference temperature of 25
◦
C.
The Refractive Index (R.I.) calibration can be traced to national standard NIST 1823, whenever certified
standard R.I. liquids are used in the calibration.
Accuracy of R.I. calibration
Maximum deviation accepted in R.I. calibration:
The total acceptable deviation for PR-03 is R.I. 0.0006. This comes from the accuracy of PR-03
(R.I. 0.0002) and from the accuracy of the standard R.I. liquids used in the calibration (R.I. 00002).
Repeatability of the R.I. calibration
Deviation from the latest R.I. calibration of PR-03:
The repeatability of PR-03 is R.I. 0.0002. This can be verified as described in the following section.
Verification of Refractive Index (R.I.) calibration
The R.I. calibration can be verified with three certified standard R.I. liquids as follows: