K-Patents PR-33-AC - Manual (Page 35)

7 Instrument verification 29
© Copyright K-Patents 2014. All rights reserved.
7 Instrument verification
7.1 Refractometer verification
A company maintaining quality system according to ISO 9000 quality standards must
have defined procedures for controlling and calibrating its measuring equipment. Such
procedures are needed to demonstrate the conformance of the final product to speci-
fied requirements. The company should
−
Identify the required accuracy and select appropriate equipment for measure-
ments.
−
Establish calibration procedures including a check method and acceptance criteria.
−
calibrate the equipment at prescribed intervals against certified equipment having
a known valid relationship to nationally recognized standards. In cases where no
such standards exist, the basis used for calibration must be documented.
K-Patents verifies the calibration of all delivered instruments according to a procedure
similar to the one described below. The K-Patents quality system is ISO 9001 certified
by Det Norske Veritas.
7.2 Refractive index n
D
verification
The verification of the Sanitary OEM Refractometer calibration is made using a set of
standard refractive index liquids. In order to perform a valid verification, at least three
liquids need to be used. The verification is valid only within the refractive index range
defined by these three liquids.
The instrument recognizes automatically the following refractive index standard liquids
(the values are stated at +25 °C):
−
1.3200
−
1.3300
−
1.3400
−
1.3500
−
1.3600