LABEC M-MIA-CC - Manual (Page 32)

Ultrasonic milk analyser
Operation manual 23.08.10 30/98
6.2.2.1. If the received differences are relatively constant value for samples
with different content of the analyzed parameter, it is necessary to make
correction.
For example
М% of the reference samples:
2,20 3,00 3,80 4,60 5,20
М% average when measuring
with
the analyser: 2,38 3,17 4,01 4,79 5,42
Difference: 0,18 0,17 0,21 0,19 0,22
Conclusion: the difference is relatively constant value and correction is
possible to be done with – 0,2 % (see Corrections, p. 6.3.3)
6.2.2.2. If the differences are not a constant value it is necessary recalibration
to be done.
For example.
М% of the reference samples:
2,20 3,00 3,80 4,60 5,20
М% when measured with the
analyser:
2,02 2,93 3,76 4,75 5,44
Difference: -0,18 -0,07 -0,04 0,15 0,24
Conclusion: It is obvious that the difference is variable value and
recalibration has to be done (See Recalibration, p.6.4).
6.3. Making corrections
6.3.1. Possible corrections, limits and changing steps
Every parameter from each calibration may be separately corrected. Below is
the table with possible corrections, limits and changing steps:
Parameter Increasing Decreasing Step
FAT 0.95% 0.95% 0.01%
SNF 4.75% 4.75% 0.05%
Density 4.75% 4.75% 0.05%
Lactose 0.95% 0.95% 0.01%
Salts 0.95% 0.95% 0.01%
Proteins 0.95% 0.95% 0.01%
Added water 9.00% 9.00% 1.00%
Sample’s temperature 9.90 o С 9.90 o С 0.1 o С
6.3.2. Preparing the analyser for mode Corrections