Diesse Chorus - Calibration in the Quantitative Tests

Manuale operativo CHORUS
Rev. 0 del 06/2012 95
5.3.3.1 Quality control
The check routine of the QC involves processing the QC of a test batch with the corresponding strip in
the standard mode, as a sample.
Once the optical density of the QC has been determined,
OD
QC
= OD3 – OD1
Calculate
I
QC
= OD
QC
/ OD
cal
And make sure:
I
upper
≥ I
QC
≥ I
lower
Where the limits I
upper
and I
lower
are reported in the QC barcode.
If I
QC
is within the limits, the QC is accepted; otherwise, it is rejected and in the final report the sign “!“
is printed .
The QC index compared to the calibrator, and the indication of positive/negative/doubtful (P/N/D ) are
supplied.
5.3.4 C ALIBRATION IN THE QUANTITATIVE TESTS
During the quantitative tests the optical density of the calibrator for each of the test is determined by
the following formula:
OD
cal
= ( OD3 – OD1 ) * coeff
where:
• OD1 and OD3 are the optical densities determined after processing the calibrator with the
instrument.
• Coeff is the adjustment coefficient that is supplied by the calibrator and which is reported on its
label.
The OD is then compared to the acceptability upper and lower limits defined by the method
parameters. If OD
cal
complies with the parameters,
• OD
upper
< OD
cal
< OD
lower
Its value is stored in the memory; otherwise, either error Cal Low , or Cal High is generated and the
calibration fails. After that, and provided the calibration ended successfully, the Calibration Curve (CC)
is drawn up using the 4 parameters: I1, I3, I4 and I5 which can be determined from the barcode of the
calibrator and from scale dose1, dose2, dose 3, dose4 and dose5, that is defined in the method file
for that test (see fig 111).
The dose2 refers to I2 = 1 which the calibrator point corresponds to.