Reaction Limit Level Check; Relationship Between Alarm Name And Photometric Point; Automatic Correction Of Reaction Limit Level - Hitachi 902 Service Manual

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Reaction Limit Level Check

When concentration or enzyme activity is abnormally high in a rate assay test, correct
data is unobtainable because the substrate or coenzyme in reagent is consumed
completely. Therefore, the upper or lower reaction limit absorbance is set for check .
Check is made on the absorbance at the main wavelength alone.
< Relationship between Alarm Name and Photometric Point >
When 4 points or more over the specified photometric range are within the reaction limit,
measurement is carried out normally. In case no point, 1 point or 2 points are within the
reaction limit, a reference value is obtained depending on an absorbance change
between the first two points. In case 3 points are within the reaction limit (with comment
LIMT2), the value obtained depending on an absorbance change among the first three
points is printed as a reference value.
ABS.
Input photometric range
(with comment LIMT0)
ABS.
Input photometric range
(with comment LIMT2)
< Automatic Correction of Reaction Limit Level >
The instrument corrects the input reaction limit level by adding an absorbance value due
to sample turbidity, etc.
Reaction limit level = Input reaction limit absorbance value + (L
L : Sample absorbance at photometric point 1
1
L : Reagent blank absorbance at photometric point 1
B
When L - L
1
Reaction limit level
Time
Time
Fig. 2-1 Reaction Limit Level Check
≤ 0, automatic calibration will not be performed.
B
ABS.
Input photometric range
(with comment LIMT1)
ABS.
Input photometric range
(with comment LIMT2)
2 - 53
Time
Reaction limit
level
Time
- L )
1 B