Hitachi 902 Service Manual page 100

(b) Evasion of carry-over between reagents due to cell and washing for evasion
(I) Condition for carry-over evasion
The cell used for analysis of the specified test is not used for analysis in the
next round (after 48 cycles). Instead, it is washed for prevention of carry-over.
(II) Method of carry-over evasion
Cell is washed by aspirating detergent (detergent 1 or 2) or system water and
discharging it into a cell. At this time, washing is facilitated by stirring.
Carry-over evasion of cell is also effected during S. Stop. After completion of
washing all cells, auto stop occurs.
When stop status is set for any cause other than auto stop, cell washing for
evading carry-over due to the previous operation will not be resumed in start
from the standby status.
Execution of cell washing degrades throughput.
(III) Registration of carry-over evasion-specified pattern
Up to 10 kinds of patterns, for which the evasion of carry-over due to cell is
specified, can be registered.
(IV) Specification from screen
From the screen, the following need be specified; a carry-over giving test,
detergent set position on the reagent disk and detergent volume.
An example of specification is shown below.
[TG]
↑
Carry-
over
giving test
(CH1 to 36)
(V) Cell washing cycle
When detergent discharge volume exceeds 350 µL, detergent is discharged by
using 2 timings among the 3 timings (R1, R2, R3) for reagent aspiration and
discharge in one cycle.
(VI) Example of evading procedure
An example of carry-over evading procedure is shown below.
A to E represent tests, and W stands for washing.
Carry-over Evasion-specified Test
[38]
↑
Detergent set position
(1 to 39...ISE excluded
1 to 36,39...ISE allowed
W1... System water)
A
3 - 8
[350]
↑
Detergent discharge
volume
(50 µL to 350 µL)
Example of Evading Procedure
a-th cycle............ B
(a -1)th cycle....... D
A C.......
W E.......