Siemens ADVIA 1800, Operator'S Manual, Page: 27 / 222

System Overview 27
After a cuvette is washed by one nozzle, it moves to the next until washing is complete.
While the DTT rotates, the DWUD is in the up position.
1 Dilution Washer (DWUD)
Figure 1-19. Dilution tray wash mechanism
DPP probe features
Clot detection operation
The clot detection system utilizes a pressure transducer to monitor the pressure in the
sample dilution probe line (DPP) for a complete obstruction during the sample aspiration
and dispensation cycle. Clot detection is available on the DPP line only.
IMPORTANT
Normal sample handling guidelines call for operators to screen samples manually for the
presence of clots prior to placing them on the analyzer. The clot detection feature is
intended to detect 95% of the samples that are likely to cause complete sample probe
obstruction. Clot detection does not eliminate the need to prescreen samples for clots.
Partial DPP obstructions are not detected.
The system monitors the pressure at the transducer at four points during the sampling
cycle and displays an error if a predefined limit is exceeded at any of the checkpoints. A
fifth check occurs at the start of sampling.
•
You can toggle clot detection on and off.
•
You can deactivate clot detection for calibrator and control materials that require
aspirations from the STT or CTT.
•
Clot detection is active for samples aspirated from the STT, CTT, rack handler, or
other LAS device. Clot detection is inactive when the DPP aspirates from the DTT.
•
The clot detector is active each time the DPP probe enters a sample, even when
multiple aspirations are required. If the DPP samples three times and detects a clot on
the first aspiration, it will continue to aspirate two more times. It will flag all the tests
in the first aspiration, but not the second or third. This may cause partial results to be
reported.All the tests on that sample (from all three aspirations) must be repeated. .