Terumo BCT Trima Accel, Руководство по обслуживанию

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Figure 2-14: RBC detector block diagram
The control CCA sends 12 V and the drive signal to the RBC detector. A sense line comes from the RBC
detector to the control CCA. When the sense line is detecting RBC contamination, the signal is low
when RBC is not sensed and high when RBC is sensed. When the sense line is detecting cassette type, the
signal is a low number for a black stamp, which absorbs more light, and a higher number for a white
stamp. These numbers are recorded in the dlog file. This number can be calibrated and is used to adjust
the duty cycle for the LEDs to adjust light intensity. Every time a cassette is loaded, the RBC detector
auto-calibrates, storing a number in a register on the control CCA to balance the red/green ratio at 1.
This number adjusts the duty cycle of the LEDs to balance the reflectance (these numbers are also in the
dlog file). When RBC contamination is detected, the device generates an alarm that can be cleared and
adjusts the valve position and the pump speed to purge the line of RBC and continue on.
Leak Detector
The leak detector senses fluid leaks from the disposable tubing set. It is mounted on the back wall of the
centrifuge basin.
The leak detector consists of a printed wiring board (PWB) with traces that act like a variable resistor.
When fluid is deposited on the leak detector, a change in resistance is detected, and an alarm is generated
by the control system. The normal voltage range of the leak detector is 2.0 V to 3.0 V. Below 2.0 V
indicates a fluid leak. Above 3.0 V indicates an open circuit. During startup tests and prior to loading a
tubing set, the system checks the ability of the leak detector to operate normally.
Sensor System
Trima Accel
®
Automated Blood Collection System • Service Manual 2-15