Tokyo Boeki Labmax 240, Service Manual

Page: 81 / 178

Service Manual
Chapter 3
3‑35
3.8. Mixing Unit 1, 2 (MU-1, MU-2)
3.8.1. Parts and Configuration
- Refer to “ASSY-10 MU-1, MU-2” for the unit assembly drawing.
- Refer to “WIRING-13 MU-1, MU-2” for the unit wiring diagram.
3.8.2. Function and Action
1. Function
MU-1 performs mixing of R1 and sample, and mixing of Cal-1 and R2
in reaction cuvette by air pressure.
MU-2 performs re-mixing before the measurement by air pressure.
2. Action (Refer to “ASSY-10” for assembly drawing.)
The shaft of stepping motor (7) slides up or down when pulse is given.
This sliding motion is transferred to mixing base (1) through ball spline (3).
Spline bearing (5) has a shade pin which shades home position sensor (6) light at
home position. This detects home position at initialization.
- Home position is at the top.
At descent, shaft of stepping motor (7) goes down, and mixing base also goes
down.
- At descent, it is moved about 1 mm lower than the distance between packing
and reaction cuvette, and this excess is absorbed by spring (10) for strict
adhesion of packing and reaction cuvette.
At ascent, shaft of stepping motor (7) goes up, and mixing base (1) also goes up.
In measurement, if mixing base will not be at the home position within the fixed
time, system gives an alarm and emergency stop.
Fig. 3-51 MU-1
Fig. 3-52 MU-2