Eagle Microsystems RA1000 - Manual (Page 11)

11
E. MOTOR REPLACEMENT
1. If the motor is to be replaced, remove the striker from the motor
shaft. Install on new motor after turning the center set screw out
approximately two (2) turns.
2. Turn the side set screw in striker until it contacts the motor shaft.
The striker should be capable of sliding onto the motor shaft when
force is applied.
3. Fit the striker on to the motor so a small space is between the top
of the striker and the motor plate. Insert motor/striker assembly
into the main analyzer assembly by pushing on the motor until the
motor plate is seated on the top body.
4. Carefully remove the motor/striker from the main assembly.
Lightly tighten the side set screw in the striker. Turn in center set
screw until contact is made with the motor shaft. Now, back out
center set screw
1 /
8
to 1 /
4
turn. Loosen side striker set screw and
push up on the motor shaft. Retighten side set screw snugly.
Reinstall the motor/striker assembly with the three (3) motor
screws.
5. Rotate the motor/striker assembly by hand checking for drag or
rubbing. The motor should turn freely by hand.
6. Insert the 200 PVC spheres and rotate motor/striker again, feeling
for drag or rough spots. If drag is present, repeat Steps 2
through 5 for adjusting the striker.
7. Reassemble to panel by reversing MOTOR/STRIKER
ASSEMBLY 1, 2 and 3.
VIII. CO
2
BUFFERING
A. The CO
2
diffuser replaces the pH4 buffer solution starwheel on the right
side of the analyzer. The CO
2
diffuser may be placed on either side.
For total chlorine residual, the CO
2
diffuser is placed on the left side of the
bottom body in place of the adaptor. Solution fed by the starwheel
assembly on the right side must be potassium iodide solution only.
B. Locate the vent tube over the analyzer drain.
C. Adjust regulator and rate valve to obtain a flow of about 0.25 ppd (44
ccm) of CO
2
and check for gas leaks with soap solution. Check all tubing
connections at cylinder, regulator and analyzer and repair any leaks.
D. Set flow rate of CO
2
initially at 1 ppd (175 ccm). The actual flow rate
may be adjusted. A constant pH should be maintained.
E. CO
2
gas will buffer the sample water to maintain the pH level between 5
and 6. Calibration of the analyzer is unchanged.
CAUTION: Remember to turn off the CO
2
cylinder anytime the
analyzer is shut down.