Hitachi IJ UX Service Manual page 171

(D) Pull out the viscometer IN-side tube (mark G) from viscometer.
[Caution] The ink in tube will slightly drip: Fit wiping paper to the end of tube. No
reverse flow of ink will occur inside the viscometer.
(E) Immediately lift the end of removed tube higher than the level of liquid in the main ink
tank, and then keep this for at least 10 seconds to return the ink in tube to the main
ink tank.
(F) When the ink has drained from tube and air enters in it, release your hand from the
tube. When air enters the tube, no reverse flow of ink will occur even if the tube hangs
down.
2 Disposing of ink inside viscometer
Remove any ink remaining inside before removing the viscometer.
(A) Turn power on.
(B) Use "Solenoid Valve/Pump Test" screen of "Maintenance menu" to turn on the pump
to MV4 in that order, and operate them for at least 10 seconds. (The ink remaining
in viscometer will return to the main ink tank.)
(C) Turn power off.
3 Unplugging connectors
[Caution] Do not perform this work with power turned on: Doing so will cause
"Viscometer Temperature Sensor Fault" to occur.
Unplug the connectors of lead wires at the back of circulation unit, and pull them
out forward through the edge saddle.
Proximity sensor: 4-pin; Thermistor: 2-pin (blue/black); Coil: 2-pin (blue/blue)
4 Removing viscometer
Remove the two setscrews from viscometer, and then pull the viscometer out
forward.
[Caution] Pay extra attention to remove O-ring. The O-ring might remain in the
circulation unit.
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