ELGA PURELAB UHQ II, Руководство по обслуживанию

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ELGA PURELAB UHQ II & PS Service Manual
PURELAB UHQ II & PS Service issue 2 03/07 18
9. CALIBRATION
WARNING! GREAT CARE MUST BE TAKEN AT ALL TIMES DURING
THIS CALIBRATION PROCEDURE, AS EXPOSED MAINS
VOLTAGES ARE PRESENT WITHIN THE CABINET
9.1 Line Cell calibration
9.1.1 Remove right-hand and left-hand side covers from the unit.
9.1.2 Remove the four fixing screws holding the front cover to the framework. These
are accessible at the back corners of the front cover, having first removed the
two side covers.
9.1.3 Remove the retaining plug from underneath the Dispense Pen well; this is
situated underneath the front right-hand edge of the unit and is a grey-coloured
plug which is simply pulled from the tube it is pressed into.
9.1.4 Whilst standing at the front of the unit, rotate the front panel, about its left hand
vertical edge to expose the electronics compartment. Care should be taken to
ensure no strain is applied to the ribbon cables connecting the main control
PCB to the display PCB.
9.1.5 Disconnect line-cell from power supply PCB (see Fig 9.1 on next page).
9.1.6 Connect unit mains cable to suitable power supply, ensuring green power LED
is illuminated on fascia panel.
9.1.7 Connect the SUB04 setting box to the line cell socket on the PCB. Set SUB04
box to position 2 and adjust the left-hand pot (P4) on the main PCB for an
indicated 2 bars on the 'Quality' display.
9.1.8 Position setting box knob to 18. Adjust right-hand pot (P5) on main PCB to
indicate 18 M
Ω
.cm on the 'Quality' display.
9.1.9 Repeat instructions 9.8 and 9.9, and readjust until a satisfactory setting is
obtained.
9.1.10 Check that at each SUB04 box setting, the number of bars displayed,
correspond to the M
Ω
.cm scale with the exception of the initial setting. At this
setting, 1 bar should be displayed.
9.1.11 Disconnect SUB04 setting box from power supply PCB and reconnect line-cell.
9.1.12 Refit front and side covers to the unit.
Note: The foregoing calibration has checked that the 'Quality' circuits of the
power supply and display PCB's are functioning correctly.
With the line-cell reconnected, a simple check can be made on the basic function of the
of the line-cell. This is carried out by removing the probe from its housing; with the
probe removed, the display should read 18 M
Ω
.cm. If the pins are then short circuited,
place a steel rod or small electrical screwdriver across the pins, the display should then
read 0 (zero), i.e. 1 bar displayed. Refit line-cell probe into housing.
!