Hach-Lange CL17 USER MANUAL - Manual (Page 41)

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Section 6 Maintenance
DANGER
Multiple hazards. Only qualified personnel should conduct the tasks described in
this section of the manual.
CAUTION
Chemical exposure hazard. To familiarize yourself with handling precautions,
dangers and emergency procedures, always review the Material Safety Data Sheets
prior to handling containers, reservoirs, and delivery systems that contain
chemical reagents and standards. Protective eye wear is always recommended
when contact with chemicals is possible.
6.1 Scheduled maintenance
6.1.1 Replenish the reagents
One 500-mL bottle each of buffer and indicator solution lasts approximately one month.
Discard the old containers with any unused contents and install the new bottles as
described in
section 4.1 on page 27 .
6.1.2 Replace the pump tubing
Over a period of time, the clamping action of the pump/valve module will soften the tubing
and cause it to collapse and obstruct liquid flow. This breakdown is accelerated at high
temperatures. The following replacement schedules, based on ambient operating
temperature, are recommended:
• Below 27 °C (80 °F), replace at six-month intervals.
• Above 27 °C, replace at three-month intervals.
Pump tube replacement procedure:
1. Shut off sample flow to the instrument and set the POWER (I/O) switch to OFF (O).
2. Remove the screws securing the pinch plate to the pump/valve module. Refer to
section 3.9 on page 24 . Loosen in small increments, moving from one screw to the
other to allow tension to be relieved evenly. Remove the plate.
3. Disconnect the pump tubes from the inlet and outlet fittings and discard the tube
assemblies.
4. Cut four 2-inch lengths of 1/16-inch ID tubing (white). Install one 1/16-to 1/8-barb
elbow fittings in one of the 1/16-inch ID tubes (white) and 1/16-inch barb union fittings
in the three remaining tubes. Although one of the pump tubes is not used for fluid
flow, it must be included to provide even compression on all four tubes.
5. Install the two screws through the pinch plate and into the pump/valve module. When
securing the pinch plate, advance the screws in small increments moving from one
screw to the other so that the plate is drawn down evenly. Tighten until snug, do not
overtighten.
6. Set the POWER (I/O) switch to ON (I) and restore sample flow through the
instrument. Allow the instrument to run for approximately one hour to fill the reagent
lines.