Replace The Desiccant; Pump Maintenance - Hach SD900 Manual Básico Del Usuario

• Sample bottles—Clean the bottles with a brush and water and a mild detergent. Rinse with fresh
water and then with distilled water. Use an autoclave to clean glass bottles if necessary.

Replace the desiccant

A desiccant cartridge in the controller absorbs moisture and prevents corrosion. Monitor the
desiccant color through the window
replace the desiccant.
1. Unscrew and remove the desiccant cartridge
2. Remove the plug and discard the spent desiccant.
3. Fill the desiccant tube with fresh desiccant.
4. Install the plug.
5. Apply grease to the O-ring.
6. Install the desiccant tube in the controller.
Figure 12 Desiccant cartridge
1 Plug
2 Desiccant tube

Pump maintenance

Pinch hazard. Remove power from the instrument before maintenance or service activities are done.
Replace the pump tubing
Use of tubing other than that supplied by the manufacturer can cause excessive wear on mechanical parts and/or
poor pump performance.
Examine the pump tubing for wear where the rollers rub against the tubing. Replace the tubing when
the reminder message is shown or when the tubing shows signs of wear.
Pre-requisites:
• Pump tubing—pre-cut or bulk 4.6 m or 15.2 m (15 ft or 50 ft)
1. Disconnect the power to the controller.
2. If the bulk tubing is used, cut the tubing and add alignment dots. Refer to the expanded manual
on the manufacturer's website.
3. Remove the pump tubing as shown in the illustrated steps that follow.
4. Clean the silicone residue from the interior of the pump housing and from the rollers.
5. Install the new pump tubing as shown in the illustrated steps that follow.
24 English
(Figure 12). Fresh desiccant is yellow. When the color is green,
(Figure 12).
3 O-ring
4 Desiccant window
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