Hach 911, User Manual

Page: 59 / 103

57
Section 7 Maintenance
DANGER
Only qualified personnel should conduct the tasks described in this section of the
manual.
DANGER
Seul un technicien qualifié peut effectuer les tâches d'installation décrites dans
cette section du manuel.
DANGER
All maintenance activities related to flow meter and flow meter accessories must be
performed in a non-hazardous location.
DANGER
Toutes les opérations de maintenance relatives au débitmètre et à ses accessoires
doivent être exécutées dans un environnement qui ne présente aucun danger.
7.1 Maintaining the Battery Compartment Desiccant
The desiccant material is a silica gel indicator. When the gel is saturated with moisture, the
beads turn from blue to pink. To rejuvenate the beads for reuse, remove them from the
assembly. Heat the beads in an oven at 100 to 180 °C (212 to 350 °F) until the beads turn
blue again. Discard and replace the beads if they do not turn blue after heating.
7.1.1 Replacing the Battery Compartment Desiccant
A small desiccant cartridge in the battery compartment ( Figure 17 on page 32 and
Figure 18 on page 32 ) prevents moisture damage to the batteries and power circuitry.
Table 9 contains replacement part numbers.
If the normally blue desiccant beads turn pink, replace the cartridge or remove the
cartridge end cap and recharge or replace the desiccant material.
A small clip holds the desiccant cartridge in place. Pull the cartridge straight out of the clip
to remove it.
7.2 Maintaining the O-Ring Gasket on the End Cap
Note: Do not use petroleum jelly to lubricate the O-rings.
Two O-ring gaskets are installed in each flow meter end cap. The end caps maintain the
water tight seal on the flow meter. Use care when the end caps are removed—do not soil,
cut, or nick the gaskets. Replace them immediately if any physical damage is apparent.
Use a light coating of O-ring lubricant to help maintain a water-tight seal.
Table 10 on page
57 lists replacement O-ring gaskets.
Table 9 Replacement Desiccant
Description Part Number
Model 911 Battery Compartment Desiccant Cartridge 4933
Model 940 Battery Compartment Desiccant Cartridge 4967
Bulk Desiccant Refill (1.5 lb.) 3624
Table 10 Replacement O-rings
Description Part Number
Model 911 End Cap O-ring (2 required) 4912
Model 940 End Cap O-ring (2 required) 4807