Hach 911, User Manual

Page: 61 / 103

59
Maintenance
7.7 Replacing the Batteries in the RS232 Interface
DANGER
Never replace batteries in a hazardous location.
DANGER
Ne jamais remplacer les piles dans une zone dangereuse.
The Opto-Isolated RS232 interface uses a quantity of industrial quality Alkaline “C” cells.
Under normal circumstances the batteries should last for more than 1,000 downloads
based on an average download time of 5 minutes. The batteries need to be changed once
a year due to the limited shelf life of any type of battery.
1. Remove the cover from the RS232 interface ( Figure 32 ).
2. Remove the old batteries. Install fresh batteries into the RS232 interface, making
certain the polarity is correct.
7.8 Maintaining the
Submerged Area/Velocity
Sensor
7.8.1 Cleaning the Transducer Port
Clean the transducer port when:
• A drift in the readings is observed.
• Level data are missing or incorrect but velocity data are valid.
• Excessive silt has deposited between the transducer and its protective cover.
Figure 32 Replacing RS232 Batteries