1. BNC plug for pH electrode
2. Connection for electrode reference
3. Connection for potential Matching Pin
4. Acid/Alkaline dosage selection terminal:
• contact open = acid selection
• contact closed = alkaline selection
5. 4-20 mA output terminal for recorder connection
6. Power supply terminal:
• for BL931700-0 model: 12 Vdc adapter
• for BL931700-1 model: 115 Vac or 230 Vac option
7. This contact acts as a switch for driving the dosing system (e.g.
dosing pump)
8. External control and disabling of dosing system
9. Jumper for enabling (jumper in) or disabling (jumper
removed) the overtime control
10. Trimmer for overtime setting (typically from 5 to 30 minutes)