Mechanical Dimensions - Hanna Instruments HI21 Series Instruction Manual

CONNECTIONS PANEL
1. 4-pin RS485 terminal (not for HI21XY1 and HI22XY1)
2. Analog output (not for HI21XY2 and HI22XY2)
3. Connections for Pt 100 temperature sensor
4. ±5V power supply output
5. Connection for Potential Matching Pin
6. Connection for electrode reference
7. Power supply input (1 Potential Earth, 2 Neutral, 3 Line)
8. Alarm terminal (1 F.S. Closed, 2 COM, 3 F.S. Open)
9. Relay 1 - first dosing terminal (not for HI21523) - (1 Normally Open, 2 COM,
3 Normally Closed)
10. Relay 2 - second dosing terminal (HI212XY models only) - (1 Normally Open,
2 COM, 3 Normally Closed)
Unplug the meter before starting any electrical connections.
FRONT VIEW BOTTOM VIEW
7