Fail Safe Alarm System
Hanna’s exclusive Fail Safe Alarm System protects against problems caused by power supply failure or signal interruption, which are typical risks in industrial environments. An alarm condition is indicated by a red LED, located directly on the front panel of the controller.
Overtime Dosing Protection
The HI8711 incorporates adjustable overtime dosing protection from 5 to 60 minutes. If dosing exceeds selected time, the alarm will be triggered and the dosing contact will deactivate. This feature can be activated or deactivated.
Output and Input Connections
Each model accepts either a direct input from a pH or ORP electrode or from a transmitter through 4-20 mA input. The instrument also provides ±5V power output and input terminals for amplified electrodes. Moreover, you can choose the output configuration for connecting a recorder or a PLC, between 0-20 or 4-20 mA.
Self-Diagnostic Test
Built-in autodiagnostic functions enable the user to check and troubleshoot any malfunctions. The functions are made via front panel keys to isolate the cause of malfunction whether it is due to pH electrode contamination, internal offset circuit or the amplifier circuit.
Matching Pin Connection
Supports potential matching pin connection to avoid typical problems caused by grounding loop currents, such as progressive damage of the electrode, fluctuating measurements, and poor process regulation.
Robust Design
A removable, transparent splash-proof cover protects the front panel.
| Specification Name | Detail |
|---|---|
| sku | HI8711 |
| pH Range | 0.00 to 14.00 pH |
| pH Resolution | 0.01 pH |
| pH Accuracy (@20°C/68°F) | ±0.02 pH (0 to 100 °C)/ ±0.05 pH (-20 to 0 °C) (electrode); ±0.5% (transmitter) |
| Temperature Compensation | Fixed or automatic with Pt100 from -20 to 100 °C (-4 to 212 °F) |
| Calibration | Offset: ±2 pH with OFFSET trimmer; Slope: 80 to 110% with SLOPE trimmer |
| Recorder Output | 0-20 mA or 4-20 mA (isolated) |
| Analog Input | 4 to 20 mA |
| Power Output | ±5 Vcc; 150 mA max load for amplified electrodes |
| Setpoint Relay | 2, isolated, 2 A, Max 240 V, resistive load, 1000000 strokes (not fuse protected) |
| Setpoint Range | 0.00 to 14.00 pH |
| Backlight | Continuous ON |
| Dosing Control | OFF/AUTO/ON with selection switch |
| Over Dosing Control | Adjustable, from 5 min to 60 min with knob or Disable by wire strap – on rear panel |
| Power Supply | 115 or 230 Vac; 60/50 Hz |
| Alarm Relay | 1, isolated, 2 A, Max 240 V, resistive load, 1000000 strokes (not fuse protected) |
| Alarm Range | 0.2 to 3.00 pH |
| Environment | $-10 to 50°C (14 to 122°F); RH max 95% non-condensing |
| Enclosure/ Case Material | Black anodized aluminium body; front and back with ABS; transparent splash-proof front cover |
| Dimensions | 141 x 69 mm (5.6 x 2.7”) |
| Weight | kg (2.2 lb.) |
