ORP Controller and Pump - BL7917-2

In stock
The BL7917 combines an ORP controller with a chemical dosing pump in order to maintain the desired set point in process applications.
  • Two advanced instruments in one compact unit.
  • Convenient installation with all controls on front panel.
  • Widely used in plating, wastewater treatment, water treatment and swimming pools.

Easy Installation

Designed with mounting holes built into a rugged base, BL7917 is simple to install. All of the controls and pump assemblies are conveniently located on the front of the unit.

Rugged Construction

BL7917 is housed in rugged, fiber-reinforced polypropylene IP55 rated casings to protect from hazardous spills and splashes. PVDF, FPM/FKM and PTFE materials are used for all parts that come into contact with liquid to resist corrosion caused by chemicals.

Simple Pump Action

A positive displacement solenoid with few moving parts makes the BL7917 more reliable than motor-driven pumps since there is no rotating parts, gears or cams; drastically reducing any chance of mechanical failure.

Proportional Dosing

A proportional control slows down the stroke rate as the measured value approaches the user selectable set points, avoiding overdosage of chemicals. This feature makes the pump’s dosing more accurate, saves chemicals and eliminates unnecessary and costly corrections to your process, especially with slow reacting chemicals.

Isolated Recorder Output

To enhance troubleshooting and the ability to record data while monitoring, simply attach a recording device to the instrument’s 4 to 20 mA output contacts, conveniently located on the front panel, to obtain a copy of the results on demand.

Auxiliary Dosing Contacts

Allows the user to attach a mixer or priming pump that is activated only when the pump is dosing.







-999 to +999 mV 


1 mV 


±5 mV 

Typical EMC Deviation 

±6 mV 


Proportional, acid or base, user selectable 


manual, 1 point through CAL (offset) trimmer   

Dosing Contact 

Isolated, 2A, Max. 240V, resistive load, 1,000,000 strokes  

Alarm Contact 

Isolated, 2A, Max. 240V, resistive load, 1,000,000 strokes 

Alarm Contact 

Terminals can be configured as normally open or normally closed (isolated output Max. 2A, Max. 240V, resistive load, 1,000,000 strokes). The alarm is activated if pH falls below the setpoint by the userselectable interval (0.0 to 2.0 pH), or conductivity exceeds the setpoint by more than the user-selectable interval (0 to 2.0 mS/cm) or due to overdosage 

Recorder Output 

4 to 20 mA (isolated) 


Any combination pH electrode with a universal BNC connector and Hanna Conductivity 4-ring potentiometric probe with built-in temperature sensor and DIN connector (optional) 

Dosing Terminals 

Two sets of independent terminals (115 to 240V, Max.2A, 1,000,000 strokes) are activated whenever pH exceeds the pH setpoint and/or conductivity falls below the EC setpoint 

Input Impedance 

10^¹² Ohm 

Power Supply 

230 Vac ±15% 50/60 Hz (40 W 


0 to 50°C (32 to 122°F); RH max 95% non-condensing 


221 x 142 x 181 mm (8.7 x 5.6 x 7.1'') 


Approximately 5 kg (11 lb.) 

Ordering information 

Each pump is supplied complete with: discharge and suction valves, LDPE tubing, 7 m (23'), power cord, and instruction manual.