HI 9934: TDS Controller with Proportional Function, Wall Mount

• Ideal for Hydroponics & Fertigation
• Single setpoint for dosage of fertilizers
• User selectable isolated output

This wall mounted meter controls TDS in the 0 to 1999 ppm (mg/L) range through a single setpoint for dosage of fertilizers. The proportional control can be fine tuned through the time cycle between 0 to 90 seconds and the proportional band from 0 to 400 ppm. Coarse and fine as well as a slope trimmer make for an accurate setting and calibration. A pump or electro-valve can be powered through the terminal. In addition to the setpoint relay, HI 9934 also provides for an alarm relay. The alarm is activated when the measurements exceed the setpoint by a user-selectable margin in the 50 to 450 ppm range. The alarm also goes off if due to a malfunction, the continuous dosing time exceeds the operator adjustable period of 1 to 10 minutes. The alarm can be configured in either normally-closed or normally open position and turned off during maintenance. HI 9934 also provides an isolated output signal which is user selectable between 0-20 or 4-20 mA. HANNA instruments® 4-ring TDS probes with incorporated temperature sensor and DIN connector can be quickly attached to the controller. Readings are automatically compensated for temperature variations in the 0 to 50°C (32 to 122°F) range. The extractable terminal wiring is through the side of the meter with washers and grommets. The compartment containing the connections is closed behind a fire-retardant ABS panel.

HI 9934 is supplied complete with instructions.