Hanna Instruments

Scientific Equipment

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HI-9934-2 Hydroponics Wall Mounted TDS Controller

HI-9934-2 Hydroponics Wall Mounted TDS Controller

HI-9934-2 Hydroponics Wall Mounted TDS Controller

HI-9934-2 Hydroponics Wall Mounted TDS Controller

Use with HI-3001D EC probe
2 year manufacturer warranty
£658.15 (exc. VAT) £789.78 (inc. VAT)

Hydroponics wall-mount Total Dissolved Solids controller with proportional setting.

HI-9934-2 Hydroponics Wall Mounted TDS Controller information

Hanna's extended description

This wall mounted meter controls TDS in the 0 to 1999 ppm (mg/L) range through a single set point 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 set point relay.

HI-9934 also provides for an alarm relay. The alarm is activated when the measurements exceed the set point by a user-selectable margin in the 50 to 450 ppm range. The alarm also goes off 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 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.

DIN connector

Water Resistant – Can withstand temporary exposure to water, but should not be submerged or washed under running water.


Specifications list


Range 0 to 1999 ppm (mg/L)
Resolution 1 ppm (mg/L)
Accuracy ±2% F.S.
Calibration manual, 2 point, with zero and slope trimmers on the front panel
Setpoint selectable from 0 to 1999 ppm (mg/L)
TDS Conversion Factor 0.65 ppm = 1 µS/cm
Temperature Compensation Automatic, 0 to 50°C (32 to 1226°F) with ß=2%/°C
Recorder Output selectable at 0-20 mA or 4-20 mA (isolated)
Proportional Control adjustable from 0 to 400 ppm, time cycle from 0 to 90 seconds
Dosing Contact 1 powered terminal for TDS correction (240 V, Max 2A, 1,000,000 strokes)
activated when reading < setpoint
Alarm Relay 1, activity when TDS exceeds the setpoint more than selectable value (50 to 450 ppm) from setpoint
or when max dosage time for pH (adjustable from 1 to 10 minutes) elapses;
(isolated, Max 2A-240 V, resistive load, 1,000,000 strokes)
Power Supply 110/115 Vac ±10% or 220/240 Vac ±10%; 50/60 Hz
Environment -10 to 50° (14 to 122°F); RH max 95% non-condensing
Dimensions 221 x 181 x 86 mm (8.7 x 7.1 x 3.4")
Weight 1.6 kg (3.5 lb.)

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