alpha TDS190 with improved user interface enables user to gain direct access to calibration mode with CAL key and allows quick set point adjustment with SP1 and SP2 keys. Product Features :: Quick Set Point Adjustment - SP1 and SP2 keys allow user to adjust set points easily :: Direct Access to CAL Mode - enables user to enter calibration mode with a simple key press :: User-Customisation with scrolling, 14-Segment LED - intuitive user interface guides user easily through setup functions :: Multi Measurement Range- User Selectable :: Galvanically Isolated 4-20 mA Output for remote monitoring or hardcopy recording :: Universal Power Supply Input from 85 to 250 VAC/DC allows use at multiple sites and withstands voltage fluctuations :: Automatic Temperature Compensation with 3-wire Pt 100 system ensures accurate readings under fluctuating temperatures :: Adjustable Temperature Coefficient (0 to 5.0%/oC) and selectable cell constants for more accurate measurements :: Adjustable Hysteresis (Dead Band) prevents rapid contact switching near set point :: Non-Volatile Memory retains all stored parameters and calibration data even if power fails :: Easy Installation and Wiring with detachable plug-in connectors Applications TDS 190: Ideal for drinking water, monitoring and control, hydroponics and aquaponic solution balance and control, pools and spa hardness and salinity control. Specifications Product Specification Description Conductivity Range 0.00 – 10.00 ppm 0.0 – 100.0 ppm 0.0 – 100.0 ppm 0 – 1000 ppm 0.00 – 5.00 ppt 0.00 – 10.00 ppt 0.0 to 100.0 ppt 0.0 – 200.0 ppt 0.01 ppm 0.1 ppm 0.1 ppm 1 ppm 0.01 ppt 0.01 ppt 0.1 ppt 0.1 ppt Accuracy ± 1% of full scale Temperature Range -10 to 110 °C Resolution & Relative Accuracy 0.1 °C & ±0.5 °C Temperature Sensor Pt 100 (3-wire) Temperature Compensation Auto / Manual (0°C to 100°C) Temperature Coefficient 0.0 to 5.0 % Normalisation Temperature 10.0 to 30.0 °C Set Point and Controller Functions Function Limit Control Switching Hysteresis 0 to 10% of full scale Contact Outputs, Controller 2 SPDT relays Switching Voltage/ Current/ Power Max 250 VAC/ Max 3A/ Max 600 VA Electrical Data and Connections Power Requirement 85 to 260 VAC, 50/60 Hz or DC Signal Output/ Load 4-20mA galvanically isolated / 200Ω Connection Terminals 3 detachable connectors (3-pin; 7-pin & 9-pin terminal blocks) + 1 fixed connector Main Fuse 250mA, Anti-surge (BUSSMAN S504 + 250mA) Environmental Conditions Maximum Relative Humidity 10 to 95% (Non-condensing) Ambient Temp. Operating Range -10 to 50 °C Mechanical Specifications Dimensions 96 x 48 x 150 mm Weights 300 g (boxed)