Alpha TDS 200 Total Dissolved Solids Controller/Transmitter

  • Advanced Security Two levels of password security to guard from unauthorised tampering
  • Warranty This product is covered by a 1 year warranty
  • Selectable Temperture Coefficient Ensures higher TDS accuracy
Product Options


Measuring from pure water to electroplating rinse tank water is a simple process using the Eutech Alpha TDS 200. RS Hydro are proud distributors of this straightforward and reliable controller/transmitter which measures up to ±1% full scale accuracy across eight conductivity/TDS ranges. Enhanced TDS accuracy is delivered by using the selectable temperature coefficient while the user has the option of choosing either automatic or manual temperature compensation and three wire system compensates error due to cable resistance.

Calibration is simple push button process and handily the controller freezes data transmission and relay activities during calibration and maintenance. For heightened security the Alpha TDS 200 has two levels of password security which protects calibration and meter settings from unauthorised tampering.

Additional features which aid the Alpha TDS 200 to be a flexible device are the full scale 4 to 20 mA galvanically isolated current output for process control and the 85 to 250VAC. 50/60 Hz or DC variable input enables the Alpha TDS 200 to be used in a wide range of supply voltages.

Manufactured by: Eutech Instruments
Model: Alpha TDS 200 Total Dissolved Solids Controller/Transmitter

Services offered for this product

  • Sales
  • Rental
  • Installation
  • Calibration
  • Maintenance


TDS 200
Ideal for drinking water, monitoring and control, and hydroponics and aquaponic solution balance and control, pools and spa hardness and salinity control.


Range ... to 10.00 ppm ; ... to 100.0 ppm ;
... to 1000 ppm ; ... to 5.00 ppt ;
... to 10.00 ppt ; ... to 100.0 ppt
Resolution 0.01 ppm ; 0.1 ppm ;
1 ppm ; 0.01 ppt ;
0.1 ppt
Cell Constant 0.1 ; 1 ; 10
Relative Accuracy ±1 % of full scale
Range -10 to 110 °C
Resolution 0.1 °C
Accuracy ±0.5 °C
Sensor Pt100; 2 or 3 wire
Compensation Auto/manual (0 to 50 °C)
Coefficient 0.0 to 5.0 %
Normalisation 10.0 °C to 30.0 °C
Factor 0.40 to 1.0
Set Point And Controller Functions
Set Point 1 (SP1)/
Set Point 2 (SP2)
... to 10.00 ppm or ... to 100.0 ppm or
... to 1000 ppm or ... to 5.00 ppt or
... to 10.00 ppt or ... to 100.0 ppt
Switching Conductivity Hysteresis 0 to 10 % of full scale
Switching TDS Hysteresis 0 to 10 % of full scale
Function Limit control
Contact Outputs 2 SPDT relays
Switching Voltage/
Max. 250 VAC / max. 3 A / max. 600 VA
Electrical Data and Connections
Transmitter Function 4 to 20 mA scalable outputs for Conductivity, galvanically isolated
Load 200 Ohm
Conductivity/TDS Input 2-pin terminal
Connection Terminal 3-pin, 7-pin & 9-pin terminal, detachable blocks, 1 fixed connector
LED 7 segments display
Power Supply
Input 85 to 250 VAC, 50/60 Hz
Main Fuse 250 mA, anti-surge, S504 Bussman
Rated Input Current (Max.) 100 mA
Insulation Category II
EMC Specifications
Emitted Interference According to EN 61326
Immunity To Interference According to EN 61326
Environmental Conditions
Operating Temperature Range -10 to 50 °C
Max. Relative Humidity 10 to 95 % (non-condensing)
Mechanical Specifications
Dimensions (WxHxD) 96 x 48 x 150 mm
Weight 300 g (unit) / 350 g (packed)
Ingress Protection IP50



TDS is only relevant in freshwater systems as salinity will dramatically increase the conductivity and therefore apparent TDS.
TSS are particles that are larger than 2 microns found in the water column. Anything smaller than this is called a dissolved solid.