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DTK Water

SD40 Multi

The SD40 Multi Pocket Tester is a versatile, all-in-one solution for measuring multiple water quality parameters in the field. Combining pH, conductivity, salinity and TDS measurement in one compact instrument, it provides a convenient and reliable way to carry out comprehensive water testing across a wide range of applications.

Designed for professional users who require flexibility and accuracy, the SD40 is ideal for routine monitoring in industrial water systems, swimming pools, water treatment and other applications where multiple parameters need to be measured quickly and efficiently.


With its robust IP67 waterproof housing, the SD40 is built for dependable operation in demanding environments. The transparent protective lid provides protection during storage and transport while also acting as a stable stand during measurement and allowing easier access for electrode maintenance.


The intuitive three-colour backlit LCD display provides clear visual feedback, with blue indicating measurement mode, green indicating calibration mode and red highlighting alarm conditions. Combined with automatic temperature compensation, multiple calibration options and simple controls, the SD40 provides accurate results with minimal effort.


Powered by 4 x AAA batteries and energy-efficient LED technology, the SD40 delivers over 2000 hours of battery life. Its compact design, integrated clip and included lanyard make it easy to carry and use wherever testing is required.

Key Features

  • Multi-parameter measurement of pH, conductivity, salinity and TDS
  • Waterproof IP67 housing for reliable field use
  • Compact and portable design
  • Transparent lid for protection, maintenance and stable positioning
  • Three-colour backlit LCD display:
    • Blue: Measurement mode
    • Green: Calibration mode
    • Red: Alarm indication
  • Automatic temperature compensation
  • Automatic buffer recognition
  • Auto-hold and stability indicator functions
  • Alarm limit settings
  • Multiple calibration options
  • Over 2000 hours battery life
  • CE compliant

Applications

  • Boiler Water
  • Cooling Water
  • Drinking Water Treatment
  • Pool Water Control
  • Wastewater Treatment

Technical Data

  • Measurement Parameters:
    • Conductivity: 0.01 – 20.00 mS/cm
    • pH: 0 – 14
    • Salinity: 0.01 – 10 g/L
    • TDS: 0.01 – 20.00 ppt
  • Accuracy:
    • pH: ±0.01 (±1 digit)
    • pH (mV): ±0.2% FS
    • Conductivity / TDS / Salinity: ±1% FS
    • Temperature: ±0.5 °C
  • Resolution:
    • pH: 0.01
    • Conductivity: Auto scale 0.1 µS/cm, 1 µS/cm, 0.01 mS/cm
    • TDS: Auto scale 0.1 ppm, 1 ppm, 0.01 ppt
    • Salinity: 0.01 ppt
    • Temperature: 0.1 °C
  • Calibration:
    • 1–3 calibration points
    • Automatic mode:
      • Conductivity standards: 1413 µS/cm or 12.88 mS/cm
    • Manual mode adjustment: ±50%
  • Buffer Auto Recognition:
    • pH:
      • USA: 1.68 / 4.00 / 7.00 / 10.01 / 12.45 pH
      • NIST: 1.68 / 4.01 / 6.86 / 9.81 / 12.45 pH
    • Conductivity:
      • 84 µS/cm / 1413 µS/cm / 12 mS/cm
  • Temperature Compensation: Automatic
  • Calibration Indicator: Yes
  • Stability Indicator: Yes
  • Auto-Hold Function: Yes
  • Alarm Limits: Yes
  • Display: 3-colour backlit LCD
  • Auto-Off: Yes
  • Power Supply: 4 x AAA batteries
  • Battery Life: >2000 hours
  • Operating Conditions: 0 – 60 °C / 0 – 80% relative humidity (non-condensing)
  • IP Rating: IP67
  • Compliance: CE
  • Dimensions: 40 x 40 x 180 mm
  • Weight: 151 g

   Order Code   Description 
720040SD40 Multi Pocket Tester
 720045SD40 Multi Replacement Electrode 

SD Series Leaflet