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DTK Water

SD20 ORP

The SD20 ORP Pocket Tester provides a reliable and convenient solution for measuring oxidation-reduction potential (ORP) in the field. Designed for fast and accurate testing, it offers a practical way to monitor water quality in applications such as industrial water systems, swimming pools, water treatment and other routine monitoring environments.

With its robust IP67 waterproof housing, the SD20 is designed for dependable use in demanding conditions. Its compact and portable design allows users to carry out ORP measurements wherever testing is required, while the intuitive interface ensures simple operation with minimal training.


The transparent protective lid provides protection during storage and transport while also acting as a stable stand during measurement. It also improves access for electrode maintenance, helping maintain long-term performance and reliability of the tester.


The SD20 features a three-colour backlit LCD display, providing clear visual feedback during operation. Blue indicates measurement mode, green indicates calibration mode and red highlights alarm conditions, making it easy for users to understand the status of the instrument at a glance.


Powered by 4 x AAA batteries and using energy-efficient LED technology, the SD20 provides over 2000 hours of operating life. The included lanyard and integrated clip allow the tester to be comfortably carried around the neck, attached to a pocket, waistband or belt for convenient on-site testing.

Key Features

  • Accurate ORP measurement from -1000 to 1000 mV
  • 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
  • One-point calibration with adjustable ORP value
  • Auto-hold and stability indicator functions
  • Alarm limit settings
  • Over 2000 hours battery life
  • CE compliant

Applications

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

Technical Data

  • Measurement Parameters:
    • ORP: -1000 – 1000 mV
    • Temperature: 0 – 50 °C
  • Accuracy:
    • ORP: ±0.2% FS
    • Temperature: ±0.5 °C
  • Resolution:
    • ORP: 1 mV
    • Temperature: 0.1 °C
  • Calibration:
    • 1 point calibration
    • Adjustable ORP calibration value ±150 mV
    • Buffer Recognition: +470 mV (25 °C), Pt | Ag/AgCl (3 M KCl)
  • Temperature Compensation: Automatic
  • Stability Indicator: Yes
  • Auto-Hold Function: Yes
  • Alarm Limits: Yes
  • Display: 3-colour backlit LCD
  • Auto-Off: No
  • 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 
720020SD20 ORP Pocket Tester
 720025SD20 ORP Replacement Electrode 

SD Series Leaflet