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Milwaukee EC59 PRO Waterproof 3-in-1 Conductivity / TDS & Temperature Tester with Replaceable Probe

SKU: 9139-EC59~ea

SKU: 9139-EC59~ea

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Milwaukee EC59 PRO Waterproof 3-in-1 Conductivity/TDS & Temperature Tester with Replaceable Probe

The Milwaukee EC59 PRO Conductivity (EC) & Total Dissolved Solids (TDS) Tester is designed for aquaculture, food, wine, laboratory, water treatment and many other applications. It is the ideal meter to help make sure that your EC/TDS/Temp. needs are being met and offers reliable results for your analysis.


  • Measures EC/TDS/Temp. with automatic temperature compensation (ATC)
  • Ideal range for all different applications (0 to 3999 uS/cm) | 0 to 2000 ppm | 0.0 to 60°C (32.0 to 140.0°F)
  • Units in uS/cm or ppm easily convertible to other ranges
  • Factory calibrated with the ability to recalibrate if needed
  • Replaceable electrode Mi59P
  • Fully waterproof to IP65
  • Approximately 100 hours of use (4 x 1.5V batteries included)



  • pH Range: -2.0 to 16.0 pH
  • ORP Range: ±1000 mV
  • Temperature Range: -5.0 to 60.0°C (23 to 140°F)
  • pH Resolution: 0.01 pH
  • ORP Resolution: 1 mV
  • Temperature Resolution: 0.1°C (0.1°F)
  • pH Accuracy: ±0.05 pH @25°C (77°F)
  • ORP Accuracy: ±1 mV
  • Temperature Accuracy: ±0.5°C (±1°F)
  • Typical EMC Deviation: ±0.02
  • Typical EMC Deviation: ±2 mV
  • Typical EMC Temperature Deviation: ±0.3°C (±0.6°F)
  • Temperature Compensation: Automatic from -5 to 60°C (23 to 140°F)
  • Calibration Automatic: 1 or 2 points with 2 sets of pre-memorized buffers (pH 4.01, 7.01, 10.01) or (pH 4.01, 6.86, 9.18)
  • Probe: Replaceable double junction for extended life (Mi58P)
  • Environment: -5 to 50°C / 23 to 122°F; max RH 100%
  • Battery Type: 4 x 1.5V; IEC LR44, A76 (included)
  • Battery Life: Approx. 250 hours of use
  • Auto-off: after 8 minutes on non-use
  • Dimensions: 7.9 inches × 1.5 inches (diameter)
  • Weight: 3.5 ounces (99.22 g)

Milwaukee EC59 Manual



EC electrodes can develop nutrient build up over time. To minimize build up, always rinse the probe in fresh tap water after every use.


The Milwaukee PRO Conductivity Tester, like all conductivity meters, provides a measure of electrically charged ions in a solution and is an absolute measure of conductivity.

EC/TDS can be converted. Different scales include the 500 scale, 650 scale and the 700 scale. 

Your uS/cm reading can be approximately converted to other scales as shown in the examples below.

2.00 mS/cm = 2000 uS/cm = 1000 ppm on .50 factor scale

2.00 mS/cm = 2000 uS/cm = 1400 ppm on the 442 scale or .70 factor scale