The CMA Conductivity sensor W04 can be used to measure the conductivity of a solution within the range of 0 to 20 mS/cm. It is suitable for measuring salinity and changes in the conductivity of a water sample. Although it will not identify the specific ions that are present, it can be used to determine the total concentration of ions in a sample.

The conductivity sensor is equipped with an OLED colour display which shows sensor information and the measured values. This makes the sensor suitable to use as an independent measuring instrument.

The wireless conductivity sensor can be used wirelessly via Bluetooth or wired via USB with the Coach or Coach Lite programs/apps on computers (Windows and Mac), Chromebooks and mobile devices (Android and iOS).

Technical Specifications

• Measuring range: 0 to 20 mS/cm
• Resolution: 0.01 mS/cm
• Accuracy: ±1% of full-scale reading
• Warrantee: 24 months
• Response tim: 98% of full-scale reading in 5 s, 100% in 15 s
• Temperature correction: Automatic between 5°C and 35°C
• Temperature range: between 0°C and 80°C
• Maximal sampling rate: 100 Hz
• Battery life: 4h when full (rechargeable)
• Connection: Bluetooth 5, Low Energy (Mac, Android, iOS) Bluetooth 2.1, Classic (Windows) or USB-C 2.0

All specifications of the sensor are described it its User guide.

Suggested Experiments

• Confirmation of the direct relation between conductivity and ion concentration in aqueous solutions. Concentration of unknown samples can be determined.
• Measurement of changes in conductivity resulting from photosynthesis in aquatic plants, with the resulting decrease in bicarbonate-ion concentration due to the carbon dioxide consumption.
• Monitoring the rate of reaction in a chemical reaction in which dissolved ions and solution conductivity varies with time due to ionic species being consumed or produced.
• Performing a conductivity titration to determine when stoichiometric quantities of two substances have been combined.
• Finding the rate at which ionic species diffuse through a membrane such as dialysis tubing.
• Monitoring changes in conductivity or total dissolved solids in an aquarium containing aquatic plants and animals. These changes could be due to photosynthesis or respiration.