In a recent LinkedIn poll we conducted, the majority of voters reported struggling with inconsistent conductivity readings. This frustration is all too common and can significantly impact the accuracy of your experiments.
Today, let’s examine some common culprits behind these fluctuations, equipping you with the knowledge to tame them for good.
The four most important ones are discussed below.
2.???? Annoying Air bubbles
3.???? Correct Calibration
- Probe Problems Ensuring complete immersion of the conductivity probe is the basic checkpoint and essential in obtaining accurate conductivity measurements. One must check the operating instructions for the minimum immersion depth of the sensor to understand how much one should submerge it. Salt deposition can build up a coating on the electrodes of the conductivity cells, leading to contamination issues and erroneous readings. Correct cleaning procedures can help reduce these errors. Inspecting the sensor frequently for signs of wear and tear can avoid errors due to poor health of sensor.
- Annoying Air bubbles These uninvited guests increase the resistance and decrease the conductivity of the sample, so removing them before immersing the sensor is necessary for stable readings. The easiest way to remove them is to tap the sensor or lower and raise the sensor in the sample beaker. Rinsing between measurements is the key to avoiding contamination from previous samples. Develop a consistent routine using deionized water – it'll become second nature in no time.
- Correct Calibration Regularly calibrating the sensor with standard solutions is crucial. Think of it as giving your sensor a course correction on the right conductivity. For a correct sensor calibration, it is advised to follow the manufacturer's instructions. Also avoid the temptation to use expired or contaminated solutions, as this will lead to inaccurate readings. Refer to the cleaning instructions in the manual if washing with deionized water doesn’t suffice.
- Temperature Trap Conductivity measurements are temperature-dependent. A change in sample viscosity with a change in sample temperature leads to an increase or decrease in the mobility of ions, which, in turn, changes the conductivity value. Therefore, it is important to accurately note the measurement temperature for applying temperature correction. If you’re using meters with automatic temperature correction, the battle is half-won!
Following these good measuring practices and adopting a meticulous maintenance routine can achieve consistent and reliable conductivity readings. If you liked reading this and would like to learn more, our conductivity theory guide is available for download here. Also, our team of technical experts is always happy to support you and can be reached at [email protected].
