Have you been struggling to get those conductivity measurements for quite some time now? It is pretty natural to make errors with these systems, especially if you aren’t quite familiar with the latest innovative sensor technology for conductivity measurements.
In many cases, you might face hurdles to test the devices due to a lack of knowledge about the technology. Start probing questions to understand the working principle properly. And to understand these concepts, you must know about conductivity sensors.
- Conductivity Sensors
Conductivity sensors are widely used in multiple sectors like chemical industries, life sciences, foods and beverages, pharmaceutical companies, water, and power. The sensors are selected wisely depending on the conductivity range and its applications. In most cases, the conductive sensors measure the low conductivities in pure and ultrapure water.
Once you understand the details about conductivity sensors and probe, it gets slightly easier to figure out the problems you have been facing in your tests. Once you have identified the conductivity probe, it is time to look for these probable mistakes for reference:
- Probe Polarization
Do you often find that the conductivity meter often shows results lower than the anticipated ones? The readings tend to get inaccurate when the charge builds on the sensors of the two electrode probe. This one commonly happens to the ones with stainless steel pins.
You can use a conductivity meter with the graphite sensors as these are quite less reactive than the former ones. Also, they use the alternating current frequencies along with the cell constant combinations.
These work best within a specific range and thereby minimize the polarization effects. And while selecting the meter, make sure that it can measure the given sample’s expected concentration.
- Fringe Field Effect
Sometimes the measurements can seem erratic if you are using a four-ring probe. It can happen due to the positioning of the probe in the beaker. Sometimes being too close to any solid object can result in something named the fringe field effects.
Here the probe generates an electrical field interrupted by any other object like the walls of the container. In case you use a metal container, it can create a positive interference resulting in producing higher results. It is slightly different for glass or plastic containers. Here, the reading is too low.
And to fix this issue, you need to place the conductivity probe appropriately and not too close or away from the container. Try to put it at least an inch away from all the sides of your container to avoid such errors.
- Improper Probe Calibration
The conductivity calibration solutions do not come with buffering capacity. Therefore the sample that remains on your probe can change its values. And to get accurate calibration results, you need to make sure that the sample isn’t contaminated.
To avoid such hassles, why not prime the probe with the calibration solution? Get ready to dip the clean conductivity probe within a rinse solution and go ahead with a fresh solution.
- Incorrect TDS Conversion Factor
Total dissolved solids or TDS is directly related to conductivity. With the increase in dissolved ions like potassium and calcium, the conductivity rate also increases. When you use the conductivity meter to measure TDS, you need a special conversion factor to get the readings.
Although using these factors is pretty easy, you might sometimes face errors due to such calculations. Therefore, make sure to choose the conversion factor wisely not to face any troubles accurately read after each measurement.
You can also try understanding the details about the conductivity probe and thereby identify your errors with time. In case of doubts, do not shy away from seeking guidance from the industry’s best professionals.