In this video, we'll be calibrating the EXO Turbidity sensor in FNU using Kor Software. You can also use the EXO Handheld or the Kor Mobile App.
Before calibrating, it is important to make sure that your sensors, sensor guard, and cal cup are all clean. If you have a wiper installed, make sure that the wiper brush and brush guard are also clean. For best practices, we suggest using a dedicated cup and guard just for calibration.
It is possible to perform a 1-, 2-, or 3-point calibration. While a 3-point cal using 1000 standard improves performance at that range, we’ll be performing a 2-point calibration, as this is sufficient for most applications. If you are using an EXO cal cup, make sure to fill to the first line from the bottom to ensure the sensor tip is fully submerged. It is important to take care when pouring to not introduce air bubbles into the solution as they could skew the calibration.
Now let’s immerse the sensor in the calibration solution. For turbidity calibrations, we always start with a zero standard. Here we are using YSI’s zero FNU standard. Once immersed, it is extremely important to make sure the sensor lens is free of any air bubbles that could skew the reading. You can do a visual inspection, or if you have a clean wiper installed, you can activate the wiping mechanism to clear the lens.
Kor software will indicate when your readings are stable, and you can see the turbidity values in real time. Once the readings are stable, we’ll apply the first calibration point. You will then see the calibration summary, and you can double-check the calibration values. From here, you have the opportunity to redo the calibration point, complete, or proceed with the next point. We’ll rinse and dry our sensor and move on to the next point.
We recommend using YSI’s 124 FNU polymer standard for Cal Point 2. The polymer standard does not need to be shaken since it does not settle, unlike other turbidity calibration standards. Again, we’ll immerse the sensors in the solution and make sure there are no air bubbles on the lens. After stabilization, we’ll apply the second cal point. Here again, we can see the calibration summary, and this time we’ll complete the calibration.
Now our turbidity sensor is calibrated and ready for use. Be sure to check out our other EXO University videos, and thanks for watching!