In this video, we'll be performing a multi-sensor calibration with the EXO Sonde and Kor Software. You can also use the EXO Handheld or the Kor Mobile App.
Now this is one of the coolest and most valuable features of the EXO Sondes! It allows you to save time and money by performing a single calibration on a batch or group of sensors using the same amount of calibration solution that you would use if you just calibrating one sensor. It also ensures the highest consistency across multiple sensors since you are calibrating them in the same standard solution at the same time.
This process can be performed on any EXO sensor. Here we have seven EXO Conductivity/Temperature sensors, some wiped and some non-wiped, installed on an EXO2 Sonde. If you wanted to use this feature for another sensor, you should always remember to allocate one port for a single EXO CT sensor, since all other sensors utilize temperature for their measurements. Additionally, we recommend periodically checking the temperature sensor against a NIST-traceable thermometer to ensure accuracy.
As with any calibration, it is important to make sure all of your sensors, sensor guard, and cal cup are clean. For efficiency, we suggest using a dedicated cup and guard just for calibration. Make sure to fill EXO cal cup to the second line from the bottom so that the conductivity cells are fully submerged. Now let’s immerse the sensors in the solution. Once the sensors are immersed, move the sonde around and give it a few taps to make sure there are no air bubbles trapped in the conductivity cells.
Today we are calibrating Specific Conductance in microsiemens per centimeter. Calibrating one conductivity parameter automatically calibrates all other conductivity parameters. We recommend calibrating specfic conductance, which is temperature-compensated, for both ease and accuracy. Conductivity is one-point calibration, and we suggest using a standard that is closest to your expected measurement value. Here we are using 1,000 uS/cm standard.
We’ll start in Kor by clicking on one of the CT sensors and selecting Specific Conductance to calibrate. The software detects multiple sensors present and will ask if you would like to calibrate all of them. We’ll select Yes.
Now we are in our calibration screen, and you’ll notice that it says calibration point one for sensor one of seven. Here we can also see the pre-calibration value as well as temperature. Make sure that the standard value is set correctly based on the standard solution that you are using. Kor software will indicate when your readings are stable. Once stable, we’ll click apply and the software moves on to the next sensor.
Now you’ll see the software reference sensor 2 of 7. Make sure to keep the sensors immersed in the standard solution until you finished the first calibration point. Since conductivity utilizes a 1-point calibration, we’ll be finished just as soon as we get through all of the sensors. Again, we’ll wait for readings to stabilize and click apply.
Now we are on to sensor 3 and we’ll repeat this process for all remaining sensors. Now that readings have stabilized, we’ll click apply. With readings stable, we’ll click apply. Readings are stable so we’ll click apply. And again readings are stable so we’ll click apply. Finally we are on to sensor 7. Now that readings are stable, we’ll click apply.
After you click apply for the last sensor, you’ll have the chance to review the calibration point for all of the sensors. Here you may choose to redo a sensor’s cal point or even drop a sensor from the calibration.
Everything looks good, so we’ll proceed with completing the calibration. This takes us to our calibration summary screen and we now have 7 calibrated conductivity sensors.
Be sure to check out our other EXO University videos, and thanks for watching!