Every month (weekly recommended) you should check the EC calibration. Clean the face of the probe. Remove the shroud from the end of the probe and use a little kitchen liquid scouring cleaner such as “Jif" or "SoftScrub” on a clean “Scotchbrite” nylon scouring pad. Alternatively, use 600 grit wet-and-dry paper with the cleanser. Use a circular motion to scour the face of the probe and then rinse well in running water. Do not touch the face of the probe but shake off any residual water. Replace the shroud and then place in the calibrating solution. The solution supplied has an EC of 2.77mS/cm (CF=27.7, ppm = 1382). Allow about 5 minutes for the temperature compensation to fully kick-in and then press the menu button to get down to the Calibrate screen. Then press “Enter” to get to the Calibrate sub-menu where you will again press menu to step through this sub menu until you reach the “Calibrate EC” screen. Then press “Enter” again, to get into the “Calibrate EC screen”. Now press either the UP or Down arrow keys to get the calibrated reading to correspond with the Standard calibrating solution (normally 2.77mS/cm, 27.7CF or 1382ppm). When this is achieved, press the save button to save this in permanent memory. Calibrating your Bluelab Conductivity Pen The Bluelab Conductivity Pen comes factory-calibrated, so there is no need to calibrate it for the first use when it is fresh out of the box. Calibration is not required for normal use, but it can help troubleshoot inaccurate readings. If your Conductivity Pen still won’t calibrate properly, replace the calibration solution and confirm the shroud is correctly fitted. Follow these calibration steps: Make sure the pen is clean before calibrating, as shown above, and the shroud is fitted correctly. Rinse the probe in fresh water, then place it into fresh 2.77 EC Conductivity Standard Solution. Press and hold the CAL button for three seconds until ‘CAL’ appears. Then release the button. After this, ‘CAL P’ should be displayed on the screen. If ‘Err’ is displayed, check if the probe is clean and that the calibration solution is fresh and uncontaminated. Finally, a check mark will appear on the screen to indicate successful calibration. This check mark will disappear after 30 days, indicating it is time to recalibrate. Why should I calibrate my Bluelab Conductivity Pen? Calibration ensures your Bluelab Conductivity Pen is measuring EC and PPM accurately. Small measurement drift can occur over time due to regular use, residue buildup, and general wear. Regular calibration allows the pen to reset and check its readings against a known reference value, so you can confirm that the readings you see match the actual conductivity of your solution. Without calibration, even a clean probe can slowly drift away from true values, leading to incorrect nutrient strength readings and adjustments. Calibrating your Conductivity Pen helps ensure consistency, and accuracy. This means you can measure and adjust your nutrient solution with confidence. When is calibration required for my Conductivity Probe? Your Conductivity Pen comes factory-calibrated, so calibration is mainly recommended as a troubleshooting step. Calibration is recommended when: Readings are different from what you expected. The probe has been cleaned and you want to ensure accuracy. The pen has been dropped or handled roughly. You are experiencing inconsistent or fluctuating readings. The reading in 2.77 EC standard solution is not within ±0.1 EC (±1 CF) after cleaning. Note: Always clean the probe before calibrating and use fresh, uncontaminated 2.77 EC Conductivity Standard Solution for best results.
