FAQ and troubleshooting for the Bluelab Conductivity Pen

Find answers and solutions to common problems

General questions

Why is my conductivity pen reading lower than I expect?  

Nutrient solutions, fertilisers and salts can build up on your conductivity probe and cause the Conductivity Pen to read lower than you might expect. We recommend cleaning and testing your pen in EC 2.77 solution at least once every month to remove residue. 

Follow the troubleshooting guide below for more on inaccurate readings. 

Does the Bluelab Conductivity Pen need calibrating? 

Only in some cases. When you first buy your pen, it is factory calibrated. Once you've had your pen for a while, and if, after cleaning, the pen still reads low or high in 2.77 EC Standard Solution, you can calibrate your pen to regain accuracy.

Follow the calibration guide

Troubleshooting guide


Trouble Reason  Correction
Conductivity pen gives low readings Dirty probe head. The electrodes on the probe head are easily contaminated with oils and greases, for example, from fertilisers and organic nutrients, and even your fingers. Try not to touch the probe head for this reason. Clean and verify in 2.77 EC standard solution
Conductivity pen gives high readings Solution could be old or contaminated.  Clean and verify unit in 2.77 EC
Probe shroud not attached Ensure probe shroud is attached
Display does not turn on Battery low Replace battery using the pen battery replacement guide
Broken pen Replace the conductivity pen

Error messages


Error message displayed Reason  Correction
Temperature under range Solution may be too cold 
Temperature over range Solution may be too warm
Solution over range Clean the conductivity pen using the cleaning instructions
Temperature error Hardware error. Replace the pen if needed.
Hardware error  Conductivity pen damaged. Replace unit. 


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