Find answers and solutions to common questions for the Bluelab OnePen and replacement probe.
In this guide:
General questions
My Bluelab OnePen product won’t calibrate, what should I do?
The first step is to make sure the glass bulb of the probe is both well hydrated and clean.
If, after both hydrating and cleaning, your OnePen still won’t calibrate, the replacement probe may be at the end of its life. Please reach out to our support team if you have further questions.
My pH reading is stuck on 7 pH, what should I do?
Inspect the glassware for damage. If the pen reading is stuck on 7 pH (or close to that), it is likely the glassware is damaged. The replacement probe likely needs replacing.
My pH probe has accidentally dried out, what should I do?
The probe must be rehydrated for 24 hours in KCI storage solution (never use RO, distilled or de-ionised water). Rinse the probe in fresh tap water add fresh KCl Storage Solution to the sponge in the storage cap before replacing the cap. Leave for 24 hours before calibrating the probe to two points following the calibration article, to check the probe hasn’t suffered permanent damage.
Note: Do not soak the titanium electrodes in KCl storage solution.
Important: Whenever storing your Bluelab OnePen ensure the sponge in the storage cap is wet with KCl Storage solution.
There is a salt crust on my probe – why?
Both the pH probe and the storage cap contain KCl (Potassium Chloride) solution. The result of a small level of evaporation of KCl is the formation of a salt crust as KCl is a type of salt.
This salt crust is normal and will not harm the probe or meter. Gently wash the salt off under fresh running water. It is essential to ensure that your probe always has sufficient KCl in the storage cap to remain hydrated.
What is the maximum EC value of the OnePen?
10.0 EC. The conductivity measurement range is 0.0 EC - 10.0 EC or 0 - 100 CF, 0 - 5000 ppm 500 (TDS), 0 - 7000 ppm (ECx700), 0 – 10.0 mS/cm.
How long will my Bluelab OnePen Replacement Probe last?
Bluelab's pH products are charged with reference material which expends over time and use. The average life span of a OnePen™ Replacement Probe is approximately 18 months. Good care will help to maintain your probe. Follow our guides for proper hydration, regular cleaning and calibration.
The OnePen™ probe has a 6-month warranty so if you encounter any issues with your current unit, please feel free to reach out to us for support. With proper care and maintenance our pH products have been known to last for years, being an electrochemical sensor by nature, the performance will deplete eventually much like a battery - taking the best care will allow you to get the most out of your OnePen.
We recommend that you rinse your probe after each use to ensure it's not stored with residual salts from what you've been measuring. You can find more information on cleaning, calibrating and hydrating your Bluelab OnePen™ at support.bluelab.com.
The OnePen™ has a 1-year warranty so if you encounter any issues with your current unit, please feel free to reach out to us for support.
Can the Bluelab OnePen be continuously submerged in a tank?
Yes! It is IP68 certified water proof and is fully submersible.
What is KCl Storage Solution?
Our Bluelab pH Probe KCl (Potassium Chloride) Storage Solution is a storage solution designed specifically for use with Bluelab Replacement Probes or pH Probes.
Storage solution is used to ensure a pH probe is kept in ideal conditions during storage, while the probe is not in use. Read more about KCl solution.
My Bluelab OnePen won’t pair with Edenic?
Make sure you have Bluetooth switched on, on your mobile device. Ensure permission for Edenic to use Bluetooth has been allowed. Confirm that your OnePen is not currently paired with another mobile device, the Bluetooth icon should be flashing. When pairing make sure both OnePen and mobile device are within 10 meters of each another and the OnePen is turned on.
The Bluelab OnePen™ display can be customized via the Edenic app.
The defaults are Backlight On Time 1 minute, Auto Off 4.5 minutes and Brightness 40%.
Understanding error messages
|
Error code |
Reason |
Correction |
|
"UR" pH under range "OR" pH over range |
Solution being measured is outside of pH range of pH0.0-pH14.0 |
Dilute the solution to be measured. |
|
Probe has been allowed to dry out or not clean. |
Follow the cleaning and calibration steps. |
|
|
Probe damaged. |
Check the probe for damage and replace if damaged. |
|
|
"FAIL OFST" displayed when calibrating pH7 |
Calibration solutions maybe contaminated. |
Always use fresh calibration solutions. |
|
Calibration sequence incorrect. |
Always calibration pH7 first then either pH4 or pH10. |
|
|
Probe has been allowed to dry out or not clean. |
Follow the cleaning and hydration steps. |
|
|
Glassware has aged or maybe damaged. |
Check the probe for damage and replace if damaged. |
|
|
"FAIL GAIN" displayed when calibrating pH4 or pH10 |
Calibration solutions may be contaminated. |
Always use fresh calibration solutions. |
|
Calibration sequence incorrect. |
Always calibration pH7 first then pH4/pH10. |
|
|
Probe has been allowed to dry out or not clean. |
Follow the cleaning and hydration steps. |
|
|
Glassware has aged or maybe damaged. |
Check the probe for damage and replace if damaged. |
|
|
"FAIL UNST" displayed during calibration |
Calibration solutions may be contaminated. |
Always use fresh calibration solutions. |
|
Probe not hydrated or clean. |
Follow the cleaning and hydration steps. |
|
|
Probe still coming up to solution temperature. |
Soak the probe in the calibration solution to allow it to reach the same temperature as the solution. |
|
| Glassware has aged or maybe damaged. | Check the probe for damage and replace if damaged. | |
|
"UR" EC under range "OR" EC over range |
Solution being measured is outside of EC range of 0.0-10.0EC. |
Dilute the solution to be measured. |
|
The probe may be dirty. |
Follow the cleaning steps. |
|
|
Probe damaged. |
Replace the probe. |
|
|
"UR" Temperature under range "OR" Temperature over range |
Solution being measured is outside of range of 32°F-122°F (0°C – 50°). |
Adjust the temperature of the solution to be measured. |
|
Probe damaged. |
Replace the probe. |
|
|
Displayed on screen |
Temperature sensor damaged. |
Replace the probe. |
Troubleshooting
|
Trouble |
Reason |
Correction |
  |
Your probe is currently in excellent condition and has been successful calibrated for pH. |
N/A |
|
|
It has been 30 days since the last successful pH Calibration. |
Perform a pH Calibration. |
|
|
Last calibration was okay but not excellent. · Contaminated calibration solutions · Dirty probe · Aging glassware |
Clean the probe and re-calibrate in fresh calibration solutions. Still occurring then consider replacing the probe. |
|
(Flashing) |
Last calibration was unsuccessful. · Contaminated calibration solutions · Dirty probe · Damaged probe · Aged glassware |
Check for damage before cleaning and re-calibrating in fresh calibration solutions. Still occurring then the Probe needs replacing. |
|
(Flashing) |
Available to connect to Bluetooth |
Will stop flashing when paired and used with Edenic. |
|
pH reading inaccurate |
Using factory default calibration. | Calibrate pH. |
| Glassware not clean. |
Clean glassware, hydrate, then calibrate. |
|
|
Wick contaminated or blocked |
Soak probe in KCl storage solution for 24 hours and retest. Don't measure proteins or oils with the OnePen. You may need to replace the probe. |
|
|
Glassware aged or damaged. |
Replace Probe. | |
|
pH calibrated with contaminated calibration solutions. |
Re-calibrate in fresh calibration solutions. | |
|
Noisy – readings jumping around |
Contact zone not immersed correctly. |
Lower pen into solution at least 2cm/1". |
|
Reading stuck on 7 pH |
Broken glassware. |
Replace the probe. |
|
Incorrect sample reading following successful calibration |
Wick blocked. |
Soak probe in KCl storage solution for 24 hours and re-calibrated. Don't measure proteins or oils with the OnePen. |
|
Incorrect EC sample reading |
Electrodes are dirty. |
Clean probe and perform EC check in Bluelab 2.77 EC Conductivity Calibration Solution |
|
“Low Batt OFF” |
Batteries are low. |
Replace batteries. |
|
Scrolling text: “PROBE INVALID FAKE OFF” |
Incorrect probe has been connected. |
Only use official Bluelab OnePen Replacement Probes. |
(Flashing)
(Flashing)
Additional information regarding the Bluelab OnePen/Replacement Probe can be found in the maintaining your Bluelab OnePen Probe guide.