pH Calibration

SimilanRocks

New member
I got a brand new ACjr and lab grade pH probe.
I follow the instructions usng 7 and 10 and I got the message "Probe Defective Restoring"

When 7 is stable, it reads 8.93
When 10 is stable, it reads 0895

Does it mean I got a bad probe? Just wanted to make sure before returning it.
 

kenargo

Premium Member
When you calibrated did you have 2 solutions (PH7 and PH10) and did the display show the values when you had the probes in the calibration fluid? If you did then it sounds like you where doing things correctly and you should contact Neptune support.

Here is the support contact information:

Phone: (408) 578-3022
email: support@neptunesys.com
 

SimilanRocks

New member
Yes I have 2 solutions, 7 and 10. It displays some numbers when the probe is in the fluid. The above numbers are what I got from the steps.

I also tried in the sump, normally my tank is 8.2, it reads 8.66
And tried in limewater, it reads 8.63. So everything I tried it all reads around 8.6 to 8.7 with out the calibration.
 

Tech Diver

New member
Limewater should have a pH of around 12 to 12.5, so it sounds like the probe is defective. You could put a voltmeter on the probe to see if you get any variation as you put it in different pH solutions. Your readings should be on the order of 50 millivolts or so. Plot your readings on a graph and if your values vary fairly linearly with the pH, then your probe is good and the controller is the one that is defective.
 

clp

.Registered Member
It is not really possible to use an standard voltage meter to measure the voltage out of a pH probe. The probes input impendance is way too high. SimilianRocks contact support@neptunesys.com, and I'll help you sort out the problem.

Curt
 

bdare

Salty Dude
Premium Member
If you have the same problem I did you left the cap on the probe! Beginners luck!
 

koyoteturtle

New member
after using the calibration fluid, 7 wait 15 min. wash probe, put it into the 10 calibration wait 15 min push ok. wash probe. Set it as calibrated. Then stick the probe in the 7 calibration fluid. It should read 7 and same witthe 10. I didnt get the right readings either, then on a hunch, after It said it was calibrated at 7 and 10 with about the same readings you had, I washed the probe and stuck it in the 7 solution and it read 7. it works.
 

clp

.Registered Member
Just turn on the second pH probe (pH2) in the setup->pH setup->ph Enable menu.

Curt
 
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