Page 2 of 2 FirstFirst 12
Results 26 to 34 of 34

Thread: PH probe not calibrating right.

  1. #26
    New User
    Join Date
    May 2018
    Location
    UK
    Posts
    2
    Hi there,

    I am having the same issue with both PH and conductivity. Thanks for posting a walk through. Couple of questions

    When using Apex local do you need to be signed into you account. Also , what does power cycled Apex Controller fully mean?

  2. #27
    Frequent Contributor zombie's Avatar
    Join Date
    Dec 2013
    Location
    Denver, CO
    Posts
    13,176
    Quote Originally Posted by teast View Post
    Hi there,

    I am having the same issue with both PH and conductivity. Thanks for posting a walk through. Couple of questions

    When using Apex local do you need to be signed into you account. Also , what does power cycled Apex Controller fully mean?
    You don't have to be signed into fusion to use apex local. They are completely seperate.

    He is saying he got better results by rebooting the controller before calibrating. A reboot before or after calibration doesn't have any effect IME, so that step is not necessary.

    You might be an engineer if...You have no life and can prove it mathematically.

  3. #28
    Regular Vistor
    Join Date
    Apr 2018
    Location
    Seattle
    Posts
    17
    Quote Originally Posted by teast View Post
    Hi there,

    I am having the same issue with both PH and conductivity. Thanks for posting a walk through. Couple of questions

    When using Apex local do you need to be signed into you account. Also , what does power cycled Apex Controller fully mean?
    Apologies for my delayed responses, had some busy recent days.

    So I struggled heavily to calibrate my conductivity probe many times, like the readings wouldn't even change no matter what I did during the cal process (man. cal, auto cal, quick-reset cal, using Apex Local or Fusion).

    When I say "power cycle fully," I mean a 5-15s power-down where nearly all residual voltage will bleed out of the components. I had to unplug my PMUP power supply, too, as it fed some voltage back to the Apex via the PMUP>FMM>Aquabus cable.

    After power cycling the Apex and letting all Neptune components power down for ~9s, the next attempt to calibrate my cond. probe worked perfectly (using the same methods as before), which is why I left it in my step-by-step process.

    A full power cycle may not be necessary for calibration, but rebooting any electronic component is a good place to start when troubleshooting, even for the simplest of microprocessors.

  4. #29
    Frequent Visitor
    Join Date
    Dec 2015
    Location
    Vernon, New Jersey
    Posts
    75
    Hi,

    I have an American Marine Pinpoint PH meter which I trust. When I calibrate my PH probes using the Apex software, I can never get it to match the Pinpoint Meter. Is there a way to tell Apex what I want the PH set to like I do when I calibrate the temp probe or is the only way to do it through the software? I have three probes and they are all off by around .5.

    Thanks

  5. #30
    Regular Vistor
    Join Date
    Apr 2018
    Location
    Seattle
    Posts
    17
    Quote Originally Posted by Jwcollect View Post
    Hi,

    I have an American Marine Pinpoint PH meter which I trust. When I calibrate my PH probes using the Apex software, I can never get it to match the Pinpoint Meter. Is there a way to tell Apex what I want the PH set to like I do when I calibrate the temp probe or is the only way to do it through the software? I have three probes and they are all off by around .5.

    Thanks
    Did you try following my walk-through process I wrote out at the bottom on the previous page in this thread? I feel that process should address most of the commonly encountered challenges, as I happened to have encountered every common problem, apparently

    Unfortunately there is no way to manually adjust the pH calibration, unless you just mentally make the adjustment. Mine was 0.4x off for a month, I just knew that ~7.8x=~8.2x

    Try my full step by step process and see if you get better cal results.

    What is your probe reading in each of the pH cal solutions after performing a calibration and then testing the probe in each solution (7x and 10x)?

  6. #31
    Frequent Visitor
    Join Date
    Dec 2015
    Location
    Vernon, New Jersey
    Posts
    75
    Thanks, I'll check out walk-through process. 7 - 726 and 10 - 1016. Temp Comp = disabled, offset = -42 and scale 1.08d.

  7. #32
    Frequent Visitor
    Join Date
    Feb 2014
    Location
    Lausanne Switzerland
    Posts
    182
    Quote Originally Posted by otter_water View Post
    Successfully re-calibrated my pH probe tonight:

    1. Power cycled Apex Controller fully.
    2. unplug pH probe.
    3. use Apex Local for calibration/setup.
    4. pH temp compensation - Enabled.
    5. perform rapid manual calibration process w/probe disconnected to reset the pH cal.
    6. plug in pH probe.
    7. perform manual calibration via Apex Local.
    8. wait 5mi to settle w/each cal fluid (numbers settled ~719 and ~999).
    9. pH:10.01 cal solution read an even 10.0 after calibrating - now my tank reports a proper 8.17x


    I believe these factors were causing me issues between both pH and Cond probe calibrating:
    - Apex needed a power cycle,
    - using Apex Fusion for calibration is less successful/consistent.
    - Cond probe does not want/need to be dried for hours.

    I feel I could get any Apex to properly calibrate pH and Cond with my knowledge now. Thanks for your guy's help!
    I will try this as i am having issues with my pH. Not sure if it's the port though, have ruled out the probe but worth giving this a go.

    Thanks for the good write up

  8. #33
    New User
    Join Date
    Feb 2020
    Location
    Florida
    Posts
    1

    pH probe concave calibration error

    Hello everyone! Not too kick a dead horse again but here it goes. I am having same issue. Using a pinpoint pH monitor and apex pH. A few weeks ago I had both monitors calibrated exactly! I have never achieved this before, it was so cool! But pH drift affect one or the other and now I am re-calibrating, or at least trying.

    I have read all the threads...and followed directions.... plus I have a pH in biomedical sciences and have years of lab experience, so this is very frustrating!

    The first thing I noticed was in the local screen for pH control the offset and scale were way off, didn't write those down. I performed the reset process getting the offset back to -92 and scale to 1.114

    Ran manual calibration pH 7.00 solution at 6.99 and pH 10.00 at 9.99, very happy with that, I moved them back and forth with consistent readings.
    Clicked update settings and the offset changed to -31 and scale to 1.09b (yes b) all I can think of is slope equation of y=mx+b but I have no real idea.
    Placed probes back in respective solutions and got 6.99 and 9.99 ; pinpoint 7.00 and 9.99

    Placed probes in tank... 8.01 for pinpoint and 7.90 for Apex. Assuming the pinpoint is closer to correct, its the middle of the day and lights are running full blast, so would actually expect levels to be closer to 8.2 to 8.3

    Any ideas, I remember something from analytical chemistry about concave and convex calibration curve errors and I can see that my apex curve is dropping between too calibration points, this should have gone away after resetting....

  9. #34
    Regular Vistor
    Join Date
    Apr 2018
    Location
    Seattle
    Posts
    17
    Quote Originally Posted by stevebhammer View Post
    Hello everyone! Not too kick a dead horse again but here it goes. I am having same issue. Using a pinpoint pH monitor and apex pH. A few weeks ago I had both monitors calibrated exactly! I have never achieved this before, it was so cool! But pH drift affect one or the other and now I am re-calibrating, or at least trying.

    I have read all the threads...and followed directions.... plus I have a pH in biomedical sciences and have years of lab experience, so this is very frustrating!

    The first thing I noticed was in the local screen for pH control the offset and scale were way off, didn't write those down. I performed the reset process getting the offset back to -92 and scale to 1.114

    Ran manual calibration pH 7.00 solution at 6.99 and pH 10.00 at 9.99, very happy with that, I moved them back and forth with consistent readings.
    Clicked update settings and the offset changed to -31 and scale to 1.09b (yes b) all I can think of is slope equation of y=mx+b but I have no real idea.
    Placed probes back in respective solutions and got 6.99 and 9.99 ; pinpoint 7.00 and 9.99

    Placed probes in tank... 8.01 for pinpoint and 7.90 for Apex. Assuming the pinpoint is closer to correct, its the middle of the day and lights are running full blast, so would actually expect levels to be closer to 8.2 to 8.3

    Any ideas, I remember something from analytical chemistry about concave and convex calibration curve errors and I can see that my apex curve is dropping between too calibration points, this should have gone away after resetting....
    How old is your Apex pH probe? Is it one of the double junction pH probes or single junction? I hear the double junction should last longer. I've also been told that any brand lab grade pH probe is compatible with the Apex, so maybe that can help you troubleshoot by swapping probes around or trying different/higher grade/newer probes.

    I also find it helpful to have a pH test kit around to give me a reagent method of testing pH against my probe.

Page 2 of 2 FirstFirst 12

Similar Threads

  1. Help! New PH probe not cAlibrating
    By Faulker's Maze in forum AquaBus Modules, Probes, and Breakout Boxes
    Replies: 0
    Last Post: 02-15-2022, 19:06
  2. Question: Calibrating pH Probe
    By drblank1 in forum AquaBus Modules, Probes, and Breakout Boxes
    Replies: 1
    Last Post: 01-06-2022, 06:44
  3. Help! Calibrating pH Probe
    By drex in forum AquaBus Modules, Probes, and Breakout Boxes
    Replies: 12
    Last Post: 10-19-2016, 05:58
  4. PH probe calibrating
    By tasso in forum AquaBus Modules, Probes, and Breakout Boxes
    Replies: 13
    Last Post: 04-15-2013, 12:35
  5. Calibrating a 2nd pH probe
    By mousefish in forum AquaBus Modules, Probes, and Breakout Boxes
    Replies: 2
    Last Post: 03-07-2013, 23:55

Bookmarks

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •