[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [APD] pH controller is flipping



Demineralized water won't work.  It has no buffer and any acid/base can
cause
a wide pH swing.

You only need the pH 4 and 7 to calibrate.  The pH probe's response is
linear.  Use 7 for fixed point and 4 for the slope adjustment.

When my pH probe died, it just seems to stucked at a pH but not
swinging like yours.  So I don't know what went wrong in your case.
(I switched to test kits, it's cheaper).
-----------------
Louis Lin
TickQuest Inc    www.tickquest.com


----- Original Message ----- 
From: "pieter cool" <pieter_cool at student.kuleuven.ac.be>
To: <aquatic-plants at actwin_com>
Sent: Thursday, January 08, 2004 3:49 PM
Subject: [APD] pH controller is flipping


Hello all,
I am currently using the seramic ph controller (produced by sera).  Recently
the ph measurements started swinging from 10 to 4 without any reason.  I
tried to reinstall the whole thing, using the test solutions and all.  It
still isn't working properly.  I suspect the ph probe to be broken and the
test solutions outdated as well.
I'm now trying to fix everything.  The easiest solution would be to go to an
LFS and buy a new probe and test solutions but I was wondering if it
wouldn't be possible to use another probe (possibly cheaper).  Has anyone
any experience with this?
My second question is about the test solution of 7 pH.  Wouldn't
demineralised water do the trick.  I thought it has a pH of 7 also.  Am I
wright about this?

I have added a link to the probe I am talking about.

http://www.sera.de/English/autoframe.htm?url=http://www.sera.de/english/start-e.htm

Thanks
Pieter Cool
_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants

_______________________________________________
Aquatic-Plants mailing list
Aquatic-Plants at actwin_com
http://www.actwin.com/mailman/listinfo.cgi/aquatic-plants