The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: "Tauno Voipio"
References: <3D905023.email@example.com> <firstname.lastname@example.org>
Subject: Re: ph meter using PIC??
X-Newsreader: Microsoft Outlook Express 5.50.4522.1200
X-MIMEOLE: Produced By Microsoft MimeOLE V5.50.4522.1200
Date: Wed, 25 Sep 2002 09:58:38 GMT
NNTP-Posting-Date: Wed, 25 Sep 2002 12:58:38 EET DST
Organization: Sonera corp Internet services
"andy" wrote in message
> tom wrote in message
> > I wonder if there is a good infrared spectrometer way to do
> > this pH measurement? I was looking into that about 15 years ago
> > and never found the perfect spectral wavelength for it. The idea
> > here is that the aquarium liquid is sampled for its absorbtion
> > in a narrow band of the infrared. This band would be at a
> > wavelength of absorbtion of some indicator compound that is added
> > to the water in a known concentration. The abosorbtion of the
> > indicator compound would change, dependant on the pH. The
> > absorbtion would indicate the pH. This would allow a flow-through
> > pH meter that didn't use the old method of a semipermiable
> > barrier.
> > I saw some flow-through spectrometers being sold several years
> > ago. They didn't mention the ability to do pH, they were
> > mostly for juding organic matter content of the water.
> I was working on a flow through system years ago that was designed to
> measure organic matter in water. I beleive the same company was
> concurrently developing a similar method of measuring PH. Don't know
> if they succeeded. I honestly thought they were on to a winner but
> they don't seem to sell either system as yet. Maybe they are still
> working on it..
For a different approach to pH measurement, see:
tauno voipio @ iki fi
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup