Talk:PPM Meter Alt

Revision as of 05:10, 12 March 2009

PPM Meter Discussion

This page is for:

• questions
• comments
• etc...

Temperature Compensation

Has anyone added a temperature compensation function yet??

Shure, why not...

Use the circuit below. No hard to find pieces , cheap and small sensor too

For the diode probe use a piece of shrink wrap tubing for waterproofing

The results for my probe are plotted on the next graph

The precision is pretty good if you make a 2 or 3 point calibration like the one on the above graph

" Sorry for the mess maybe someone will arrange it a little ;0) "

thank you very much, this looks very easy to make! Wikisysop

Interesting reader comments on probe design

Got this in an email, seems useful so posting here:

"I want to measure conductivity in limewater (for a marine fish tank), so I want an electrode for highly conductive solutions (around 10mS/cm).

After a bit of thought, I used two propelling pencil leads (0.7mm diameter) - I needed only a few mm exposed spaced by say 5mm. Readings after a few months are stable, so graphite leads seem ok for this application. (And to calibrate, just draw a line to make the electrode shorter!)

Clearly they're not suitable for everything, but they are readily available."

thanks...

seems you're good not only in electronic stuff but also in water analysis...  :)

Thanks for such informative and helpful project.

any update on those meters?

like to see your project.......possible?

how's your old meter?

tc.