conductivity and dissolved oxygen probes

aliyesami · Dec 14, 2015

can anyone give me some information about these ? I am building my own monitoring circuit and i just need a salinity/conductivity and dissolved oxgen probe that i can interface with my micro.

thanks

Randy Holmes-Farley · Dec 14, 2015

What do you want to know about them?

Conductivity can be complex as it is a relatively high frequency AC current needed, and the best probes have 4 electrodes.

I discuss such measurements here:

http://web.archive.org/web/20090217...iumfish.com/aquariumfish/detail.aspx?aid=1804

and discuss standards for them here:

Reef Aquarium Salinity: Homemade Calibration Standards by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2004-06/rhf/index.htm

Eric discusses O2 measurements here:

http://reefkeeping.com/issues/2005-07/eb/index.htm

aliyesami · Dec 14, 2015

Randy Holmes-Farley said:
What do you want to know about them?

Conductivity can be complex as it is a relatively high frequency AC current needed, and the best probes have 4 electrodes.

I discuss such measurements here:

http://web.archive.org/web/20090217...iumfish.com/aquariumfish/detail.aspx?aid=1804

and discuss standards for them here:

Reef Aquarium Salinity: Homemade Calibration Standards by Randy Holmes-Farley - Reefkeeping.com
http://reefkeeping.com/issues/2004-06/rhf/index.htm

Eric discusses O2 measurements here:

http://reefkeeping.com/issues/2005-07/eb/index.htm

very useful info learned a lot .
I have already interfaced a PH probe successfully ,but I am unable to find these salinity or dissolved oxygen probes which are for general use and not tied to some specific meter .
can some one point me out to where i can but these probes to use with my design?

thanks

mb165 · Dec 14, 2015

Atlas scientific has conductivity probes for arduino/raspberry pi

aliyesami · Dec 14, 2015

mb165 said:
Atlas scientific has conductivity probes for arduino/raspberry pi

thanks
looks like they are selling the probes with their own meter circuit board, i can but it as a package but I want to make my own circuit. would they be willing to give me the techincal interface info for their probes?

Randy Holmes-Farley · Dec 15, 2015

Conductivity probes are not as standardized as pH and ORP probes, or Ion Selective Electrodes are. The simple fact that conductivity probes have variable numbers of electrodes and electrode surface area and spacing between the electrodes, as well as a built in temperature sensor (for temperature correction of the conductivity) that might be of different types is a strong reason why.