Hey guys, I'm developing a project to check the water quality, but I can't find any kind of probe or sensor that can measure TAN (Total Ammonia Nitrogen) or even just NH4+ disolved in water. Does anybody know where can I buy it ?
Fifth entry in a google search for "measure total ammonia nitrogen".
jremington:
Fifth entry in a google search for "measure total ammonia nitrogen".
Ammonia and Ammonium ion measurement methods for water analysis
Got you to answer! why use Google!
aside,
I have no idea why someone would attempt to measure something and not know of any tool to use?
What is the chance that the OP can understand what the measurement means if he cannot figure out how to measure it?
Chuck.
I have no idea why someone would attempt to measure something and not know of any tool to use?
What is the chance that the OP can understand what the measurement means if he cannot figure out how to measure it?
You forget to mention that the tool will also have to cost less than $2.
Yes, the OP is likely completely clueless or incredibly lazy, but I was curious to learn whether there might be a probe -- and was surprised that there is! Evidently it has a special membrane separating the electrodes.
jremington:
You forget to mention that it will also have to cost less than $2.00.Yes, the OP is likely completely clueless or incredibly lazy, but I was curious to learn whether there might be a probe -- and was surprised that there is! Evidently it has a special membrane separating the electrodes.
These ISE (Ion Selective Electrode) are available for a growing number of common anions and cations of interest. It's basically an electrochemical cell with some sort of membrane that can only pass the analyte of interest. Works like a pH probe and if you know how to do the math to calibrate it you can read one with any pH meter. They do tend to be quite expensive though, an ISE for ammonia looks to be $500 to $1000. And some of those membranes don't last long and almost none can stand up to constant monitoring.
There are ammonia gas sensors that are supposed to be pretty accurate and if the OP knows his basic chemistry he may be able to exploit one of those. Should be able to find something like that around the chicken industry somewhere. I know they're always monitoring for NH3 gas.
Such probes are very similar to the ubiquitous pH probe, which is also an ion selective membrane (in this case sensitive to the H+ ions in the liquid). The working principle is the same, a thin glass membrane that's sensitive a particular ion, and which then develops a potential across it.
This also means they can not be read directly by an Arduino but require some amplifier circuit.
They do tend to be quite expensive though, an ISE for ammonia looks to be $500 to $1000. And some of those membranes don't last long and almost none can stand up to constant monitoring.
Thanks. I suspected that based on the limited info on YSI's web page -- and the fact that you had to request a quote.