Just saw this thread referenced from another about the Ca ion meter. Does anyone know if this works as advertised? I have seen others that I think do a few other ones that are also of interest.
http://www.qasupplies.com/cardyionmeters.html - NaCl, Nitrate, Na, and K.
I think they are made by Horiba -
http://global.horiba.com/products_e/.
WTW also makes some
http://www.wtw.de/us/index.html.
I have never purchased one but I like the idea. Anyone out there have any idea how well they work? It would be nice to know about repeatability, stability of calibration, accuracy, etc. Seems like they would be much easier than test kits, and possibly far more accurate (not so prone to operator error).