Salt reading on SWG (Pentair IC40) off by >1000ppm according to Taylor test

[JoyfulNoise]

Interesting. I checked the salinity again today and both the swg and manual test are now the same. 3600 ppm. Does salinity fluctuate on a daily basis?


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No. Actual salinity does not fluctuate unless you remove large quantities of water. The SWG cell is basically a glorified electrical conductivity meter. Pentair's cell does a fairly poor job of temperature compensation even when the temperature sensor is working. It also only reads salinity once at start up and then once every 12 hours of operating time. The results will vary a little with temperature. This is why it is important to have a K-1766 test kit so you can know the true salt levels and then diagnose problems from there. The SWG salinity output should be considered ballpark at best (+/-500ppm).

 

[ar26pt2]

Salinity doesnt change unless salt or water added (rain). I think the ic40 only takes a salinity measurement every 12h, so I will power it down for a minute if I want it to read fresh. There is slight temp dependency which is supposed to be compensated for but not always. Mine has always read within about 150ppm of the same number (until this sensor failed).