- Sep 23, 2015
- 1,998
- Pool Size
- 20000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Astral Viron V25
Oops, my bad. I thought they were the conversation factors. Taken from the manual. But they are the temperature compensation coefficients, in %. And it’s a simple application, the compensation coefficients are applied when the sample is above 25dC.
The manual doesn’t actually give the conversion factors but implies there are three, one for each mode, 1314, 442, and NaCl. EC to each mode.
Probably a bit confusing but the conversion factors for my meter are given as non-linear. But from memory it’s not a true non-linear conversion but rather two linear factors with a transition point set quite low.
From my home testing, it showed that a calibration point above the read value is slightly better then a calibration point below.
All this highlights the problems associated with a single point calibration meter but if done properly they do work and maybe a viable alternative to the drop test, especially when you consider the broad range of the SWG. Although from what I can tell the Aussie SWG have a broader range then the US ones. Note the results of the test strip, at 5000ppm they were out by ~400ppm but not too bad at 4000ppm. Having said that I don’t use then and the ones I tested were the capillary type not the colourmetric.
I went with the HMDigital because it’s variable calibration as apposed to the Apera Salt20 with a single calibration point at 5000ppm. But 5000ppm works fine and the Salt20 is probably a better meter. Just need to make sure that a decent 5000ppm calibration solution can be found. If I get another meter I believe the Apera EC60 has two point calibration but at 1413μS/cm and 12.88 mS/cm, which are harder to find.
