re: Rex Pigeons Flies the Coop & Goes Perpetual in 2015
Looks great Pigeons.
Now that I see the model number of your meter I can look up the manual and find out what sort of conversion ratio it uses to convert it's EC readings to PPM.
I was curious about this because without knowing the conversion ratio there is no way to compare my ppm to your ppm -so to speak. Ha ha I could say something dumb about that statement I just made by I'll refrain and forge ahead here-
Your meter has 3 settings/3 different conversion ratios. (I don't know which one you are set to. The 'standard mode' uses a conversion ratio of .500. Therefore the EC of the reading in your first pic, if you are in 'standard mode' would be a bit less than 1.
(0.992 to be exact -Since your reading is 496 - nearly 500 ppm)
I hope you understand what I mean and this is helpful. It's helpful for me (if you tell me which of the three modes you are set to!) because I can compare my readings to yours- mainly out of curiosity.
Hope you don't mind I'm pasting in the relevant info here.
"The only true method of measuring TDS is to weigh residue found in water after the water has evaporated. You know those spots you see on a glass after you wash it and let it air dry? That's TDS! That residue has mass, and it's possible to weigh it, but if you're not in a lab, it can be tricky thing to do. Therefore, we can estimate TDS levels based on the conductivity of the water since the hydrogen and oxygen molecules of the H2O carry almost no electrical charge. The EC of most other metals, minerals and salts will carry a charge. A TDS meter measures that EC level and then converts it to a TDS measurement. Since different metals, minerals and salts will be more or less conductive than others, there are different conversion factors that can be used.
ppm (parts per million) is the most commonly used scale to measure TDS (Total Dissolved Solids).
µS (micro-Siemens) is the most commonly used scale to measure EC (Electrical Conductivity).
ABOUT TDS and EC
TDS and Conversion Factors
EC: There is no conversion for electrical conductivity. (NOTE: The three EC modes in the COM-100 differ only in their ATC programs. The standard EC mode is KCl.)
TDS - NaCl: 0.47 to 0.50
TDS - 442: 0.65 to 0.85
TDS - KCl: 0.50 to 0.57
(NOTE: Most HM Digital meters use the NaCl factor. The COM-100 has the above three modes, which are user-selected. When converting EC to TDS, the COM-100 uses the non-linear scales, as they would occur in nature, thereby giving you more accurate readings than meters that use linear scales.)
Converting between different scales
PPM Ã µS: The conversion factor of the TDS meter must be known. Once known, the conversion factor should be multiplied by the TDS level. (NOTE: For the COM-100, simply change the mode on the meter. There is no math required.)"