I have TDS solution 1000 ppm NaCI ,at 25C/77F.
Small print under 1000 ppm it says.....1060 as KCI -1450 as 442-2000ps
I read this on HM digital website and not sure I calibrated it correctly.
"For example, 1060 ppm KCl = 1000 ppm NaCl. Therefore, if you have a 1060 ppm KCl calibration solution, but a meter with the NaCl conversion factor, such as the TDS-3, you can still calibrate the TDS-3 with the KCl calibration solution. In other words, if putting the TDS-3 into a 1060 ppm KCl solution, the meter should read 1000 ppm."
So when I set my meter to KCI ppm and dip it in the 1000ppm solution should my meter read 1000ppm or 1060 ppm ?
Thanks and sorry for Hi-Jacking your thread .
The following should help you to understand. As it states, NaCL is most closely related to hydroponic nutrients. Because the meter comes calibrated by NaCL by default, your meter should read 1060ppm if you dip it in KCl.
The following is from:
https://www.rollitup.org/newbie-central/290668-ec-tds-meter-help-needed.html
posted by someguy15
Difference is what chemical it is basing it's PPM 'guess' off of. All PPM meters are EC meters that convert. I prefer to use the NaCL EC setting on mine, and then convert to ppm (.5) or ppm (.7) depending on situation using the scale below. The only difference between the 3 ec settings are the temperature compensation curves. I choose EC NaCl.
(EC(mS))—(PPM.5)—(PPM.7)—(CF)
.4———200————-280———–4—–seedling/ rooted clones
.6———300————-420———–6—–
.8———400————-560———–8—–veg
1.0——–500————-700———-10
1.2——–600————-840———-12
1.4——–700————-980———-14
1.6——–800————-1120———16—–aggressive
1.8——–900————-1260———18
2.0——–1000————1400———20—–super aggressive
2.2——–1100————1540———22
2.4——–1200————1680———24
So if it reads 956, your ec is .956.... if it reads 104 and the x10 symbol is blinking, this is 1.04 EC, make sense?
Reason I prefer EC is it never changes. Too often people throw around PPM measurements and never note if its the .5 or .7 scale. As you can see this makes a big difference... at 1EC, the (.5)ppm is 500, but the (.7)pmm is 700. If the person doesn't mention what scale, we really have no clue which to choose.
With this meter you can measure EC (NaCL, 442, KCL) or PPM (NaCl & KCL are .5 scales) and (442 is a .7 scale)
What is the best way to calibrate a TDS or EC meter?
Answer: Standard reference solutions are used. The bottles are marked with the conductivity (EC) value in milliSiemens/cm and the corresponding ppm values for sodium chloride (NaCl) and potassium chloride (KCl) solutions, and sometimes for a "442" reference mixture. The conductivity of sodium chloride solutions is close to that of hydroponic mineral nutrients, so a "1000-ppm NaCl" standard is most frequently used when calibrating the meter for hydroponic solutions. You should follow the calibration instructions in the manual, which the manufacturer of your meter provided.
Source:
http://generalhydroponics.com/site/index.php/resources/faqs/tds_ec_ppm/
