Just got my Blue Lab Truncheon

[LEDNewbie]

So looking at my Blue Lab Truncheon, there is a EC x 500 = PPM and a EC x 700 = PPM. Witch one do I look at when people say they are running 1200 or 1300 ppm's??? Why exactly is there two scales? Thanks guys....

 

[cvk]

bought one yesterday myself. most u.s. nutrient company's use the 700 scale and european nutrient co's use the 500. Read label on your nutrients and it should be listed on there

 

[LEDNewbie]

bought one yesterday myself. most u.s. nutrient company's use the 700 scale and european nutrient co's use the 500. Read label on your nutrients and it should be listed on there

Ahhhhh, OK. Sweet. Thanks

 

[FlowerFarmer]

There in lies the problem,
Why not just use EC since that is what these meters read?

Avoid the confusion in the 1st place.


Stating PPM is pointless if one does not know the conversion a poster is speaking in.
...yet it seems that nearly everyone does it.

 

[PoopyTeaBags]

bought one yesterday myself. most u.s. nutrient company's use the 700 scale and european nutrient co's use the 500. Read label on your nutrients and it should be listed on there

i always though it was the other way around


.5 is us
.7 is eu

ec is universal

but then again i also thought

tds =.5

and

ppm =.7

honostly i wish someone would clear this up at this stage in my career you think i would know this basic info....

 

[unspoken]

Poopy, ppm is the unit that tds is measured in. like weight is measured in grams, tds is measured in ppm. Honestly for our situation it would be better if everyone used ec. just less confusing for people

 

[PoopyTeaBags]

see i thought that also and then i bought a blue lab gaurdian... and it says tds ppm and ec...


tds is measured .5

ppm is .7 and e c is normal ec obv

 

[unspoken]

ok, so say you have 1000 "tds" 1000 total dissolved solids? 1000 what? ... There is no unit there. That's like saying how long is that? 5. 5 what? 5 length. It's 1000 parts per million (or mg/L).

All elements have some electrical charge. Therefore, it is possible to closely estimate the quantity of TDS by determining the EC of the water. However, since different elements have different charges, it is necessary to convert the EC to TDS using a scale that mimics the charge of that water type. The following are the most common water samples, and for the COM-100, each has its own conversion factor:

KCl:
Potassium Chloride is the international standard to calibrate instruments that measure conductivity. The COM-100 is factory calibrated with a 1413 microsiemens solution is the default mode is EC-KCl. The KCl conversion factor is 0.5-0.57.

442TM:
Developed by the Myron L Company, 442TM simulates the properties of natural water (rivers, lakes, wells, drinking water, etc.) with a combination of 40% Sodium Bicarbonate, 40% Sodium Sulfate and 20% Chloride. The 442 conversion factor is 0.65 to 0.85.

NaCl:
Sodium Chloride is used in water where the predominate ions are NaCl, or whose properties are similar to NaCl, such as seawater and brackish water. The NaCl conversion factor is 0.47 to 0.5.

^ That kind of explains why there are different conversion factors. Really the only way to measure "TDS (ppm)" without measuring ec then converting it would be to fill a liter of your solution and then evaporate the water out and weigh in milligrams whatever is left over after the water is gone. That is total dissolved solids expressed in ppm (or mg/L). Obviously that is a pain in the ass so we just measure ec and convert to ppm(mg/L) using a conversion factor. EC only really measure how much electricity your solution conducts in m/S or u/S.

Measurements in EC (µS) do not have a conversion factor, but do require the correct setting for the proper temperature coefficient.

Hope that clears it up for you once and for all. haha