PPM, which EC conversion do you use?
- Thread starter bluenorth
- Start date
StinkyFgrs
Member
Yas all are still livin in the 1800s ! Big Mike says ya can throw those fuckers away.Thats just Purrrrfect.Only $999.99 to get ya through veg,then ya can really spend like a Steamer when ya flip em.
converting from ec, is like beating your head against a wall.
It doesnt help anything, and only adds to your confusion!
Somewhere in this thread, it should also be noted none of these 'ppm' meters actually measure parts per million. They all measure ec, and then use a (superfluous) conversion.
It doesnt help anything, and only adds to your confusion!
Somewhere in this thread, it should also be noted none of these 'ppm' meters actually measure parts per million. They all measure ec, and then use a (superfluous) conversion.
L
lysol
Beg to differ. My digital oakton can do .51 if I so choose. Also my truncheon is off by 100ppm at higher ecs, according to different calibration fluids I've used. My digital oakton stays calibrated. The truncheon boasts "no need to calibrate". My response is "yeah right, more like no WAY to calibrate". It works decent for what it is, although for the $100 I'd go for digital 4 in 1 oakton. Even the temperature correction is digital and therefore instant, contrasted with the truncheons 2 minute required temp acclimation.
Micro semens are best, they have the fine granularity of a "ppm" meter, but don't like because micro semens are just a smaller unit for measuring conductivity (which is the same thing ec measures, which is apparently good enough for you)
my 4 in 1 oakton does micro semens too. micro semens is basically "double what your ppm would be on a .5 meter". so 1,000 micro semens = 1ec, or about 500ppm
EC is the only way to go. PPM is arbitrary. EC is always the same.
Found this beauty on ebay for $65. I'll put her up against any Truncheon.
Found this beauty on ebay for $65. I'll put her up against any Truncheon.
L
lysol
Sgt.Stedenko,
The meter's estimation of PPM is not arbitrary, not at all.. it is the product of the EC and and a fixed (known) constant.
Yes that thing looks much better then a truncheon. Anything that can be calibrated is better, by definition ;-) .. the very definition of the word calibration uses "correctness" to define it.
The meter's estimation of PPM is not arbitrary, not at all.. it is the product of the EC and and a fixed (known) constant.
Yes that thing looks much better then a truncheon. Anything that can be calibrated is better, by definition ;-) .. the very definition of the word calibration uses "correctness" to define it.
Nah dude, I meant comparing your ppm measurements to others and wondering why your plants shown signs of nuteburn.
mS/cm (micro siemens per centimeter) is 1/500th your "PPM" on the 500 scale. Example: 1mS/cm=500 "PPM". EC is like temperature. "1 temp" expresses nothing. The temperature must be measured on a scale such as 1º Kelvin, 1º Celsius, etc. As EC is most commonly denoted in mS/cm and you've used mS in your example, without further denotation, 1000mS=1000EC.
I think you've confused mS/cm with µS/cm or, milli siemens per centimeter. 1 mS=1000µS, 1000mS=1,000,000 µS.
It's completely arbitrary.
If I said that 500, 640, 650, 680, 700 and 768 were identical numbers you'd call me a moron. If I said 550 is a stronger solution than 750, you'd call me brain dead. Why does "PPM" get a break for so blatantly lying to you with arbitrary nonsense?
If "500" weren't arbitrary it would be the only conversion instead of 1 out of (at least) 8 different scales.
L
lysol
I agree, if you are going to use a meter that estimates PPM for purposes of comparing to others, make sure you are both on the same conversion factor.
.. and Freezerboy... yes I guess meant per cm. Although it looks like I'm not the only one who leaves that part off (however improper notating it like that may be)
I found this helpful link too. http://www.lenntech.com/calculators/tds/tds-ec_engels.htm
.. and Freezerboy... yes I guess meant per cm. Although it looks like I'm not the only one who leaves that part off (however improper notating it like that may be)
I found this helpful link too. http://www.lenntech.com/calculators/tds/tds-ec_engels.htm
L
lysol
You counfused mS with ec! 500 ppm correspond to 1000 μS / cm or 1 EC
μS is "about double" your "ppm", not 1/500th... always.
http://www.lenntech.com/calculators/tds/tds-ec_engels.htm
Question to you though? What do you mean EC is denoted in μS/cm? You mean instead of writing "1ec" most scientists would write "1,000μS/cm"? How the heck did you arrive at 1,000μS/cm == 1,000 ec?
As far as I can see, a μS is 1E-6 * 1EC
Edit: OH I GET IT NOW "EC" LIES TOO! We are luckly all of our EC meters are measuring in Siemens, but just like ppm, someone else's meter could express EC in microsiemens, nanosiemens, picosiemens, etc... Oh the irony of the people bashing PPM.
So EC is like "temp". expresses nothing, must cast it to units "1 EC in μS"
Same with PPM then, it does express something, you just first must cast it to which solids (ex. NaCl)..
I'd rather be off by a factor of .2 then a factor of 1,000 anyday!
L
lysol
According to you EC gets the same break because EC does not specify the units either.
"arbitrary nonsense". come on, lets not resort to name calling ;-)
I've confused nothing. mS/cm and µS/cm are the scales by which EC are measured. Without the scale, EC has the same numerical value as "temperature."
Straddle the border of Canada and the US with 2 glasses of 100º water. The US cup is body temp while the Canadian cup is boiling. This is because the US uses Fahrenheit and the rest of the world uses Centigrade.
1 mS=1000µS because that's how "milli" and "micro" relate by definition. It's not a lie to say 1 meter=1000 millimeters or that 1$=100¢. One meter IS 1000 millimeters, 1$ IS 100¢, and 1mS IS 1000µS. Those are their defined values.
PPM is Parts Per Million (a measurement our pens and meters cannot make) It means of 1,000,000 parts, X number of parts are whatever it is you're measuring. 500 PPM means 500 of 1,000,000 parts; 700 PPM means 700 of 1,000,000 parts. Those are two different values, they are not the same yet, PPM says they're identical. That's not true, that's nonsense. 550 is a smaller number than 750 yet, 550 PPM may or may not be a stronger solution than 750 PPM. That's as arbitrary as it gets.
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Freezerboy, I'd just like to thank you for being the voice of reason in so many threads...
L
lysol
Oh, I had no idea mS and µS meant different things, my mistake. Thanks for learning me!
EC says 1µS and 1mS are identical, if the person doesn't state units.
PPM says 700ppm and 500ppm are identical, if the person doesn't state the conversion factor
If I take RO water and mix in 500ppm of NaCi, my meter reads 500ppm, that's not nonsense.
I am agreeing with you that the meter's estimation of ppm has nothing to do with total dissolved solids. As far as I see we are saying the same thing, except putting different subjective biases on the wording.
grnMtnGrower, stop cluttering the thread with posts that contain no content, please. If you want to thank someone I'd say thanking them once is reasonable.
I've introduced less clutter into this thread than you have with your misinformation. I can't rep Freezerboy or vote his post helpful, so I'm posting my agreement with him. There is no need to post the exact same thing as he is, but he is posting fact, and you were posting bad info. To someone that knows nothing of this subject, you guys are both presenting equally technical terms and numbers, but only one of you is right.
I'll post what I want, where I want. Got a problem? Report my posts. You seem to have a habit of posting bad info, and when I come across it, I will correct it, or agree with whoever does.
First things first. Speaking to no one and everyone in particular, no calling people out on a personal level. OK? OK.
EC says that 1mS=1000µS. 1 milli unit equals 1000 micro units by definition. Its how the metric system works.
Your meter does not measure PPM; It has no clue how many parts of anything are contained in your solution.
EC says that 1mS=1000µS. 1 milli unit equals 1000 micro units by definition. Its how the metric system works.
Your meter does not measure PPM; It has no clue how many parts of anything are contained in your solution.
L
lysol
Agreed. It makes estimations. You need a nutrient calculator and RO water to determine PPM of each element.
salt deflects meter
potassium chloride 100%
ammonium nitrate 90%
sodium nitrate 85%
potassium nitrate & urea 75%
ammonium sulphate 70%
calcium nitrate 45%
magnesium and
potassium suphate 45%
di & mono phosphates 25%
super phosphates 10%
gypsum & limestone 5%
can calculate ec/ppm by hand, as well.
& then convert back/forth to millimhos, by hand.
see link ^
potassium chloride 100%
ammonium nitrate 90%
sodium nitrate 85%
potassium nitrate & urea 75%
ammonium sulphate 70%
calcium nitrate 45%
magnesium and
potassium suphate 45%
di & mono phosphates 25%
super phosphates 10%
gypsum & limestone 5%
can calculate ec/ppm by hand, as well.
& then convert back/forth to millimhos, by hand.
see link ^
