TDS-3 PPM meter calibtated with HANNA 1500... help

Alec420

Well-Known Member
hello, i just got a new TDS-3 meter, it was factory calibrated to a NaCl 342 ppm...
I bought a Hanna instruments 1500 ppm TDS solution
So my meter only shows 3 digit numbers, how do I read my water levels if its 4 digits?
do i just multiply by 2 or what?
This is pretty confusing, plus how exactly do i calibrate it?
 

Aeroknow

Well-Known Member
hello, i just got a new TDS-3 meter, it was factory calibrated to a NaCl 342 ppm...
I bought a Hanna instruments 1500 ppm TDS solution
So my meter only shows 3 digit numbers, how do I read my water levels if its 4 digits?
do i just multiply by 2 or what?
This is pretty confusing, plus how exactly do i calibrate it?
It's very possible that it's set to read EC right now.
I do believe that meter is selectable between EC and different ppm conversion factors.

1500 ppm cal solution is for .7 conversion factor of EC to ppm. Switch the setting to .7 and then calibrate with the 1500 ppm solution.
 

Alec420

Well-Known Member
It's very possible that it's set to read EC right now.
I do believe that meter is selectable between EC and different ppm conversion factors.

1500 ppm cal solution is for .7 conversion factor of EC to ppm. Switch the setting to .7 and then calibrate with the 1500 ppm solution.
well I'll tell you this, I got some RO water and asked for the ppm. they said it was 7 ppm.
I checked the water with my pen with out calibrating it with the hanna solution, it also showed 7 ppm
im not exactly sure on how to switch the setting to .7
 

Aeroknow

Well-Known Member
well I'll tell you this, I got some RO water and asked for the ppm. they said it was 7 ppm.
I checked the water with my pen with out calibrating it with the hanna solution, it also showed 7 ppm
im not exactly sure on how to switch the setting to .7
After reading about that meter a bit, it uses the .5 conversion, and not able to change it. Go get the proper cal solution. 1500 is for models that use the .7 conversion.
Confused yet? Lol
Read this, it should help you understand
http://www.just4growers.com/stream/plant-nutrition-and-growth-enhancers/nutrient-strength-ec,-ppms-and-tds-explained.aspx
 

Alec420

Well-Known Member

Alec420

Well-Known Member
Thanks ! I watched his video this morning, but was still confused.
This link is more informative
im extra confused now, i just talked to the store that sold me the TDS-3 claiming the .5 and .7 conversion does not matter, because the pen shows a 'x' on the side when the ppm will read a 4 digit number.
for example. pen reads 130x =1300 ppm but if the pen reads 130 ppm, there will be no 'x'
 

rkymtnman

Well-Known Member
Yeah, until I have lots of money I'll get like a HANNA stick or something
i've had a $30 HM EC meter for like 5 yrs now. no issues. i think spending more for a good pH meter is well worth it though.

have you got your issue solved?
 
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