TDS meter

[staman]

Can you use a TDS meter to measure the salinity of the water? My digital pen gives measurements in mS (millisiemens)
I know theres a formula :

uS*0.6=ppm

Apparently this isnt exact though...

 

[mystikdragon7]

I would say no, becuase your TDS meter will read off of the scale.

 

[staman]

I think i follow what you mean.....

At 35 ppt or (35,000ppm) i get

uS=35000/0.6=58333.33

Therefore my pen should read 58.333 mS

Well see if it goes that high. My question is how accurate is the 0.6 approximation. Its my understanding that ppm pens simply measure EC and then convert it to ppm with said formula

 

[liao]

References by Randy
TDS

 

[staman]

That article says 35 ppt converts to 53mS/cm. I wonder if theyre using 0.65 as an approximation instead of 0.6. What do you guys think of the crappy hydrometer at petco,petsmart etc...