Bifferwine
I am a girl
Anyone with an RODI unit needs a TDS meter to determine if and when their filters need to be changed, and if the unit is working properly. I got my TDS meter off of Ebay probably about 5 years ago for $15. It dawned on me last week that I have never bothered to calibrate it! I should know better -- when I use them for work I have to calibrate them before and after every job.
I bought the correct NaCl calibration fluid off of Ebay ($4.95).
HM Digital 342ppm TDS/NaCl Calibration Solution, 1x3oz - eBay (item 370311918054 end time Feb-24-10 18:04:21 PST)
My TDS was off by about 30 ppm -- luckily it was 30 ppm too high, not too low, so my water was actually cleaner than I had been thinking.
I haven't changed my RODI filters in nearly two years, and the output from it is still less than 10 ppm. Yay!
Don't forget to calibrate all your instruments!
I bought the correct NaCl calibration fluid off of Ebay ($4.95).
HM Digital 342ppm TDS/NaCl Calibration Solution, 1x3oz - eBay (item 370311918054 end time Feb-24-10 18:04:21 PST)
My TDS was off by about 30 ppm -- luckily it was 30 ppm too high, not too low, so my water was actually cleaner than I had been thinking.
I haven't changed my RODI filters in nearly two years, and the output from it is still less than 10 ppm. Yay!
Don't forget to calibrate all your instruments!