I have a TDS-3 tester. It’s used to test water for total dissolved solids (hence the TDS) and I use it to check up on my Brita pitchers, among other things. To calibrate it the company offers a calibration fluid of a known concentration. I’m pretty sure it’s a saline solution of a known concentration of NaCl. They offer two concentrations: 342 ppm and 1000 ppm.
I ordered it and received the 1000 ppm. What I wanted was the 342 ppm (not sure whether they or I screwed up – not important). My tester is supposed to be calibrated against the 342, not the 1000.
Here’s my question: Does it make sense to dilute the 1000 ppm solution to, say, one third, and then I would have 333 ppm solution? This would be fine for calibrating if this is rational. It’s not worth it to send the stuff back. It’s not very expensive and shipping is almost as much as the stuff itself.