R2 Calibration

NewBoyUK

I’m having a play with my R2 - do you use distilled water or the water from the machine to calibrate?

Surely if the machine water already has TDS in it - you want to compare vs that for a true reading - not pure distilled as it won’t take this into account?

Would it make that much difference in final readings?

dfk41

NewBoyUK I know Dave in his review just used RO water from his Osmio

MWJB

NewBoyUK You should use distilled because you are calibrating the refractometer, not the coffee. Distilled water has a known refractive index. Coffee refractometers are not the best tool for reading water TDS, their scale is tuned to coffee at 12,000 to 120,000ppm typically, so your 150ppm (perhaps) brew water isn’t significant.

NewBoyUK

dfk41 it’s playtime 😁