[denny]

Not to hijack the thread (said the hijacker), but how often does everyone actually calibrate their pH meters? Every use? Every few uses? Every few weeks/months? I usually brew about once a month and got a meter (MW101) a couple of months ago; do I need to calibrate every time? Should I try calibrating it every brew session for a while and see whether it needs adjusting or not?

Mine is a year+ old and I check the calibration every time I use it.  It's almost always right on, but I just don't feel right about using the meter without checking.