an ohm meter is a waist of time just use a buzzer/tone generator. but still not really needed. i’ve been using UT and raytech for 50 years and don’t use all the gimmicks their putting out there to reap more profit. its your attention to and skill that creates great stones. repeat and time hones those skills and not giving up and not being in a HEARY. i have 6″ raytech’s and i teach faceting and even though i have my methods once i get them started i do expect they will adapt their own way/version of what i taught them.