For those of you with meters that have a replaceable probe have you done it? I have a Milwaukee 102 and recently I have noticed it takes a long time to get to a number. Long after the hourglass stops it is still changing. I have also noticed that after I calibrate it in 4.01 and 7.01 test solution it will not read that same number when put back in. It will be close but around 3.98-3.99 but not back to 4.01. I have always kept the probe in storage solution and always cool the sample prior to testing so I do not think I have done anything that would cause it to have an issue. One example was this weekend brewing the sample read 5.22 after the hourglass stopped moving but after about 10 minutes it was at 5.39 close enough to my estimated 5.4 I was looking for.