Digital scale 09

hi,i bought a digital scale for test 4.It says its a 09 scale.But when i put the first gemstone specimen on it,it won’t register its weight or carat weight.What am i doing wrong?

Hello gemfreak … Before I was a gemologist/appraiser, I was a Metrologist (science of measurement) for the military. I have scales here (electronic balances) that measure down to 1/100,000th of a gram. I overhauled them and they were fully calibrated by an outside lab. If you send me a photo of your scale turned on with nothing on the tare, I may be able to guide you on how to make it work or figure out what you are doing wrong. Best Regards, Michael at The Diamond Grader in Las Vegas.