Originally Posted By: marchboomSeveral things to be aware of when using a digital scale. Any air movement in the room could affect the reading. Even if a fan is in another room air movement could affect to pan and give a bogus reading. You might not notice the air movement but the pan will. Air coming from HVAC vents and open windows also affect scales. I've heard of flourescent lights affecting digital scales but mine has never been affected by it.
You might want to locate your scale and dispenser on a surface other than your reloading bench. This way the movement from operating the press doesn't affect the scale.
kam582,
marchboom has supplied some information on some of the causes that make electronic scales go nuts. I own and use two RCBS Rangemaster 750 scales and run them WITHOUT any interference you might be encountering. First and foremost, as marchboom says, they are very sensitive to wind flow, even breathing directly onto a scale. Thats means NO overhead fans, desk sitting fans, cigarette smoke eliminating fans, or air conditioners OR anything else that causes direct air to blow across the scale. Next is electronic interference, including other appliances being plugged into the same circuit. What I've done is to go down and buy a nice (not cheap) Surge protector that I have my scales plugged into. Nothing else is plugged into that protector. Next, my overhead flourescent lamps are 40" above my reloading table which takes away the probability of light (and the balasts) emitting electronic interference. You also cannot have any electrical appliance that turns on automatically or "cycles" within say 20' because those devices emit an electronic signal when they cycle. Also, no cell phones, computers, TV's, radios or any other electronic device that emits or receives a radio wave signal because your scale will sense that signal as well. In short, when using the scale, limit the conditions that could and will create INTERFERENCE because thos cales are sensitive. Since employing these methods more than two years ago, I rarely have any drift. If I do, one of the formerly mentioned conditions is affecting the scale and isn't all that hard to identify and eliminate.