Rebs
If you get close enough fluorescent lamps can affect most unshielded electronic scales through RFI (radio frequency interference) that is broadcast through the air from the lamp tubes, but most often it is scales that plug into a wall that are affected, and that's by EMI (
electromagnetic interference) which often has lower frequency components than RFI, but that are higher frequency than 60 cycles and that is being carried by the power lines. Both are due to the fact fluorescent bulbs have a plasma arc inside that doesn't draw current in a completely smooth way, having small lurches and stalls (noise) that are superimposed on the current average. This noise is coupled capacitively between the ballast windings into the power lines, and can travel some distance down them before dissipating. In your scale this noise contaminates with weight sensor signal.
Motors with brushes make even stronger EMI than fluorescent lamps do, but the cure is the same: you need an EMI filter. Most people use an old computer UPS (uninterruptable power supply) with a dead battery. Plug it into the wall and the scale into the UPS. These have a filter built in.
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Originally Posted by shredder4286
So, do the baffles for the hopper just keep some of the powder above a certain spot, therefor making your charges more consistent? I saw the drawings in your pdf file, just confused about exactly what purpose the baffles serve.
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The powder level in a measure gets lower as you fill cases. This reduces the weight of powder feeding the metering chamber in the measure. In general, when that level is high, the powder is more easily packed down by vibration. It is less so as the level gets lower, tending to make throws with a low powder level lighter than they were when the level was high. These are the reasons you see some folks recommend keeping the powder level low and just adding to it constantly to improve consistency.
What the baffles do is handle that task automatically. They do this by holding back most of the powder column weight above them, and they limit vibration effect by making the powder move down and then sideways to get to the metering chamber, which breaks some of the packing up. Adding a baffle can cut variations in half pretty easily, and two of them in tandem is like adding another layer of filtering to the charge weight noise. Just keep them at right angles so both layers of powder under them have to flow sideways.
Re, your scale. There is a fellow who tunes balance beam scales. Used to charge $20. Roughly triples the sensitivity and repeatability. Scott something. You can search him out on You Tube. But the main thing is to get one of those circular plastic bubble levels from Lowe's and get the thing leveled and on a steady, vibration-free surface. Keep static electricity and drafts away from it. If need bu, disassemble and clean and make sure no iron filings have got into the gap between the damping magnets and make sure the knife edge and the notches that set on it are clean and free of oil.