Lost faith in my electronic scale today

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When consistently comparing multiple loads between my beam scale (on a shelf at eye level) with a sensitive digital, if I look close enough, hold my head exactly the same each time, and wait long enough, (Yawn,,,) I can see that fraction of a needles width difference on the Beam scale that my digital portrays in no uncertain terms in far less time.

I'll say that even with my trusty Lee Safety Scale, I can see the needle deflect from a single kernel of Varget/IMR 4064/etc. My digital on the other hand I can get 2-5 kernels on the tray before it will finally register. Admittedly I'm not usually worried about having a charge within .1 grains, but when I'm trying to find "THE" load, it certainly helps.

If Lee made a balance style "safety scale" that went over 100 grains I'd happily buy it.

If you can split your charge in half, you can use the safety scale still (ie you need 164.3 grains, 82.15 will get you there).
 
Have you tried what’s done in #19?
Not exactly. The scale does not give a reading below .5 gn. We learned about that during the electronic scale myth debunking test. Before this I had been able to count granules to go up 0.1 gn., and repeat over and over.

I was throwing charges of 7.3 gn. I was on the third case when I found the problem. The scale had stabilized at 0.0 between charges. I had dropped 7.5 gn. shook a few granules out of the pan and reweighed, showing 8.1 gn. When I reweighed the two I had just thrown one showed 4.5, the other 4.1. After recalibrating the results were similar, but not exactly the same. I'm guessing the sensor has gone bad.
 
What’s in there for the “sensor” is just a block of aluminum with a Wheatstone bridged attached for it.

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Would be pretty odd for one to “go bad” and still give readings that were not totally off the wall. They do interact with other components though and the problem could be in that interaction.

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I’d think those electronic scale could be affected by humidity, dust even atmospheric pressure. I have one, a Hornady , a gift, don’t trust it, jumps around too much.
 
Four months with my Chargemaster and so far I love it. I check it often with either my Dillon or RCBS beam and so far it has been spot on.
I think Jesse Heywood has good reloading practices and was able to figure out something was wrong quickly. He had 10 good years with it which I think is pretty good for any electronic device.
 
Check weights and use them. Plus watch the display when the pan is removed and when you replace an empty pan. I trust my Pact Precision (20 plus years old) my Gempro 250 and Chargemaster Lite. The Gempro 250 is so touchy and takes a little longer to settle down when trickling powder. I've compared them all with the same weights moving the powder pan from one to the other and all agree to less than 1/10 grain. Have confidence in all 3 and my RCBS 5-10 sits in a drawer. I trust it less trying to eye the pointer.
 
Took it apart and cleaned out the powder dust. Appears to be working correctly. Will check with better weights and against another scale when it arrives.
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Stopped and made breakfast. When I came back to the basement the results were the same. So I ordered a new Gemini scale and a set of weights. So my loading session is on hold until the UPS (or USPS) man delivers in a couple more days.
Is this the Gemini you ordered? https://www.amazon.com/American-Weigh-GEMINI-20-Portable-MilliGram/dp/B0012TDNAM
This has been as accurate as my Gem Pro 250 which cost ten times more. The Gemini 20 is dead-nuts-on with my Ohaus check weights. The pan is small as is the whole scale but it's easy to read with the backlit display. I paid $21 for mine since the price fluctuates. It's a good back-up scale.
 
Took apart my CM1500 yesterday to clean it. I had ball powder (TAC) all over the beam. This a very different setup for what I normally see with load cells. They have fulcrum off to the side of the beam vs in the middle. When I put it back together I had a zero that was drifting badly. Took it apart again made sure I had the pan support centered and tightened the 2 screws down, tested. No zero drift. Put it back together and calibrated it. Working like a champ now. Did discover that the 50gr calibration weight that sits on the back left effects the zero. If I remove it, the zero shifts 0.2gr. Put it back and goes back to zero. Does not effect the calibration though. Just something to be aware of when your calibrating the scale. Calibration Weights appear to be Brass, non magnetic. I did intensive testing with my check weight to confirm it was working right. There is a internal switch on the mother board for Adj/Lock and a 6 pin connector jack to plug into.

CM1500 load cell.jpeg CM1500 Motherboard.jpeg
 
I bought the Gemini 20, which will take some getting used to. And a set of weights from 1 to 20 grams, which I had needed. The RM 750 came with a 20 & 30 gram for calibration, and were all that I had used. After a second recalibration, the RM is working fine. Hard to believe that some powder dust that filtered between the tray support and the aluminum lever could have been the problem. But we live and learn.

Now I know why the nun in analytical chem had the precision scales, both beam and the new digitals, in an unventilated room with a darkroom light, covered and inside glass cases. In 1970.
 
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