Balance scale giving incorrect weights

Another oldie but goodie for calibrating or checking calibration on a scale:

New quarters from the United States Mint are an option; a brand new U.S. quarter has a mass of 5.670 grams. Other options are brand new U.S. pennies or nickels; a penny has a mass of exactly 2.500 grams, and a nickel has a mass of 5.000 grams.

Place your chosen coin on the scale and read the output. If you placed a penny on the scale, you should read 2.500 grams. If you place a quarter on the scale, the output should read 5.670 grams.

If the scale read 5.671 grams, clearly there is a 0.001 gram difference in the reading and the known mass. Thus, you have also determined that any calibration error will likely be around 10-3 grams, meaning that the scale is fairly accurate for tenths and hundredths.

If the reading for the penny was 2.500, but the reading for the quarter was was 5.700 grams, you can see that the scale only has the resolution to measure a tenth of a gram. This is yet another form of calibration.
 
Any chance you can post a picture of the scale? One of my older scales (Redding, I think) has some calibration adjustment built in.
 
Your question made me curious? Your scale is likely fine. 10 nickles from various years, weighed on the same scale. Take note of 2006 & 2020,,, 2 pairs from same years with different weight.
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A Million years ago I was in the Electronic scale business for a short while. I learned a thing. That is ,In a Balance Beam type scale, the V shaped blade under the beam rides in a piece of Agate ( spelling ) that is notched to the shape of the V blade under the beam. I was taught that the worst thing you could do a scale like that was to slide it on you bench ,or push it away when your all done with it. The blade under the beam bounces the the Agate stone and causes Micro Chips in the stone, and accuracy diminishes the more you do that. So after 10 or 15 years of using the scale, and sliding it out of the way on your bench, the blade , and the Agate stone are no longer perfect as the where when they were new. Maybe an old scale company , or the manufacture can replace the stone. The next time you get one be very gentler with it. IMHO
 
A Million years ago I was in the Electronic scale business for a short while. I learned a thing. That is ,In a Balance Beam type scale, the V shaped blade under the beam rides in a piece of Agate ( spelling ) that is notched to the shape of the V blade under the beam. I was taught that the worst thing you could do a scale like that was to slide it on you bench ,or push it away when your all done with it. The blade under the beam bounces the the Agate stone and causes Micro Chips in the stone, and accuracy diminishes the more you do that. So after 10 or 15 years of using the scale, and sliding it out of the way on your bench, the blade , and the Agate stone are no longer perfect as the where when they were new. Maybe an old scale company , or the manufacture can replace the stone. The next time you get one be very gentler with it. IMHO
That's interesting, I never heard that before. Thanks for the tip!
 
Any idea how to fix a balance scale that is throwing incorrect weight? I double checked it with an electronic scale and another balance scale. A nickel weighs 77.2 grains but my Reading balance scale is about .3 grains light, readying 76.9.
Give the whole scale a good cleaning and recheck it. I have an RCBS that is several tenths off from my other scales. I use IT only for powder measureing and no other. Like the loading manuals it is a referance as no two show the same load as max. and can only be used as a referance point too load from. When you work up a load the weapon likes and it is with that scale it is a point you can repeat. But only with that scale! The numbers aren't as important as the ability too repeat them.
 
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