adjusting scale
- Thread starter cptjack
- Start date
You need to use a fixed weight of known value, then adjust the scale to read correctly. Do not adjust the weight in the pan to match what the scale reads. you need a reliable reference weight. Otherwise its just guesswork, and one doesn't want to guess on powder charge weights. EVER.
If you are using one of the balance beam type scales, it could need adjustment anytime it gets moved.
If you are using one of the balance beam type scales, it could need adjustment anytime it gets moved.
Marco Califo
New member
Are we talking about a Beam scale or an electronic scale?
Altitude variations of 800 ft is just above nil and does not change.
If a Beam scale it should have a screw base leg or knob which let's you adjust for your work surface not being level.
A good electronic scale will have an OEM procedure for calibrating itself.
FYI Denver is about 5000 ft elevation. Someplaces in the USA are below sea-level (for example, the Oakland-Alameda County stadium playing surface is 20' below).
Check weights will help you prove a scales accuracy to YOU (or not).
Altitude variations of 800 ft is just above nil and does not change.
If a Beam scale it should have a screw base leg or knob which let's you adjust for your work surface not being level.
A good electronic scale will have an OEM procedure for calibrating itself.
FYI Denver is about 5000 ft elevation. Someplaces in the USA are below sea-level (for example, the Oakland-Alameda County stadium playing surface is 20' below).
Check weights will help you prove a scales accuracy to YOU (or not).
As said above, unless you moved to Mars, or the Moon, or reloading on the space station orbiting the Earth ... Gravity change here on Earth will stay the same where-ever you set your scale at the macro measurements we are using anyway. Don't they teach that any more in school? 
. Ha. Actually thinking about it, I think it doesn't matter even on Moon/Mars as the 'force' acting on the scale and the weight is going to be the same. Now on the Space Station the force is ~zero so ... not a good place to reload in the conventional manner!
Gravity Difference Earth
Just make sure the beam is 'level' on the desk with no weight, and then use a check weight to verify it is reading correctly. My balance beam scale has not 'changed' since I bought it back in the early 80s.
. Ha. Actually thinking about it, I think it doesn't matter even on Moon/Mars as the 'force' acting on the scale and the weight is going to be the same. Now on the Space Station the force is ~zero so ... not a good place to reload in the conventional manner!Gravity Difference Earth
Just make sure the beam is 'level' on the desk with no weight, and then use a check weight to verify it is reading correctly. My balance beam scale has not 'changed' since I bought it back in the early 80s.
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I have used a RCBS digital scale for the last 30 years. I tare the pan to zero and it reads 140gr. Occasionally I’ve noticed it jumps to 141 when I remove the pan, signaling me to re-zero to 140.
I have 2 sets of weights from my Pharmacy career: apothecary and Metric. I can’t imagine one would have any weights more accurate than those we used to produce pharmaceutical products at a retail level. They were/are manufactured by Henry Troemner, Inc., from Philadelphia, PA., and were a part of my college admission purchase requirement in 1960.
Based on 1.0 Gm = 15.432 grains, this is what I would expect my 20- and 50-gram weights supplied with the RCBS scale to produce:
20 Gm = 308.64 grains. My scale says 308.1 and 19.98 Gm.
50Gm = 771.6 grains. My scale says 770.8 grains and 49.95 Gm
With the Apothecary weights, it becomes more accurate:
Set for “grains” I get the following results:
5 grains weight = 5.0 grains
2 grains = 2.0
1 grain = 1.0
0.5 grain = 0.5
One Scruple ( apothecary) = 20 grains. My scale delivers 19.9 grains.
If I set the tared schedule to “Grams” and 0.000., I get
500mg = 0.5 Gm
200mg = 0.20Gm
100mg = 0.9 Gm
50mg = 0.04 Gm that instantly converts to 0.00
20mg = 0.02Gm that again, instantly flips to 0.00
10mg =0.00 = no reading
So it would appear that my RCBS scale is more accurate in the grain mode, and that explains to discrepancy with the weights supplied in grams. However, in practice, as I said above, I find that the tared (zero) weight of 140 occasionally jumps to 141. This means my tared pan weight has increased by 1.0 grain, so if my target weight is 50 gr, that particular load only has 49 gr. I have never experienced the opposite situation, i..e, an increase in the charge due to a decrease in the tared pan weight.
So any time I remove the pan to dump the charge, I observe the tared weight of 140. Then I am assured my measured weight is the one desired. If the tared pan jumps to 141, I reset it to zero again, and re-weigh that charge.
I will say, this change is not common; I do not have any significant drafts in my area of reloading and I do have a surge protector plugged into the receptacle, followed by my plug for the weight scale.
I have 2 sets of weights from my Pharmacy career: apothecary and Metric. I can’t imagine one would have any weights more accurate than those we used to produce pharmaceutical products at a retail level. They were/are manufactured by Henry Troemner, Inc., from Philadelphia, PA., and were a part of my college admission purchase requirement in 1960.
Based on 1.0 Gm = 15.432 grains, this is what I would expect my 20- and 50-gram weights supplied with the RCBS scale to produce:
20 Gm = 308.64 grains. My scale says 308.1 and 19.98 Gm.
50Gm = 771.6 grains. My scale says 770.8 grains and 49.95 Gm
With the Apothecary weights, it becomes more accurate:
Set for “grains” I get the following results:
5 grains weight = 5.0 grains
2 grains = 2.0
1 grain = 1.0
0.5 grain = 0.5
One Scruple ( apothecary) = 20 grains. My scale delivers 19.9 grains.
If I set the tared schedule to “Grams” and 0.000., I get
500mg = 0.5 Gm
200mg = 0.20Gm
100mg = 0.9 Gm
50mg = 0.04 Gm that instantly converts to 0.00
20mg = 0.02Gm that again, instantly flips to 0.00
10mg =0.00 = no reading
So it would appear that my RCBS scale is more accurate in the grain mode, and that explains to discrepancy with the weights supplied in grams. However, in practice, as I said above, I find that the tared (zero) weight of 140 occasionally jumps to 141. This means my tared pan weight has increased by 1.0 grain, so if my target weight is 50 gr, that particular load only has 49 gr. I have never experienced the opposite situation, i..e, an increase in the charge due to a decrease in the tared pan weight.
So any time I remove the pan to dump the charge, I observe the tared weight of 140. Then I am assured my measured weight is the one desired. If the tared pan jumps to 141, I reset it to zero again, and re-weigh that charge.
I will say, this change is not common; I do not have any significant drafts in my area of reloading and I do have a surge protector plugged into the receptacle, followed by my plug for the weight scale.
No. I moved from 162' elevation to 3740' elevation and it had no effect on my RCBS "10-10" scale.
I didn't read every line of every reply. But if not already mentioned, make sure the platform your scale is sitting on is level. Not just left-to-right, but also front-to-back.
I recommend check weights. I use check weights with every load session.
Optional "geek out" reading: A balance scale will read the same on the moon as it does on earth. But the moon, with 1/6th the gravity, will cause the beam to deflect only 1/6th as much. In other words, it will only have 1/6th the resolution; but, it will still balance with the same mass.
Captjack,
Gravity varies with latitude and with how dense the material under your feet is. However, within the continental US, you can expect that in the Rocky Mountains, the error would raise the weight of 100 grains to about 100.003 grains as compared to their weight in Ohio. To measure that, you'd need a lab scale calibrated in Ohio and dragged up on top of the Rocky Mountains without touching the calibration. So it's not a lot within the continental U.S. And, if you recalibrate the scale at your use locations, even that error goes away.
With a true balance, though, you are comparing masses (the mass you are measuring and the masses that slide along the counterpoise) and not weight, so it won't go out of calibration at all, regardless of gravity. In that instance, a shift is more likely to be dust or oil or something having got onto the knife edges and stiffened with a drop in temperature, or else the knife edges have been chipped or damaged in carrying the scale up the mountain.
Gravity varies with latitude and with how dense the material under your feet is. However, within the continental US, you can expect that in the Rocky Mountains, the error would raise the weight of 100 grains to about 100.003 grains as compared to their weight in Ohio. To measure that, you'd need a lab scale calibrated in Ohio and dragged up on top of the Rocky Mountains without touching the calibration. So it's not a lot within the continental U.S. And, if you recalibrate the scale at your use locations, even that error goes away.
With a true balance, though, you are comparing masses (the mass you are measuring and the masses that slide along the counterpoise) and not weight, so it won't go out of calibration at all, regardless of gravity. In that instance, a shift is more likely to be dust or oil or something having got onto the knife edges and stiffened with a drop in temperature, or else the knife edges have been chipped or damaged in carrying the scale up the mountain.
RC20, yes, it measures the powder weight in tenths, but when zeroed, the empty pan is just 140. After reading this, I went to the reloading room and compared two pans; one plastic and one metal. I zeroed the scale with no pan on it, then weighed each pan. Then I alternated zeroing each and weighing each. I cannot explain these results:
No pan = 00.0
Empty metal pan weighs 140.4
Empty plastic pan weighs 99.1
Zeroed plastic pan = 00.0
Removed the pan = -99.2 (ok so far)
Weighed the empty metal pan = -41.3 (? should be 140.4)
Removed the empty metal pan = -99.2 (ok)
Zeroed the empty metal pan = 00.0
Removed the metal pan = 140 (as usual)
Weighed the empty plastic pan = -41.2 (? should be 99.2)
Go figure. I can't explain it. I need a drink.
No pan = 00.0
Empty metal pan weighs 140.4
Empty plastic pan weighs 99.1
Zeroed plastic pan = 00.0
Removed the pan = -99.2 (ok so far)
Weighed the empty metal pan = -41.3 (? should be 140.4)
Removed the empty metal pan = -99.2 (ok)
Zeroed the empty metal pan = 00.0
Removed the metal pan = 140 (as usual)
Weighed the empty plastic pan = -41.2 (? should be 99.2)
Go figure. I can't explain it. I need a drink.
Skipped the drink. For now. Got my Troemner Apothecary weights and used forceps to add and remove the weights so body oil would not be added to the weight.
Plastic pan tared to zero, leave tared weight -99.2
1 Scruple = 20.0 gr - weighed 19.9gr
1/2 " = 10.0gr = 10.0 gr
5.0 gr = 5.0 gr
4.0gr = 4.0 gr
3.0gr = 3.0 gr
2.0 gr = 2.0 gr
1.0 gr = 1.0 gr
0.5 gr = 0.5 gr
Tared metal pan to 00.0
Removed pan = -140 (as usual)
All the above weights came out the same, including 19.9 gr with the 1 Scruple.
I did not have a weight less than 0.5 gr, so I can't determine if the sensitivity is lower than 0.5gr. But I do know if I want 78.0 gr of powder and it stops at 77.8 or 77.9, I can trickle it to 78.0. If I add a bit too much I can get 78.1, 78.2, etc.
So I no longer need that drink. But guess what? Need and desire.....
Plastic pan tared to zero, leave tared weight -99.2
1 Scruple = 20.0 gr - weighed 19.9gr
1/2 " = 10.0gr = 10.0 gr
5.0 gr = 5.0 gr
4.0gr = 4.0 gr
3.0gr = 3.0 gr
2.0 gr = 2.0 gr
1.0 gr = 1.0 gr
0.5 gr = 0.5 gr
Tared metal pan to 00.0
Removed pan = -140 (as usual)
All the above weights came out the same, including 19.9 gr with the 1 Scruple.
I did not have a weight less than 0.5 gr, so I can't determine if the sensitivity is lower than 0.5gr. But I do know if I want 78.0 gr of powder and it stops at 77.8 or 77.9, I can trickle it to 78.0. If I add a bit too much I can get 78.1, 78.2, etc.
So I no longer need that drink. But guess what? Need and desire.....
No, should be +41.3 because the scale is tared at -99.1 and 140 is 41.3 grains bigger than that.
Should be -140.0.
This is correct because the scale is tared on -140, so the 99.2-grain pan can't bring it all the way up to zero, leaving it at -41.3 (it is off by one LSB at -41.2, but so what?).
Thanks, Unclenick, that clarifies why my Apothecary weights delivered the results as expected. It also clarifies that all men may be created equal with the expectation of having the opportunity to excel but not in all endeavors that exist. That's why these forums are so valuable, and the unrewarded exchange of information should be a lesson to the politicians who are screwing up the country. Sorry for the diversion.
Good move. My hands have never touched my check weights. Always with tweezers. And I'm usually wearing gloves (my hands oxidize everything they touch, it's weird), but that doesn't matter - tweezers, always.
FWIW, I use check weights for every load session. For instance, if I'm going to load with a charge weight of 8.7 grains, I'll first set the scale to 8.5 grains, and make sure it's at perfect balance with 8.5 grains of check weights. Then gently move it to 8.7.