Checking Digital Scale Accuracy


PDA






trapper500
April 25, 2011, 08:16 AM
do any of you guys that use a digital scale have a back up scale to check you digital scale to insure their weighing correctly iam jsut wondering let me know

If you enjoyed reading about "Checking Digital Scale Accuracy" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!
bds
April 25, 2011, 08:31 AM
I always recommend a beam scale first (like RCBS 5-0-5 or Dillon Eliminator) then a digital scale for faster readings but to have the digital scale checked against the beam scale. Also use check weights to verify the readings on both scales.

I use a FA DS-750 digital scale but it gets checked with Ohaus 10-10 scale. After calibration/zero and verification with the check weights, when I get the same readings on both scales (with acceptable variation of .1 gr from the digital scale), I then move on to use the digital scale for faster readings.

Wolfman Bill
April 25, 2011, 08:43 AM
Morning trapper500

As a rule I don’t cross check the digital to a beam scale but I do check the digital using a “test” weight that is close to the load I am going to weigh. I have test weights I have made up from about anything from a small rubber cap to some ground down bullets that are 5, 10, 15, 20, 25, 30, 35, 40, 45, 50 grains. SO, if I am weighing a 23 gr charge I will check the digital using a 20 or 25 gr test weight before using it to weigh a series of charges.

ranger335v
April 25, 2011, 09:46 AM
I don't/won't have a tool that suggests the desireability for another tool to make sure the first tool is working. That especially includes digital powder scales.

Smokey Joe
April 25, 2011, 12:07 PM
ANY measuring tool needs to be √'ed once in a while, to be certain that it has not lost accuracy or needs recalibration.

Beam scales have their place. Digital scales have their place. So do calipers and micrometers and throat erosion gauges, etc, etc, etc.

For weighing devices, that's why there are check weights. You get yourself a set and they are good for life--careful not to lose the bitsy ones!

What's the big deal?

higgite
April 25, 2011, 12:47 PM
What Smokey Joe said.

MEHavey
April 25, 2011, 12:51 PM
Before I start a loading session, I run a couple of checkweights at/near the load I'll be using -- sometimes I just use a single 223 match bullet that I keep in the "checkweight" box.

As I proceed w/loading, I check that the scale displays the same "negative weight" when the powder pan is removed -- and then goes back to '0.0' cleanly when the empty pan is replaced. Cycling on these before-&-after weights keeps a continuous track of the scale's consistancy during that particular session.

ColtPythonElite
April 25, 2011, 02:10 PM
Before a loading session, I always calibrate my scale with the check weights even if it measures them correctly...Every now and then during the loading session, I put on a check weight just to verify the scale is still calibrated correctly.

snuffy
April 25, 2011, 02:17 PM
http://www.midwayusa.com/viewProduct/default.aspx?productNumber=212586

Use of this check weight set will answer any questions about if your scale is weighing correctly and is calibrated. Using something cobbled up to weigh what you want it to weigh is not the answer. You have to have standards that an accurate scale in a lab has set. If you were to buy a lab scale you'd better have a pile of money.

Don't think that the calibration weights supplied with an electronic/digital scale are check weights. Although knowing what they actually weight isn't a bad thing. They're far too big and heavy for seeing if your 2.5 or 5 grain check weights register as they should. The above set will total out at 60.5 grains. There's others on this page;

http://www.midwayusa.com/browse/BrowseProducts.aspx?pageNum=1&tabId=1&categoryId=19937&categoryString=9315***731***9211***19935***

1858
April 25, 2011, 07:18 PM
If you were to buy a lab scale you'd better have a pile of money.

No kidding!! We have a Metler balance at work that is a $10,000 unit. It used it to measure the Lyman check weights from the set below and was very impressed with the accuracy.

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=612694

I typically check my CM 1500 by bracketing the desired weight(s) with Lyman weights. I don't even calibrate the CM 1500 these days. I turn it on about 30 minutes before I need to use it, bracket to check and that's it.

cfullgraf
April 26, 2011, 05:45 PM
Before a loading session, I always calibrate my scale with the check weights even if it measures them correctly.

I agree. I calibrate my electronic scale at the start of each session. Once calibrated, I do not turn the scale off or move it.

I zero the scale frequently, maybe every third or so charge.

Electronic scales need a relatively vibration free base to sit on. Vibration and wind can affect the scale's reading.

GW Staar
April 26, 2011, 06:19 PM
With Electronic scales there are other gotta's, you need to be aware of.

Cheap scales especially, may weigh the check weights perfectly at first, on calibration, and yet in a few minutes be off. They are effected by temperature (and warm-up time), magnetic fields in Fluorescent lights close by, battery condition, or if plugged in, electrical brownouts, spikes, and surges. (Use fresh batteries and/or a quality line conditioner)

Even the most expensive electronic is limited by electronic circuits that can change, even die over time. Anyone know of a computer or TV that lasts more than a few years?

I think good electronic scales are wonderful for speeding things up....but don't expect them to last as long as a good, well taken care of, Ohaus beam scale. Won't happen.

I think a backup to ANY electronic scale is crucial: I use and trust my check weights and my 40 year old Ohaus/RCBS 10-10 scale.

snuffy
April 26, 2011, 08:34 PM
I think good electronic scales are wonderful for speeding things up....but don't expect them to last as long as a good, well taken care of, Ohaus beam scale. Won't happen.

Well then, my RCBS powder pro I bought back in '98 shouldn't still be working AND be accurate as checked by my Lyman check weights.

If you buy a name brand scale and take care of it, you'll get good long service. That scale was made by PACT, I expect it to keep on working.

wingman
April 26, 2011, 09:28 PM
I use a Lyman balance beam and a RCBS 750 digital, at beginning of a reloading session I calibrate both and during reloading (using the digital)I cross check on occasion with the balance beam if anything seems out of place I recheck my loads, time consuming for sure but my rifle shooting is for targets and precision so to me its worth the effort.

Hondo 60
April 26, 2011, 09:38 PM
I have 2 digital & 1 beam scale.
(bought the 2nd digital cuz I had to send the first one in for repair)

Plus I have check weights.

So I guess I have redundant redundancy.

GW Staar
April 26, 2011, 09:53 PM
Well then, my RCBS powder pro I bought back in '98 shouldn't still be working AND be accurate as checked by my Lyman check weights.

If you buy a name brand scale and take care of it, you'll get good long service. That scale was made by PACT, I expect it to keep on working.

Congratulations! 13 years...pretty impressive...for an electronic. I won't be here in 27 years (I hope), so I can't have a friendly wager with you to see if it will last as long as my already 40 year old beam scale.....but I'm just saying that if you used it as much as you do your computer or TV, you'd probably be looking for a new one already. What I'm not saying is that I wouldn't have one...because I do....the convenience is worth the risk. I also check it often to make sure its still true.

I admit that my first electronic scale was a $30 one.....not quite the same as a Powder Pro...;) It, btw, was not worth turning on...I upgraded of course. I still use the 10-10 on hot loads (just feel safer) and as a double check for the faster electronic.

EddieNFL
April 26, 2011, 10:32 PM
I don't/won't have a tool that suggests the desireability for another tool to make sure the first tool is working. That especially includes digital powder scales.
That eliminates lots of things from your life.

bds
April 26, 2011, 10:39 PM
Checking Digital Scale Accuracy
do any of you guys that use a digital scale have a back up scale to check you digital scale to insure their weighing correctly i am just wondering let me know
I thought the OP was about "checking digital scale accuracy" and how we ensure they are weighing accurately ... :rolleyes:

trapper500
April 27, 2011, 05:58 AM
hey i thank all of you fellas for your posts

SSN Vet
May 11, 2011, 04:22 PM
Just a funny anecdote about scales for you....

We have a lab. scale at work (a $500 model, not a $10,000 model).

So me being the frugal Fanny that I am, I label coins and paper clips and use them as check weights for my Lee Safety Scale at home.

When simply zeroed on an empty pan, that cheasy little Lee scale has always matched the lab. scale check weight measurements exactly (vernier on the Lee scale reads to 1/10th of a grain).

Not to shabby for $20.

Of course I'll probably go blind reading that silly vernier, but I do trust it.

helotaxi
May 11, 2011, 07:33 PM
My take is as long as it's consistent and initially at least in the ballpark, dead-on-balls-accurate isn't needed. If you work up loads on your equipment, and the scale is consistent, what does it really matter if it is off a half grain from the exact charge weight? It's off that same half grain every time and working up the load accounts for the inaccuracy. Precision and repeatability is more important, IMO.

Hondo 60
May 11, 2011, 09:15 PM
I use the check weights that came with the scale

bds
May 11, 2011, 10:37 PM
If you work up loads on your equipment, and the scale is consistent, what does it really matter if it is off a half grain from the exact charge weight?
I guess if you are half grain under, you might be OK but if you are half grain over with powders like Titegroup with very narrow load range (often half grain from start to max), you will be doing your work up from the max charge.

I would like to quote Morpheus from the movie Matrix.

Morpheus talking to Neo: "Do you think that's air you're breathing now?"

When I was being taught to reload, I was told that assumption is the mother of all "mess ups". I was told to verify everything and double check everything, EVEN when I was sure as we are humans with poor memory and WILL make mistakes and not even know that we are making them. How many of us seasoned reloaders mixed up components such as bullet type/weight, powders and load data and was SURE we double checked it? I have and will admit that fact to benefit other new reloaders who have not experienced the unfortunate results of such mistakes (luckly, the overcharge just shattered my pride and not my body parts :eek::D).

To me, the objective of reloading is the careful orchestration of controlling multiple variables to arrive at a precise combination of components to produce consistency in chamber pressure based on verified "knowns" to produce accuracy safely.

helotaxi
May 11, 2011, 11:32 PM
I guess if you are half grain under, you might be OK but if you are half grain over with powders like Titegroup with very narrow load range (often half grain from start to max), you will be doing your work up from the max charge.
I don't load anything nearly that sensitive. Everything I load has more than 1gn of spread between min and max according to Hornady and wider according to others with Titegroup (which I don't use a lot of). Also 0.5gn was an example to make a point, I'm quite sure that my digital scale is much closer than that and has proven perfectly consistent.

What is ridiculous to me is using both a beam scale and check weights to verify a digital scale. If you have check weights, the beam scale is pointless. The beam scale would need to be checked and calibrated as well so why bother. Check weights are all that is required if being spot on is that important to you since that's what would be used to verify the beam scale. Adding another verification device would actually be considered less precise by an engineer because of tolerance stacking and calibration errors.

blarby
May 12, 2011, 07:30 AM
If you really need a good set of check weights, grab some coins...

You will find them more than adequate for 99% of your uses, and they literally cost less than a dollar.

snuffy
May 12, 2011, 10:30 AM
I use the check weights that came with the scale

Most digital scales come with 2 CALIBRATION weights, they are much too heavy to know if your scale is accurate weighing 0.5. or 1 grain. The whole idea of check weights is something that's been weighed and made in small increments ACCURATELY. Not some object YOU weighed on YOUR scale which could be up to 1.5 grains off. That induces error across the spectrum of the scale capacity.

If you really need a good set of check weights, grab some coins...

Again, they weigh what YOUR scale says they weigh! What do they really weigh? Sure, I know the gubmint SAYS they're supposed to weigh *.**, but how close do they check?

What some have done weighing objects on an expensive lab scale that's certified/calibrated often, then using them to check their scales, is one way. I don't know anyone that has a lab, do you?

My Lyman check weights work just fine, my RCBS powder pro checks out right on each time I check it. Spend the money, the peace of mind is priceless!

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=612694

blarby
May 13, 2011, 01:58 AM
The "gubmint" has a very vested interest in making sure they all way the same, actually.

Every one I have ever chosen to weigh has been within .5 grains unless it was really dirty, or altered.

If you had 3 of them, and they weighed out...you'd be in the clear.

If .5 grains isn't good enough...you are in that percentile I mentioned. Please purchase checkweights accordingly.

If you enjoyed reading about "Checking Digital Scale Accuracy" here in TheHighRoad.org archive, you'll LOVE our community. Come join TheHighRoad.org today for the full version!