Let's talk mechanical/beam scales for a minute

[rpenmanparker]

That's exactly what I did with my Dillon scale. I had a number of lead bullets someone gave me that I really didn't plan to load. I used a large bottle of super glue and carefully stacked them in the inverted base. Let them dry for 24 hours, then lay the next layer. It probably weighs 4 lbs now and is very stable.

Another method would be to use lead bullets as aggregate in some plaster of Paris or cement and fill the space with that. Scrape off the bottom flat for a solid base.

 

[Zaydok Allen]

Interesting. The most demanding scientific studies are performed exclusively with electronic balances/scales very commonly to 0.1 mg (0001 g). Have been since about 1970. In science mechanical scales are curiosities on the mantlepiece. I highly doubt that any of the factors you cite interfere with the accuracy and precision of electronic ones.

Well most of us are not reloading in a lab. We are reloading in a home that has commercial wiring, and some of that wiring is old. Some commercial electronic items that we keep in our homes throw off surprising amounts of EMFs. An EMF detector can be purchased by anyone to find that out.

And most people aren't dropping several hundred or several thousand dollars on scales that may have better shielding. Many folks are buying $50 scales that don't take a lot to through them off.

To assert that you doubt that electronic scales can be thrown off by environmental factors based on the scientific community's use of electronic scales is baseless. You very well may be right, but you have no information or data presented here to back that up.

How many different commercial electronic scales have you tried out?

 

[rpenmanparker]

Well most of us are not reloading in a lab. We are reloading in a home that has commercial wiring, and some of that wiring is old. Some commercial electronic items that we keep in our homes throw off surprising amounts of EMFs. An EMF detector can be purchased by anyone to find that out.

And most people aren't dropping several hundred or several thousand dollars on scales that may have better shielding. Many folks are buying $50 scales that don't take a lot to through them off.

To assert that you doubt that electronic scales can be thrown off by environmental factors based on the scientific community's use of electronic scales is baseless. You very well may be right, but you have no information or data presented here to back that up.

How many different commercial electronic scales have you tried out?

I think you got the wrong impression from my post. First of all I have been using electronic balances/scales almost since they were invented, back to 1966 at least. Mettler at first and then Ohaus and too many different brands and models to remember them all. I managed analytical chemistry labs for years and also corporate analytical networks of representatives and functions of all the labs in the company related to a specific group of products. We are talking about a Fortune 5 enterprise. Not 500, but 5.

So I know something about electronic weighing. I know about using bases protected against vibration, directing air flows away from the weighing stations, isolating the electrical connection from variations, closing enclosures of 0.1 mg balances.

But what I also know is that at the next coarser level of precision, 1 mg, all those protections simply don’t matter. At 1 mg precision you just don’t have to worry about all that stuff. That is somewhere between 0.1 gr and 0.01 gr.

 

[fotheringill]

Redding #2 is made of whatever metal is used and then painted green. It is sturdy and is sensitive to a kernel of Varget or less. No air current or shaking in the weighing area. I have repeatedly checked the weight against a relatively inexpensive battery scale and there are no errors. They match exactly.

 

[cougar1717]

I admit I didn't read the previous thread concerning the OP's fluctuating scale. So I don't know what that problem was other than it was untrustworthy. It is true that temperature, emf, and air circulation affect most of our budget friendly reloading scales and that an actual science lab wouldn't consider our reloading scales worth using. Most of the time, reloaders attempt to reduce the issues by trying to keep the area temp stable, HVAC diffusers not directly over a scale, calibrate with check weights before each use, etc. This usually works.

If you've tried to mitigate it and either don't trust your electronic scale or just want to double check it with a balance scale, then...

This is my opinion -

If you don't trust your electronic scale, the first question would be: Is it a reasonable quality scale? As in, Did it cost about $100 or more? The super cheap scales (under $50) are usually not that reliable and fluctuate and just frustrate the user. If you have a $35 scale that has worked 100% for you, congratulations. It's just that you usually get what you pay for with those.

If it's a reasonable quality electronic scale: Do you have check weights to calibrate each use? These can also be used to confirm a fluctuation. At least you know your check weight didn't change if you think the errors are stacking.
If you have no idea why the scale is doing what it is doing and have tried everything short of returning it to the manufacturer, then...

Check it against a beam.
Remember that beam scales are slow. You're not using them to weigh every charge since that would take forever. You are using it to check your powder measure drops. I'd suggest checking with ball powder as it fills the powder measure cylinder more completely than extruded for more consistent drops, but that is up to you.

The Lee Safety is inexpensive and accurate, but not the easiest to use. The vernier is not terrible, but let's face it, it's inexpensive and it just barely works. What do you expect for 20-some dollars? - it's a safety scale, not a high production scale. But it will work.
The scales that are made in the same pattern as the RCBS Ohaus scales are usually more expensive, higher quality, and generally easier to use. Everyone recommends these because they are made well, have an adjustable foot, and can be calibrated easier.
But like anything, it's imperative to calibrate it to zero and check it with items of known weight and make sure you're looking on an even plane with the beam scale (not reading the measurements from an angle).

Lastly, this has been answered, but these scales do measure in grains - no conversion needed from grams.

 

[rpenmanparker]

I admit I didn't read the previous thread concerning the OP's fluctuating scale. So I don't know what that problem was other than it was untrustworthy. It is true that temperature, emf, and air circulation affect most of our budget friendly reloading scales and that an actual science lab wouldn't consider our reloading scales worth using. Most of the time, reloaders attempt to reduce the issues by trying to keep the area temp stable, HVAC diffusers not directly over a scale, calibrate with check weights before each use, etc. This usually works.

If you've tried to mitigate it and either don't trust your electronic scale or just want to double check it with a balance scale, then...

This is my opinion -

If you don't trust your electronic scale, the first question would be: Is it a reasonable quality scale? As in, Did it cost about $100 or more? The super cheap scales (under $50) are usually not that reliable and fluctuate and just frustrate the user. If you have a $35 scale that has worked 100% for you, congratulations. It's just that you usually get what you pay for with those.

If it's a reasonable quality electronic scale: Do you have check weights to calibrate each use? These can also be used to confirm a fluctuation. At least you know your check weight didn't change if you think the errors are stacking.
If you have no idea why the scale is doing what it is doing and have tried everything short of returning it to the manufacturer, then...

Check it against a beam.
Remember that beam scales are slow. You're not using them to weigh every charge since that would take forever. You are using it to check your powder measure drops. I'd suggest checking with ball powder as it fills the powder measure cylinder more completely than extruded for more consistent drops, but that is up to you.

The Lee Safety is inexpensive and accurate, but not the easiest to use. The vernier is not terrible, but let's face it, it's inexpensive and it just barely works. What do you expect for 20-some dollars? - it's a safety scale, not a high production scale. But it will work.
The scales that are made in the same pattern as the RCBS Ohaus scales are usually more expensive, higher quality, and generally easier to use. Everyone recommends these because they are made well, have an adjustable foot, and can be calibrated easier.
But like anything, it's imperative to calibrate it to zero and check it with items of known weight and make sure you're looking on an even plane with the beam scale (not reading the measurements from an angle).

Lastly, this has been answered, but these scales do measure in grains - no conversion needed from grams.

Why do you think an inexpensive mechanical scale can check an inexpensive electronic scale any better than another inexpensive electronic scale? Just because you can see the workings of the mechanical scale and touch and feel them, doesn’t make it any more reliable than the electronic scale. And do you have the necessary statistical understanding to know whether two results from different scales are statistically the same or significantly different? And if they are significantly different, which one is right, and which one is wrong? Now weighing standard weights on the scale you are questioning is a different story. That makes sense. In short the “check” beam scale is a waste of your time and money.

 

[LiveLife]

electronic scale ... Did it cost about $100 or more? The super cheap scales (under $50) are usually not that reliable and fluctuate and just frustrate the user.

We busted this myth long time ago. Let's not perpetuate the myth - https://www.thehighroad.org/index.php?threads/revisited-myth-busting-digital-scales.821449/

In the "Mythbusting Digital Scale" thread, we busted the notion that cheap $20 digital scales were not accurate enough for reloading. We verified Frankford Arsenal DS-750 with .1 gr resolution was accurate within .1 gr to Ohaus 10-10 as verified by Ohaus ASTM Class 6 and Lyman/RCBS check weights and Gemini-20 with .02 gr resolution was more accurate than Ohaus 10-10 which has been used by match shooters for decades to win matches out to 1000 yards.

Digital scales have normal operating temperature range of around 59F - 95F. If they are used outside of "room temperature" range or have weak battery, they will act inconsistent/erratic. None of my digital scales have shown any issues with two CFL (now LED) goose neck lights mounted on my bench.

Recently, at the recommendation of many, I bought $19 WAOAW digital scale and while not as accurate as Gemini-20, certainly accurate enough for reloading - https://www.amazon.com/WAOAW-Millig...F8&qid=1528144438&sr=1-3&keywords=WAOAW+scale

Same scale for $17 - https://www.amazon.com/Homgeek-Mill...F8&qid=1528144438&sr=1-1&keywords=WAOAW+scale

Do you have check weights to calibrate each use? These can also be used to confirm a fluctuation.

+1. My Ohaus ASTM Class 6 check weights go down to .015 gr. While Ohaus 10-10 scale will detect .05 gr check weight along with WAOAW scale, Gemini-20 will detect down to .03 gr.

Check it against a beam ... The Lee Safety is inexpensive and accurate ... it will work.

+1. Lee Safety Scale will detect and repeat as consistently as two Ohaus 10-10 scales I have.

 

[Toprudder]

Well most of us are not reloading in a lab. We are reloading in a home that has commercial wiring, and some of that wiring is old. Some commercial electronic items that we keep in our homes throw off surprising amounts of EMFs. An EMF detector can be purchased by anyone to find that out.

I worked in the EMC (electro-magnetic compatibility) field for 21 years, in compliance test labs that tested home, commercial, and industrial products - everything from electronic cigarettes to open-pit mining loaders and dump trucks.

Different products have to meet different standards, depending on the intended environment, and the possible consequences of their use. Generally, the home environment is considered to be less harsh than industrial or commercial environments. In other words, products intended for home use are expected to have less RF emissions than products intended for the other environments, but they are also usually tested to lower levels for susceptibility to interference. Sometimes the standards and test levels a product is tested to is listed in the manual or accompanying documentation. You might find a statement for either FCC or CE compliance (most products today are tested to both) and also which class. Class A is considered commercial/light industrial, Class B is considered residential.

I have three different electronic scales that I use - A $300 RCBS Chargemaster, a Frankford Arsenal DS750, and a $25 Gemini-20. I have tested them all with everything in my shop turned on, including 5 overhead 4-tube fluorescent fixtures. The only thing that I found in my shop that interfered with anything was my Milwaukee Li-Ion battery charger, and it only interfered with my FM stereo - a quick addition of a ferrite bead to the power cable fixed that. None of my electronic scales were affected.

I often see people say to buy LED lights instead of fluorescent due to possible EMI. Just because it is LED doesn't mean it doesn't give off EMI. The LED powered by a DC power supply and simple current limiting resistor is very benign, and that is what most people think of when LED is mentioned, but LED light fixtures/bulbs have switch mode power supplies that can give off EMI much like computer power supplies, so don't think just because it is LED that it can't interfere. I've tested some LED fixtures from a very well known LED manufacturer that initially failed the emissions limits, and with fixes it just barely passed. A lot of companies that mass produce an item are interested in making their product just good enough to pass, and that is all.

I'm sure if you did an EMI audit of your house, you would find dozens, maybe hundreds, of devices that give off EMI - anything electronic - that does not necessarily mean they will interfere with anything. Any product sold today has probably been tested to some standard for immunity from interference, and to levels that can be expected in the intended environment. But, just because they passed some standard, that only means that you have a reasonable expectation that interference won't happen.

Having said all that, I know what the possibilities and consequences are with using electronic scales, and I use them anyway, even the cheap Gemini-20. But, that is just me. I do highly recommend a good set of check-weights, though, even for balance beams.

 

[cougar1717]

Why do you think an inexpensive mechanical scale can check an inexpensive electronic scale any better than another inexpensive electronic scale? Just because you can see the workings of the mechanical scale and touch and feel them, doesn’t make it any more reliable than the electronic scale. And do you have the necessary statistical understanding to know whether two results from different scales are statistically the same or significantly different? And if they are significantly different, which one is right, and which one is wrong? Now weighing standard weights on the scale you are questioning is a different story. That makes sense. In short the “check” beam scale is a waste of your time and money.

I'm sorry but I really don't understand this post. You are arguing against the basis of the OP's question - That he does not trust the fluctuations of his electronic scale due to unknown causes and wants a beam scale to check his electronic one.
If you disagree with his methodology, take it up with the OP. He didn't link the original thread that this assumption is based upon. I will leave the statistical argument of his methodology to you.

Some of you may recall the difficulty I had getting consistency from my powder measure, only to discover I was having trouble getting consistency from my electronic scale. The consensus of the group at that time was that I needed to be using a beam scale as the final arbiter of accuracy.

I'm about to order said beam scale.

 

[rpenmanparker]

I'm sorry but I really don't understand this post. You are arguing against the basis of the OP's question - That he does not trust the fluctuations of his electronic scale due to unknown causes and wants a beam scale to check his electronic one.
If you disagree with his methodology, take it up with the OP. He didn't link the original thread that this assumption is based upon. I will leave the statistical argument of his methodology to you.

Oh well.

 

[jmorris]

Aside from EMI there is a lot of other stuff involved too.

Recently I have been playing with load cells for a project and getting stable readings that are accurate with high resolution isn’t just a “click” away.

Even though it sounds simple to say things, at times, there is a lot more work to get them done. I have a new respect for my digital scales that work well though.

I also can understand why the engineers that made the RCBS chargemaster 1500 put in the auto zero function that keeps zeroing the scale when a tenth or two are all that’s added to the pan (even if it’s not the “right” way to do it, it gives the illusion of working right).

 

[rpenmanparker]

Aside from EMI there is a lot of other stuff involved too.

Recently I have been playing with load cells for a project and getting stable readings that are accurate with high resolution isn’t just a “click” away.

Even though it sounds simple to say things, at times, there is a lot more work to get them done. I have a new respect for my digital scales that work well though.

I also can understand why the engineers that made the RCBS chargemaster 1500 put in the auto zero function that keeps zeroing the scale when a tenth or two are all that’s added to the pan (even if it’s not the “right” way to do it, it gives the illusion of working right).

But what about all the sources of error in mechanical scales/balances? Friction, air currents, dirt and dust, imprecise and difficult-to-read markings, etc.

 

[jmorris]

But what about all the sources of error in mechanical scales/balances? Friction, air currents, dirt and dust, imprecise and difficult-to-read markings, etc.

What about them?

I have found it very easy to get a fairly cheap mechanical scale to detect a change of a single kernel of powder. Just a switch that can detect movement better than my old eyes.



Go back and watch the 2nd video in #44 and you can see the much more expensive CM 1500 can’t come close to the resolution of the much cheaper 505 at the end of that video.

A number of factors can cause errors in both types. I admit to playing with mechanical ones more and just now learning load cells, amplifiers, input voltage stabilization, offset drift/creep, aging, thermal expansion, residual stresses, hysteresis...and then you get to figure out how to get the components to work together and deal with the elements that all scales have to.

It’s pretty easy to program an output to any number of positions past the decimal but if all you do is average and zero out any change, that doesn’t make it able to resolve any more accurate than an old beam scale.

 

[rpenmanparker]

What about them?

I have found it very easy to get a fairly cheap mechanical scale to detect a change of a single kernel of powder. Just a switch that can detect movement better than my old eyes.



Go back and watch the 2nd video in #44 and you can see the much more expensive CM 1500 can’t come close to the resolution of the much cheaper 505 at the end of that video.

A number of factors can cause errors in both types. I admit to playing with mechanical ones more and just now learning load cells, amplifiers, input voltage stabilization, offset drift/creep, aging, thermal expansion, residual stresses, hysteresis...and then you get to figure out how to get the components to work together and deal with the elements that all scales have to.

It’s pretty easy to program an output to any number of positions past the decimal but if all you do is average and zero out any change, that doesn’t make it able to resolve any more accurate than an old beam scale.

Your conclusion is totally false. The electronic scale has the resolution, but it is programmed to rezero itself. It is seeing the 12 particles as drift. Thst isn’t a fault of electronic balances but rather programming. You do have to choose your equipment wisely. Very simply nothing works better with less operator error than an electronic balance ...as long as it is programmed properly.

 

[jmorris]

Your conclusion is totally false. The electronic scale has the resolution, but it is programmed to rezero itself.

If it wasn’t programmed to zero itself and instead show a .xx resolution, it would just be values floating around constantly. Have you ever been inside one of them and seen the load cell they use?

Very simply nothing works better with less operator error than an electronic balance ...as long as it is programmed properly.

That conclusion has a lot of variables in it as well, not to mention there is a lot more to it than a program. The difference between a $10 harbor freight digital scale and a $2000+ .001g one is more than just a program.

This is the load cell used in the CM 1500 for example.



That .01 gram = .154 grain, RCBS optimistically truncates this to .1gn in the manual.

Optimistic within the load cell capabilities given by the manufacturer much less the plastic components that have to interact with said load cell.

 

[Toprudder]

That .01 gram = .154 grain, RCBS optimistically truncates this to .1gn in the manual.

Optimistic within the load cell capabilities given by the manufacturer much less the plastic components that have to interact with said load cell.

I don't believe the "300g/.01" listed on the load cell is a claim of resolution. The output from the load cell is completely analog, from a bridge circuit, unless I am missing something.

 

[rfwobbly]

The RCBS comes with a grains to grams conversion chart, which I understood meant that it read in grams. Why else would you need to convert?

In Europe load information is given in metric measures. Bullets and powder are weighed in Grams. So the label is to help sell the scale in Europe.

With that said, and what I've read here, the Redding isn't much more than the RCBS, however, the Redding looks to be made from plastic.

If you look at price, then you're looking at the wrong thing.

The great thing about the RBCS 505 and Dillon Eliminator (which are basically the same scale from Ohaus) is that the minor adjust goes to "10". On the cheaper scales where the minor adjust only goes to "5" you need to be ever-mindful that an adjustment to (say for instance) "0.2" could mean your load is XX.2gr or XX.7gr. You have to force yourself to remember the extra 0.5gr to mentally add in.

That to me, that is a safety issue.

 

[Load Master]

There are many variations of a bridge strain gauge circuit. Some are quarter-bridge strain gauge circuit (cheaper) all the way to a full-bridge strain gauge circuit (higher cost). Some have temperature compensation some don't. Most strain gauge bridges are rated in millivolts of imbalance produced per volt of excitation, per unit measure of force. The voltage for most strain gauges is around 15mV/V per unit. If it is designed for grams, that would be 15mV per gram. This value goes through an analog to digital converter (ADC). This puts another level of complexity into the final reading. Cheaper scales may have a 4 bit ADC and more expensive have anywhere from 8 to 20 bit ADC.

My point, to generalize the comparison, balance beam scale versus digital scale doesn't make sense. The only possible way to do this is knowing more about the two scales being compared to each other. You can't just say that one is better than the other.

The old idiom, "You get what you pay for" probably plays more of a factor than stating a balance beam is better than a digital, or digital is better than a balance beam. Just my humble opinion.

 

[jmorris]

I don't believe the "300g/.01" listed on the load cell is a claim of resolution. The output from the load cell is completely analog, from a bridge circuit, unless I am missing something.

This is a concise overview on the subject.

http://kb.mccdaq.com/KnowledgebaseArticle50043.aspx

This is the load cell in question.

http://www.hzloadcell.com/pid114862...ingle-point-load-cell-for-jewellery-scale.htm

 

[rpenmanparker]

This whole thread is bizarre. I have been involved in weighing things as finely as 0.0001 gram for more than 50 years and never needed to know or care about how the scale/balance works. Just buy according to specifications that match your needs and be done. If it doesn’t do what it claims it will, get your money back. Amazon is a good source for that strategy.

 

[jmorris]

My point, to generalize the comparison, balance beam scale versus digital scale doesn't make sense. The only possible way to do this is knowing more about the two scales being compared to each other. You can't just say that one is better than the other.

Just buy according to specifications that match your needs and be done. If it doesn’t do what it claims it will, get your money back.

I think you two are both saying the same thing, in different ways.

“Digital balance” can mean this,



Or it could mean this.



One is under $15 and would be a step down from most common beam scales, the other is closer to $5,000 and would be a step up from most common beam scales. Lots of other stuff in between too so general statements like “a” is always better than “b” are just false.

 

[rpenmanparker]

Let me paraphrase what Mark Twain said about watches. The similarity between them and scales is remarkable.

“A man with one scale always knows what something weighs. A man with two scales can never be sure.”

 

[jmorris]

That too depends, they don’t make check weights for watches and his assumption was that the two instruments disagree with one another.

With an assortment of check weights an operator can be fairly confident in the results they are getting as long as they are in the right ranges in terms of value.

If I had a half dozen all give me the same value I would have even more confidence that the value was correct (despite understanding that all could be incorrect). If I had two scales that didn’t agree with one another, I would test them against the others I have and give the incorrect one to my niece for weighing her jewelry projects...

 

[Toprudder]

One is under $15 and would be a step down from most common beam scales, the other is closer to $5,000 and would be a step up from most common beam scales. Lots of other stuff in between too so general statements like “a” is always better than “b” are just false.

I worked in a lab environment years ago, and was part of an automation team that wrote programs to perform drug assays. There was a Sartorius electronic scale in the system I was working on, that somehow managed to fall off the table one day. (No one saw me do it, but I did fess up). The curved glass door to the scale broke, and JUST THE DOOR cost $1700.

I would not mind having one of those to use for reloading, but would never want to pay for it, nor do I need more capability than what the equipment I have now gives me.

 

[rpenmanparker]

That too depends, they don’t make check weights for watches and his assumption was that the two instruments disagree with one another.

With an assortment of check weights an operator can be fairly confident in the results they are getting as long as they are in the right ranges in terms of value.

If I had a half dozen all give me the same value I would have even more confidence that the value was correct (despite understanding that all could be incorrect). If I had two scales that didn’t agree with one another, I would test them against the others I have and give the incorrect one to my niece for weighing her jewelry projects...

It is a joke about the human condition.