Myth busting - What causes digital scale zero drift and can it be fixed?

[Jim Watson]

The compressors kicking on were sending RF powerful enough to interrupt the sensor

My PACT will go nuts if the Dillon case feeder is running. Vibration or voltage, I don't know.

 

[Blue68f100]

One thing to try is when your not weighing (between drops), keep the pan on the tray. I found this helps a bunch in eliminating drift due to hysteresis. This keeps the zero at zero, and not a negative number. I do this when I'm checking my weights off of the LoadMaster 1500 with my GP250. Once the LM dispense I then pour the charge into other pan setting on the tray. I Let the LM dispense the next charge while I'm checking the last one. I discovered your more likely to get drift when the scales is not at zero. Keeping the pan on eliminates this problem. Now if your getting drift at zero then you have a issue you need to fix. Which is the whole purpose of this thread.

There are some digital scales that auto zero, so be aware.

 

[LiveLife]

My PACT will go nuts if the Dillon case feeder is running. Vibration or voltage, I don't know.

Probably both.

There are some digital scales that auto zero, so be aware.

Hmmmmm ...

 

[bluejay75]

Trickling into the pan will make your scale walk. I have found that throwing a touch over and picking powder out holds zero longer and not drift.

 

[LiveLife]

we have very high precision ... noticed some hard to explain drift in the readings that didn't correspond with the internal monitoring units ... moved all of our wall-outlet powered sensor units to isolated circuits, got them into really good insulators designed for -50C and used battery units for all of the sensor IC's - and the drift went away. The compressors kicking on were sending RF powerful enough to interrupt the sensor IC's for a few milliseconds and recalibration took a few clock cycles.

Very good point.

I think if we take a moment and step back to take a deep breath, we will realize that our hobby of reloading has moved away from the typical 0.1 gr resolution of beam scales to greater and greater resolution, sensitivity/detection and repeatability of digital scales.

The "zero drift" we are seeing with digital scales is not just nuisance to our task of reloading rather we need to approach it as a "positive side affect" of precision equipment and measurements that could be representative of variables that are influencing the strain gauge/load cell.

Let me ask. How many of us maintain laboratory level consistency of our reloading areas in terms of temperature, air movement, humidity, level surface, electro-magnetic field, etc.? Not many.

So the "zero drift" we are seeing may not all be reflection of "inconsistent" digital scale rather on a greater part environmental variables that are exerting on the digital scale stacked on top of internal variables.

As many other members already posted, if we are pursuing greater level of consistency, we must first minimize/eliminate variables that pose greater impact on finished rounds' consistency before we consider variables that pose lesser impact. In the same light, before we consider minimizing/eliminating internal digital scale variables like the load cell mount plate, we must first minimize/eliminate external environmental variables.

 

[Blue68f100]

Let me ask. How many of us maintain laboratory level consistency of our reloading areas in terms of temperature, air movement, humidity, level surface, electro-magnetic field, etc.? Not many.

Guilty as charged. My excuse is that I worked R&D for 20+ yrs. It's a natural extension.

 

[LiveLife]

And we are not talking about whether more precise metering/weighing of powder will produce smaller groups.

Not at all.

This thread is about objective approach to addressing "zero drift" many members reported whether they are cheaper ~$20 consumer grade scales or more expensive lab/analytical grade scales. It is an extension of recommending use of check weights/pin gauges to verify the accuracy/repeatability of any scale/calipers.

Once we minimize/eliminate the "zero drift", we can then better use the scale for reloading purposes.

But with that said, there's more.

There are some digital scales that auto zero, so be aware.

I did not know that.

So if that's the case for you, more the reason to use check weights (especially in the powder charge range you are using) to verify the scale.

As I already mentioned, unless you are shooting for small groups at 600-1000 yards, 0.1 gr powder charge variance may not be a big enough factor as there may be other reloading/shooting variables that could overshadow for you to minimize/eliminate first.

 

[Mark_Mark]

When an EMP strike occurs or a new ransomware through the power grid, all electronic scales will be useless.

I been talking about EMP strike vs. reloading way back! Lee Scoopes, Lee Loaders, manual calipers, a Book made from paper (lol)

I can load in the candle light!

 

[LiveLife]

I been talking about EMP strike vs. reloading way back! Lee Scoopes, Lee Loaders, manual calipers, a Book made from paper (lol)

I can load in the candle light!

I have Ohaus 10-10/RCBS 5-0-5 as back up.

My current set up of Lee ABLP/Dillon 550C with dial calipers and printed load data in a binder only require sunlight for me to reload.

I prefer to not have an open flame on the bench.

And I don't think we need to do a "myth busting" thread on beam scale drifting ...

 

[GeoDudeFlorida]

Let me ask. How many of us maintain laboratory level consistency of our reloading areas in terms of temperature, air movement, humidity, level surface, electro-magnetic field, etc.?

Remember Bluto in Animal House? I make him look like a neat freak.

 

[Mark_Mark]

When an EMP strike occurs or a new ransomware through the power grid, all electronic scales will be useless.

YEP!

 

[Engineer1911]

.......................

.............. if we are pursuing greater level of consistency, we must first minimize/eliminate variables that pose greater impact on finished rounds' consistency before we consider variables that pose lesser impact. In the same light, before we consider minimizing/eliminating internal digital scale variables like the load cell mount plate, we must first minimize/eliminate external environmental variables.

What are your group sizes at what range? Are you seeking smaller groups with your shooting? Or is this just higher level writings about your continued pursuit of perfection in reloading while diligently avoiding any mention of shooting results?

 

[JFrank]

Since we already have thread drift....I know people that have very expensive lab scales accurate to .02 and remain lost on how to develop a repeatable load, find a node or really know what a good load looks like . All the internet blather won't help them shoot small.
Charts and graphs are nice but the target doesn't lie, get whatever scale gives consistency then learn how to use it.

 

[LiveLife]

What are your group sizes at what range? Are you seeking smaller groups with your shooting? Or is this just higher level writings about your continued pursuit of perfection in reloading while diligently avoiding any mention of shooting results?

And we are not talking about whether more precise metering/weighing of powder will produce smaller groups.

Not at all.

This thread is about objective approach to addressing "zero drift" many members reported whether they are cheaper ~$20 consumer grade scales or more expensive lab/analytical grade scales. It is an extension of recommending use of check weights/pin gauges to verify the accuracy/repeatability of any scale/calipers.

Once we minimize/eliminate the "zero drift", we can then better use the scale for reloading purposes.

 

[PWC]

Not to be snarky, but the best "fix" for a digital scale, is a properly set up beam / balance with a set of calibration weights. Not as fast but always more consistent, gravity in your local area never varies.

Real question is how do you "feed" the scale?

 

[LiveLife]

From OP ...

Myth busting - What causes digital scale zero drift and can it be fixed? ... this thread is about zero drift of digital scales so no comments about beam scales

 

[JFrank]

Ok so let me ask this question, our electric scale has zero drift but check weights confirm the scale resolves correctly once zeroed to the same. What is the problem with the scale if any ?

 

[bluejay75]

Ok so let me ask this question, our electric scale has zero drift but check weights confirm the scale resolves correctly once zeroed to the same. What is the problem with the scale if any ?

Are there scales with zero drift?
I think the scale gets tricked sometimes and gets stuck on the light or heavy side requiring you to tare it out and or rezero it. I think all scales do it. Some more than others. Some more often than others. And all with different reasons. Of the ones I use 2 don’t really like me trickling into the pan while on the scale. One is sensitive to the air conditioning or ceiling fan. None seem too sensitive to being level.

 

[LiveLife]

our electric scale has zero drift but check weights confirm the scale resolves correctly once zeroed to the same. What is the problem with the scale if any ?

No problem as long as zero does not drift.

Sure, you can "tare" and verify with check weights to be accurate but do you need to repeatedly "tare" after calibration?

Point of this thread is to consider different internal and external factors that will drift zero so as to eliminate/minimize as many of these variables as possible ... all the way to adjusting load cell mounting plate screws so factor of ambient temperature rising won't affect plastic base housing to influence the load cell to change readings (Yes, that's how sensitive these scales are).

And another question persists that prompted this thread in the first place. "Are we blaming the zero drift to the scale not being aware that it may be external variables that are causing the zero drift?" Like using scales in hot/cold temperatures outside of specified range and not using fresh batteries, etc.

Are there scales with zero drift?

Some more often than others. And all with different reasons.

And that's my goal of this thread, for us to consider these different reasons whether internal or external so we can minimize zero drift. BTW, here's the OP:

Myth busting - What causes digital scale zero drift and can it be fixed?

 

[JFrank]

So imo zero drift can be a non factor as long as the scale calibrates to for example 20grains and resolves 20 grains accurately and does not drift during resolution.

 

[bluejay75]

So imo zero drift can be a non factor as long as the scale calibrates to for example 20grains and resolves 20 grains accurately and does not drift during resolution.

Once it has drifted it thinks your pan is heavier or lighter. So you’re going to be 20 grains plus the drifted amount.

Or that’s my opinion. So I rezero and retare whenever the drift won’t correct with the pan off.

I’m one stage up from rookie so I’m reading intently.

 

[LiveLife]

So imo zero drift can be a non factor as long as the scale calibrates to for example 20grains and resolves 20 grains accurately and does not drift during resolution.

As I previously posted, I believe 0.1 gr resolution verified by check weights is "good enough" for most reloading applications (That is if your scale verifies check weights in the powder charge range you are using - Let's leave out the issue of verifying sensitivity/detection down to 0.1 gr with 0.1 gr check weight).

Now, let's say you have a scale that only displays single place to the right of the decimal point and it drifts by 0.1 gr. Depending on how software is programmed to "round up", we may have 0.1 - 0.15+ gr variance from start of powder charge to last charge or until the zero drift is noticed.

Key is, will this 0.1 - 0.15+ gr variance in powder charge show on target? I believe that will depend on other reloading AND shooting variables. So as I previously posted, until we are able to eliminate/minimize these other reloading/shooting variables, we may not see the powder charge variance from zero drift on target. (See below ETA)

But let's say you are a match shooter or OCD reloader who managed to eliminate/minimize these other variables to the point where 0.1 - 0.15+ gr will show on target. That's where this thread would be pertinent, to reduce powder charge variance so reduction in group size could show on target.

And if you are not a match shooter but puzzled about why your digital scale drifts, this thread outlines variables that could be eliminated/minimized so a determination could be made whether the digital scale is defective/faulty or external variables are causing the zero drift.

ETA, if you are using a powder measure, you now have an added reloading variable of powder throw variance. Below are 10 drop weight variance from C-H 502 micrometer powder measure that gets added to the digital scale "zero drift" - https://www.thehighroad.org/index.php?threads/powder-measures.873198/#post-11601797

Now, if you are a long distance/precision shooter that trickle powder charge and needs to resolve powder charge to a single kernel, this is not an added variable but if you use a powder measure, you need to factor this variable as stacked to zero drift, it may show on target. (Will 0.2 - 0.3 gr powder charge variance show on target when many pistol start/max charges are around 0.5 gr?)

• Alliant Unique - .24 gr
• Alliant Red Dot - .22 gr
  
• IMR Target - .22 gr
  
• Alliant BE-86 - .14 gr
  
• Alliant Promo - .12 gr (Yes, the reblended powder with mostly large round flakes now meter much better)
  
• Nobel Sport Vectan Ba 9.5 - .12 gr (Similar granule structure as N320 but cut shorter)
  
• Winchester W231/Hodgdon HP-38 - .12 gr
• Lovex D032-03/Shooters World Clean Shot - .10 gr (Comparable powder to AA #2, fine ball powder)
  
• Alliant Sport Pistol - .08 gr (With more consistent granule size smaller than W231 like N320 diameter but cut thinner, best metering powder along with Bullseye)
  
• Alliant Bullseye - .08 gr

So as I posted previously, if there are other reloading/shooting variables that could overshadow the effects of zero drift of scale, we may not see on target until enough variables are eliminated/minimized.

 

[JFrank]

Once it has drifted it thinks your pan is heavier or lighter. So you’re going to be 20 grains plus the drifted amount.

Or that’s my opinion. So I rezero and retare whenever the drift won’t correct with the pan off.

I’m one stage up from rookie so I’m reading intently.

We calibrate scales to a check weight then push the tare function, now reweighing the check weight should varify resolution, place your pan on the scale, write that weight on the underside of pan in Sharpie.
We are at the mercy of a digital display and possible drift, it isn't the drifting g of 00.00 that is problematic it is the drifting of the resolved charge that can mess up are ES ,so if my comprehensive ability isnt failing me this thread is touching on these questions.

 

[LiveLife]

I think for some, the "Edited To Add" content of post #72 may shed some light on the subject why zero drift of digital scale could show on target.

 

[bluejay75]

So I know the exact weight of my pan to .00. I can tell if powder is stuck to it somewhere or if it has dust barely visible to the eye on it. So the pan is a constant check weight for me. I can see when the scale drifts or if something is stuck to the pan. Most of the time something is of the pan and wiping with a used dryer sheet usually gets me back to the right weight.