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Line conditioner for scale drift??

BrushyHillGuide said:
I'm having some issues with drift on my scales and I just can't afford to buy a $1k scale. Anyone use a "line conditioner" for their scales? If so, which brand/model?

What about ferrite chokes/beads (http://www.oldwillknottscales.com/fair-rite-rct-2-ferrite-bead.html) -anyone use these with any success?
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Ferrite chokes are mostly for suppression of noise spikes on the AC line. They are also used for noise suppression in chopper-type regulated DC power supplies. They are not going to do anything to stabilize either an AC or DC supply. As far as drift goes, with a common digital scale a well-designed regulated DC supply helps some but is not the entire answer. Believe me, I have built several very well regulated supplies using different designs and my scale still drifts. The only thing that happens is when the heat pump and exchanger or other load kicks in on the power line I do not get a DC voltage variation. My scale still drifts but it is probably more to do with temperature changes and maybe air currents. I leave it on 24/7 to minimize the temperature stuff, but the strain gauge type scale is just going to drift. Period. That's why they have Zero and Calibrate buttons . . . .
 
May help some, may not.

You can try to use a circuit in your building that's not also powering fluorescent lights. Those should be kept far distant from your scale too BTW unless they have electronic ballasts inside. Or switch over to direct-wire LED tube fixtures.

Also try scheduling your measuring sessions for when power demand is lowest in your area.

Before I bought a magnetically-damped A&D Fx120i (about $650) I was using a Denver Instruments MMX-123 plugged into a small APS back-up/supressor/conditioner. Even WITH Ferrite beads on the power brick's low-voltage cable I infrequently had drift issues unless I did my powder measuring before 7 AM or after 9 PM.
 
I have 2 scales that do not drift.
One is the Pact made RCBS Rangemaster 750 and the other is the second generation Dillon Determinator. They are both battery powdered.

I had a first generation Dillon Determinator and it drifted so badly that it was totally worthless. It practically had to be calibrated for each weighing.
I left it on one afternoon and after a few hours drifted .7 grains. I had that scale a few years and I called Dillon about it. The tech told me that it was about all the state of the art was good for way back then. He said send it back and they would try to replace it with a better one. So it stayed unused in the top of the closet.
I called again and got the same response a few years later. Finally I called again when the scale was about 8 years old. They said send it back so it went back.
A week later I got a new scale of a different model and it works great. But I still only use digitals for weighing bullets and brass. I never ever use them for weighing powder.
 
It's not possible to say the ferrites will or won't help your scale in your environment . . . but it is very unlikely. Anecdotally I can tell you that neither ferites nor a lab-grade DC power supply cured fluttering, loss of zero, etc on any of my four strain gauge scales.

IME the most frequent cause of drift/flutter in a strain-gauge based scale is RF noise. Cell phones, wireless phones, microwaves, WiFi, fluorescent lamps/ballasts, etc are some sources.

Air currents and static electricity will affect both strain gauge and mag force scales. I had a strain gauge and a mag force scale start fluttering when I used an incandescent lamp to light the work area from over my left shoulder. Heat from that lamp caused a rising air current around the scales which was disturbed every time my hand entered that space, causing the scales to flutter. Live and learn . . . and now I use LEDs.

You could try some shielding around the scale, or turning off or removing transmitting devices from the area.
 
I've been using one of these for years now. I started using these when I had my Computer Service Co. way back in the 90's. The best on the planet as far as I'm concerned. It's a line conditioner and surge protector. It also has a Lifetime Warranty and $50,000 Ultimate Lifetime Insurance for connected devices. I use it and a horseshoe Farris magnet to clean up anything that might get past it. My scales are always spot on.
https://www.amazon.com/dp/B0000513US/?tag=accuratescom-20
 
brxbrad said:
I've been using one of these for years now. I started using these when I had my Computer Service Co. way back in the 90's. The best on the planet as far as I'm concerned. It's a line conditioner and surge protector. It also has a Lifetime Warranty and $50,000 Ultimate Lifetime Insurance for connected devices. I use it and a horseshoe Farris magnet to clean up anything that might get past it. My scales are always spot on.
https://www.amazon.com/dp/B0000513US/?tag=accuratescom-20
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I have the 2 outlet model of this item. My CM has yet to drift since I hooked this up.
 
I work daily with precision analytical balances (I'm a research chemist) that offer the precision and resolution we're looking for here, but those instruments cost thousands to tens of thousands of dollars. To reach a price we're willing to pay, some corners must be cut (vendors won't line up to sell to us below cost). Unfortunately, the instruction manuals accompanying our scales generally aren't very good at spelling out the steps necessary to have then operate to our satisfaction.

For stable zeros it's necessary to warm up for at least a few hours (they're generally left on continuously to avoid drift) and keep the room temperature fairly constant (within a few degrees).

Inexpensive scales such as these are commonly bothered by power line noise and transients, but those van be eliminated by using a filtered power strip; I use and recommend a Tripp-Lite isobar.

Static electricity can easily shift readings by a few grains, so it pays to wipe down all plastic surfaces with an antiststic such as a drier sheet. Don't wear nylon or other static-prone fabrics when working with the scale. A humidifier set to maintain 35% RH will help a lot.

It is necessary to isolate the scale from drafts and vibrations. Laboratory scales with this sort of resolution generally have a housing around the pan with sliding doors for access and vibration isolators in the feet. An air current that's not even perceptible can easily shift readings at the level of precision we're looking for, but opening and closing a door is a nuisance when you're trying to up the pace. I use a carboard file box (intended for archival document storage) with one end cut out placed over the scale. The side goes down so the box can be removed for filling with powder, etc. without disturbing the scale. I leave off the top (now facing forward) so I can work my Pact scale/dispenser. With the bench closing the bottom and the box closing three sides and the top, air currents have a hard time getting to the scale.

Vibrations are another problem - you don't want to have heavy equipment operating nearby, or foot traffic on a residential floor. You can make a vibration isolator by putting a heavy plate (Steel, stone, concrete, etc.) on a slab of soft foam, but it may not be effective; really good vibration isolators are expensive.
 
richinva said:
I have this one and no issues.
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Yep, that's exactly the product ronemus suggested in his post before yours.

What I can't accept is his recommended 35% RH unless maybe you live in the SW.

I can get 35% in the dead of winter when it's been -10 or below for a week & I turn the humidifier off but then my wife complains her hair stands straight up, the dogs won't come near me for fear of getting a shock in their nose, and rolling over in bed almost electrocutes me... and all the furniture falls apart.

I think 50% a more reasonable number; after all, static dissipates when the air's more humid, tends to build on surfaces when the air's dry.
 
No way I can obtain OR maintain 35% in my basement gun room. Lucky to get 50%.
 
The objective, I believe, is to maintain a minimum of 35% relative humidity to reduce static electricity; higher levels of R.H. will not be an issue with regard to static electricity.
 
ED3 said:
The objective, I believe, is to maintain a minimum of 35% relative humidity to reduce static electricity; higher levels of R.H. will not be an issue with regard to static electricity.
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And it is easy to maintain 35% relative humidity.
 
ronemus said:
...For stable zeros it's necessary to warm up for at least a few hours (they're generally left on continuously to avoid drift) and keep the room temperature fairly constant (within a few degrees).....
Click to expand...
I used to work with marine gravity meters, which are effectively precise scales mounted on stable platforms. They could NEVER be turned off. At least the heaters had to run all the time. Transporting one from lab to ship was a big deal.
 
JRS said:
And it is easy to maintain 35% relative humidity.
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35% minimum is NO issue...............:)

I missed the minimum statement, just because I saw 35% and thought, man, would I love to have that..........not in Virginia............
 
richinva said:
I missed the minimum statement, just because I saw 35%....
Click to expand...

Don't feel bad, I did too! Rereading that post just now (was minimum really there?) I saw 'humidifier' which clicked everything into its proper meaning.

My basement infrequently sees 45% RH during winter, closer to 55% usually. March - October has a DEhumidifier set @ 50% running 24/7. I collect the 'distilled' water it produces for washing brass....
 
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