Do fluorescent lights affect digital scales?
- Thread starter Cassidy
- Start date
Dusty Stevens
Shiner
Yes
How /why? Is it the blue noise of the electric? Or magnetic field?
It's the ballast that is causing the issue. It has an induced magnetic field surrounding it. The field is reduced when it has a metal housing around it, but some are plastic, their 'magnetic reach' is greater.
It will also have an impact on your beam scale too, they're magnetic dampened.
It will also have an impact on your beam scale too, they're magnetic dampened.
You might want to ask some of the tens of thousands commercial and industrial laboratories around the world which have relied on fluorescent lighting for decades. Or it would probably be more practical if you have a local pharmacy that compounds medicines to just look and see what type of lighting they use. I can assure you they have scales that are way more sensitive than what 99.9% of the people on here use.
That said they do produce low level EMI but your scale should be properly shielded. I have LED with my new house bur my old shop was fully fluorescent for years as was the the small lamp directly above my bench on the bottom of the shelf and I never had a issue with any scale
That said they do produce low level EMI but your scale should be properly shielded. I have LED with my new house bur my old shop was fully fluorescent for years as was the the small lamp directly above my bench on the bottom of the shelf and I never had a issue with any scale
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It could be because they're far enough away or you don't have a magnetic ballast. They're an older technology, electronic ballasts are far more common, at least from what I've seen around.
1) Yes, possible. This covers it though obtusely, not really a narrative. The basic issues are:
- Ballasts are high voltage and (were) magnetic.
- If not properly shielded and wired, they can produce RFI (interference through the air, across a wide range of frequencies).
- If not properly wired, they can produce interference in the household wiring which may be limited to the circuit it is on, or propagate across several, or emit RFI from the wiring itself.
- Not all "improperly" is a manufacturing or installation mistake, but is a choice in construction for cost, convenience (to the user) weight, etc.
- Of Course, Not All Fixtures. We Know. Anecdote yours works fine is not helpful.
- Electronic devices absolutely can get messed with by unexpected electrical or RF interference.
- FCC Part 15 (read the label on the back of your electronics) says that things do not emit interference and if they receive any they must work without serious issues. Like most regulations worldwide this is NOT tested (UL tests, not a regulatory agency) and the regulatory compliance department at the manufacturer asks the engineers if it complies, then they pinky swear to the government or certifying agency it's fine.
- Professions that use high precision instruments get them calibrated all the time. Drifting calibrations get chased down, and they'll find and fix the issues. We don't have those resources and... without that how do you KNOW your scale is still calibrated? Even the weight check reset is not the same as a calibration house.
If for nothing else, the sake of a good argument..... should we put a Faraday cage around our lights/scales/cell phones??
Bill Norris
Back in the Day
I swapped over to LED in my shop and (mancave) reloading room. I don't see any scale swings at all unless I forget to turn off the small portable fan directly above my loading bench.
Fans are definitely an issue. I run 2 dehumidifiers in my basement 24/7 until the heat is turned on. Neither unit is close to my reloading bench, but they do cause fluctuations with my Chargemaster 1500.
My WAG is that a line conditioner would help with that.
The metal housing IS an RF cage. Badly built ones leak. If you've taken apart electrical housings (or computers) you'll either find them very very sealed (folded and welded) on all corners or they have little fingers that interlock. Many vent, so have holes punched through them.
The size of the fingers and holes matches (a multiple of) the frequency of the emitted RF: a faraday cage.
Heat kills electrical and electronic components, and less metal is less cost so the part where good ballasts are sealed in SOLID metal housings (no frequencies to usefully isolate) is a hint of how noisy, across-the-spectrum, even the modern electronic ones are.
+1 to my mind also.
Dehumidifiers run compressors (like A/C, fridge) with huge startup load spikes. If you like the rest of your electronics, get them off that circuit or get a line conditioner to filter out these spikes.
I used a couple of these for a long time (now all my electronics are on UPSs with it built in, gave them to my musician neighbor who brings them to gigs as you cannot trust random power!).
Note that's retail. Check your local computer/electronics store as they are often on sale; I paid like $25 for one, $32 for another of this exact model.
I need to do that.
You're probably right but I just shut everything down as the Chargemaster warms up. I'm assuming that I'm getting consistent charges by some of my SDs. My first 6BR is getting low single-digit SDs with Varget and 15.5 when everything is right.
My humidifiers displace a great deal of air, them and the fans have to be off when using the scales. As far as the fluorescent lights, mine are no issue and any properly wired (grounded) set up 18" away should cause no issues.
With that said, incorrectly wired lighting can be a serious problem in many ways.
Ned Ludd
Silver $$ Contributor
Fluorescent lighting can affect the readout of a precision balance, but it doesn't have to. There are other common causes of interference with precision balances including the power supply itself, humidity, static electricity, etc. It is not difficult to test whether turning the fluorescent light on affects the balance reading. If not, there is no need to do anything with the lighting, and that would also suggest any issues with the balance readings originated from a different cause. If one is having issues with a balance, find the cause, whatever it may be, and fix it.
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