5 ms·
Passive damping – Bathroom scales
- Syzygies 2y agoMost consumer bathroom scales are programmed to report exactly the same reading twice in a row, when the reading is close. Passive damping may be smart, but stupid always wins.
- bobbylarrybobby 2y agoInteresting. Mine consistently shaves off ~2 pounds if I weigh myself twice in quick succession.
- lultimouomo 2y agoThis happens on mine if I don't let the scale calibrate before the first measure. The scale turns on if you step on it, so it's tempting to just put both feet on in quick succession while the scale it's still off. That will give you a wrong reading. If you step off, the scale calibrates, and the next reading will be right. You should get two equal readings if for the first one you push on the scale with one feet, take it off, wait a few seconds, then weigh yourself.
- _yb2s 2y agoOh wow I always wondered why this happened as it felt vaguely weird, I was skeptical that these things were accurate enough to be so repeatable, but never suspected this.
- gurjeet 2y agoThis is why, between two successive measurements, I place one foot on the scale to measure the weight of just one leg (comes to 18-20 lbs). And the following (third) measurement is sufficiently different from the first one. I use this "weird trick" when I'm not happy with the first reading, and want a second opinion ;-)
- 01HNNWZ0MV43FF 2y agoThat explains why I've sometimes weighed myself, peed, and then found that I gained weight
- gruez 2y agoI bought a cheap $20 off amazon and it was seemingly accurate to 0.1 lb. I tested by weighing myself plus a bowl with varying amounts of water and there's no "report the same weight if the measurements are close" behavior you describe.
- rainbowzootsuit 2y agoOften I see these mixed up: Damping is restraining oscillation. Dampening is making something wet.
- amluto 2y agoI’ve never taken apart a bathroom scale or tried to measure any of the above, but my intuition is that this article completely misses the point. Bathroom scales don’t deform a whole lot, and humans are squishy! When you take a running leap onto a playground swing, you are part of an oscillating pendulum. When you step onto a scale, sure, there will be a transient, but there will also be a whole lot of noise as you balance, wiggle, breathe, etc, and I bet the latter is dominates the former. A self-respecting bathroom scale (not the kind that is intentionally biased to read the same number twice in a row) acts like a moderately low-pass-filtered sensor. As you move a bit, the number changes. So the scale is averaging over time, not waiting for some very stiff internal spring to stop oscillating.
- NotYourLawyer 2y agoThat does seem likely. You gotta think the scale is stiff enough that it’ll settle down in well under a second.
- senectus1 2y agowhen I renovate my bathroom I'm making a perfectly flat surface just for the scales. Bathroom floors are not flat and when you put scales on them the torquing of the scales messes with its mesurements. I can move my "smart scales" around the room and get a different result each time.
- Yodel0914 2y agoIt would be less work to turn "bathroom scales" into "bedroom scales". Bathroom floors are not level for a good reason.
- quesera 2y ago> Bathroom floors are not level for a good reason Most residential bathrooms do not include a drain in the middle, at least in my part of the world. Most residential bathroom floors here are as level as the tradesman can get them.
- 1d22a 2y agoHuh, interesting. That's not the case in Australia, in all the houses I've seen. I always thought it was smart, though.
- quesera 2y agoIt's very common (maybe even code?) in commercial bathrooms in the US as well. Not sure if the residential code is lagging, or if it's just not a popular design here.
- rainbowzootsuit 2y agoNo floor drains are required in commercial ICC code, but they're a really good idea. https://codes.iccsafe.org/content/IPC2021P3/chapter-4-fixtures-faucets-and-fixture-fittings#IPC2021P3_Ch04_Sec403.1 https://codes.iccsafe.org/content/IPC2021P3/chapter-4-fixtur...
- alliao 2y agothanks... I can rest easy that this is possible cause to why my kitchen scale is so slow... do not get a SOEHNLE Page scale if you value your sanity. It is so slow it can serve up counting down ads....
- euroderf 2y agoI tried repeatability on a few electronic scales at the shop and none had it, so I stuck with my old mechanical scale. Reason: It Just Works.
- davidpfarrell 2y agoSo my morning routine is: * Pee * Weigh (naked) * Perform morning routine * Pee * Weigh (naked) My old scale had 0.2 lb granularity and certainly repeated the previous value if you stepped in it again within some certain time. My new scale (Etekcity) is 0.1 granularity and often comes in at 0.1 or 0.2 lbs less on the 2nd weight in.