Digital vs manual scales

overin2015

I have always been back and forth between 200-204 on my manual scale. Bought a digital scale and I weigh 214. Makes me wonder if I was always 214 or if the difference in the scales is a known fact. It is always 6 pounds difference between the two. Does anyone else know why that is? I am fine because the clothes are more what I go by but it would be nice to clear up this mystery. Both scales are on level solid ground, same time of day, same clothes, etc. Again I am not defined by a number but wanted to know if this is a known issue with the two types of scales. Doing the flour sack thing they both weigh correct.

Amanda4change

A slight error on the calibration of the manual scale can cause weight differences that increase as the weight increases. So while it could be correct at 10pounds (or seem to be exact) it can be 1/4-1/2 a pound off (could be even higher) times that by 20 (to reach 200) and you looking at an error ratio of +|- 5 pounds.

janiceclark08

They say manual scales can have the spring wear inside and weigh wrong. When I had mine it weighed 5lbs low from the start, I had it set up 5lbs to weigh, based on WW scales and Drs. My digital is getting old and it jumps around up to a .8 oz. difference. Maybe take new one back, in case it is defective and get another one, even different brand.

Christine_72

It's an unexplainable mystery that new scales always have you weigh more than the old ones.....

PAV8888

A->B -2.2lbs B->C +1.2lbs. Different scales, different numbers : - )

Digital scales are prone to lying. Most have one (some higher end models up to four) strain gauges. The gauges convert the force your apply into electrical signals. The stream of electrical signals is "averaged', interpreted by the scale, and a number is then shown to you.

Your or the scale's positioning, your imperceptible movements, the flex of the materials all conspire to potentially send a signal stream that would be "averaged" and interpreted as a different number if you were to step back on the scale a few minutes later.

Scale manufacturers (correctly) believe that consumers would interpret a bunch of different number to mean that their scales are not nearly as accurate and consistent as they make them out to be.

So they fudge!

Unless a new measurement is "AT LEAST" x-lbs or y-% different than the/a previously displayed one you are just shown the same number you were previously shown.

You are happy because your scale is consistent! But at the same time your scale is not trully showing you what it is measuring to the best of its ability.

In my case scale A had a "persistence" of about 0.5lbs. Scale B of about 1.6lbs!!!! and scale C apparently gives "real" and sometimes inconsistent measurements the first three times you get on it, but then "calibrates" itself into showing you a "calibrated" constant number if you continue getting on and off.

At least C waits till you start badgering it before it lies! These first three "semi-calibrated" measurements is why I broke down and bought it, in spite of the annoying wi-fi and body fat crap it subjects people to!

Interesting Experiment: bring a 1 or 2l bottle, filled with a cup of water (about 250ml), to where your scale is. Weigh yourself without the bottle. Weigh yourself while holding the bottle. Is the scale saying your weight has changed? Since 250ml is about 0.5lbs and most scales claim a 0.1lb accuracy... shouldn't it have? Now keep adding water and re-measuring till the scale shows a new weight. Now weigh yourself again, but without the bottle. Is your weight the same as it was before? Shouldn't it be the same if your scale is as accurate and consistent as it claims to be?

LAWoman72

My digital scale did weigh me heavier than my manual scale had, by about two pounds. However, with my manual, I was always adjusting to get it to 0, and even then I'd step on, step off and the needle would hover just after or before the 0 all over again.

I also notice that now, I weigh two pounds heavier on my doctor's scale, fully dressed, than I do at home naked; with two pounds accounted for the clothes, that puts my digital pretty much spot-on, at least with my doctor's scales. So that works for me.

I wouldn't worry about a few pounds. If you're a few pounds heavier than you thought you were, then that's okay, right? If it were a 25-lb. difference then you'd probably need to worry, LOL.

You're looking for a trend, a general downward trend (if your goal is weight loss). You'll see that downward trend whether you're starting from 214 or a slightly different number so I'd just keep weighing on the digital and go from there.

overin2015

Thanks for the responses. I love the technical stuff PAV8888! You all are right I need to just see the downward progression and not care about the weight. It was just frustrating to think I weighed 206 and seeing 214. That's a big difference and should have been noticeable in my clothes etc. I think I will just keep the digital one and then use it to see my progress. If I get to what looks like goal and it is 155 instead of 145 then so be it!

ncboiler89

overin2015 wrote: »

I have always been back and forth between 200-204 on my manual scale. Bought a digital scale and I weigh 214. Makes me wonder if I was always 214 or if the difference in the scales is a known fact. It is always 6 pounds difference between the two. Does anyone else know why that is? I am fine because the clothes are more what I go by but it would be nice to clear up this mystery. Both scales are on level solid ground, same time of day, same clothes, etc. Again I am not defined by a number but wanted to know if this is a known issue with the two types of scales. Doing the flour sack thing they both weigh correct.

Either one could be wrong, the digital or the analog, or they both could be wrong. Set something of known weight on each and see which one is correct or how much each is out of calibration.