How to tell which is accurate weight

[TheNiteSiren]

I am having a small issue with my bathroom scale. I have been dieting the last three weeks. Once a week in the morning I weigh myself. The problem is that the scale will say one weight then if I get off and try again, the number will suddenly be 5 pounds lighter.

 

[Cumference]

I'm afraid that there is little to do if the weight is broken, but to get a new one.

They get old and worn, and it is not a good sign, if you can't get consistent measurements.


Make and type of the scale?



But you can check the following:

- Are the batteries fresh (if electronic)?

- is it standing on something level, with good contact for all "legs"?

- compare to another weight. When visiting friends, go to the toilet before you leave, and sneak onto their bathroom scale.
They may not be right either, but it is a reference.

Or you can go shopping, and try out the weights in different hardware stores.

 

[amofiga]

If it is an electric type scale that has batteries, try changing the batteries. Ours gets a little funky when the batteries are running low. If it's the old fashioned scale with springs, make sure it's on a hard level floor and that all of the little supports under it are on the floor.

Also remember that the relatively inexpensive Wal Mart and Target or Bed Bath and Beyond scales that you get for $15-20 bucks are probably only about 5% accyrate in the first place. They probably will vary 2-4 pounds out of a hundred on any given time you stand on them. They aren't designed for weighing out rocket fuel.

The only really accurate scales are the old fashioned "balance" type things in doctor's offices IF they are well calibrated. I used to love to watch the differences in men and women as they would sometimes stop into the nurse's office at work to check their weight. Guys walk in, get on, slide the little thing around till they get a reasonable balance and go about their day. Women.... take off shoes. Even take off jewlery and scarves. They would strip if they had to..... work that little balance thing till it would be as low as possible and exhale. I'm sure they stopped in the ladies room first to pee. Men are from Mars and we don't give a shit.... women are from Venus and cry if we put on a half pound. It's all in the attitude that makes you sexy ladies. Really.

 

[SquirtnBrat]

I use the electronic scale at the gym. No matter what I weight I throw my arms up in victory! I made it there, made it threw my workout, that alone is victorious!

 

[NippleMuncher]

Calibrate your scale with a fresh, unopened, 5 pound bag of flour or sugar. Set the weight on the scale, then tap the scale plate to "settle" the weight. Adjust the adjuster as necessary to the weight of the bag. Take the bag off and repeat the process again several times, sans adjusting the scale. Now it is ready for you to weigh yourself. Assuming that it is a dial scale and not electronic, you can step on it a little harder as you get on so that it spins up past your weight, then it will settle itself as it bounces back down upon your actual weight, if you know what I mean. The other thing you can do is weigh yourself several times and average the results.

As was said, most scales tend to be on the cheap side (poorly made ), making their accuracy not all that great, however, it's good enough as a general guideline.

 

[Zeb_Carter]

Move it off the carpet onto a hardwood or tile floor.

 

[beautyandbrains]

Usually the old school dial ones are more accurate. But better than a scale is judging with measuring tape, that doesn't lie. Water weight can fluctuate, but you may be losing inches too

 

[Zeb_Carter]

Usually the old school dial ones are more accurate. But better than a scale is judging with measuring tape, that doesn't lie. Water weight can fluctuate, but you may be losing inches too

So from the time he steps off the scale until he steps back on, which occurs only minutes apart, he loses or gains water weight?

 

[Weird Harold]

I am having a small issue with my bathroom scale. I have been dieting the last three weeks. Once a week in the morning I weigh myself. The problem is that the scale will say one weight then if I get off and try again, the number will suddenly be 5 pounds lighter.

Another point to consider about Electronic scales. You should recalibrate before the first weight; step on the center of the scale and release to recalibrate.

If you don't do that, the scale will recalibrate when you step off the first time and will weigh the second time with a different calibration. Calibration becomes more erratic as the batteries discharge; weak batteries will cause erratic readings.

With an analog scale, step hard and release a couple of times to make sure it returns to Zero consistently. If it doesn't, replace it.

 

[beautyandbrains]

So from the time he steps off the scale until he steps back on, which occurs only minutes apart, he loses or gains water weight?

I didn't say the inaccuracy within minutes was due to water weight; it is obviously an inaccurate scale. Having the scale on carpet instead of a steady and even floor, not calibrated well, any of those are a factor. Instead I recommended using an old school dial scale, or just not using the scale altogether and opting for measuring tape to weigh inches rather than pounds because one's water weight can affect the scale as well (as a generality, not stepping on and off minutes from each time). Hope that clears things up.

 

[Zeb_Carter]

I didn't say the inaccuracy within minutes was due to water weight; it is obviously an inaccurate scale. Having the scale on carpet instead of a steady and even floor, not calibrated well, any of those are a factor. Instead I recommended using an old school dial scale, or just not using the scale altogether and opting for measuring tape to weigh inches rather than pounds because one's water weight can affect the scale as well (as a generality, not stepping on and off minutes from each time). Hope that clears things up.

That's what the OP was talking about. And water weight, for men at least, doesn't fluctuate that much on a daily basis...until you get old and are up every hour on the hour trying to empty your bladder.

I said in an earlier post, get the scale off the carpet and on a hard surface.

*shrugs*

 

[subwannabe]

I don't think there is such a thing as a good scale. I went on a search once looking at all kinds of scales in all kinds of price ranges. Read the reviews on them all and in the end I couldn't find one that you could really consider completely reliable, not even the expensive ones. The scale I use weighs a few pounds heavier every time you step on it so I usually just go by the first reading. I have also noticed that it makes a difference where you stand on the scale so I try to stand in the exact same place every time I weigh. I like the idea of the flour or sugar bag. I had never heard of that before but is a great idea. Of course that just means it is weighing 5 pounds accurately. Who know what happens once you get over 100.

 

[GiggLeGasm]

nothing will tell you more about the success of your workouts more than a clean pair of jeans fresh out of the dryer.. keep working!

 

[shiny5437]

What if the degree of error was proportional to the weight applied? You could weigh a known weight several times and calculate the variance of the observed values. Do this a couple of times with other known weights then plot the variances against the weights. Weigh yourself several times, calculate the variance of your results then compare to the graph calculated above.

I have no idea if this works but it seems like a neat idea.

 

[Zeb_Carter]

What if the degree of error was proportional to the weight applied? You could weigh a known weight several times and calculate the variance of the observed values. Do this a couple of times with other known weights then plot the variances against the weights. Weigh yourself several times, calculate the variance of your results then compare to the graph calculated above.

I have no idea if this works but it seems like a neat idea.

Math major, right?

 

[shiny5437]

Frustrated scientist

 

[Cumference]

Frustrated scientist

Indeed!

It is a classic problem!

http://withfriendship.com/images/c/11229/Accuracy-and-precision-picture.png

 

[shiny5437]

Indeed!

It is a classic problem!

http://withfriendship.com/images/c/11229/Accuracy-and-precision-picture.png

Ooh, tell me more!

Yes, if you were throwing darts at a dartboard you could tell how far away it is by the degree of dispersal of where the darts hit. The closer you are the tighter the grouping, the further you are the more spread out.

 

[Cumference]

Ooh, tell me more!

Yes, if you were throwing darts at a dartboard you could tell how far away it is by the degree of dispersal of where the darts hit. The closer you are the tighter the grouping, the further you are the more spread out.

Yes, but the problem here is, that we do not know Siren's true mass.
Relative to the illustration, we do not know, where the center of the target is.

From what she has told, it is clearly imprecise, but is it also inaccurate?
We are in one of the lower two cases, but we can't say, whether it is one or the other.

 

[Zeb_Carter]

Ooh, tell me more!

Yes, if you were throwing darts at a dartboard you could tell how far away it is by the degree of dispersal of where the darts hit. The closer you are the tighter the grouping, the further you are the more spread out.

See, you think darts, whereas I think sniper rifle.

 

[shiny5437]

Yes, but the problem here is, that we do not know Siren's true mass.
Relative to the illustration, we do not know, where the center of the target is.

From what she has told, it is clearly imprecise, but is it also inaccurate?
We are in one of the lower two cases, but we can't say, whether it is one or the other.

Ah, but we don't need to know what number the person throwing the darts is aiming at, just the degree of dispersal. However you do need to calibrate the dispersal (or variance in the case of the weighing scales) against know values. Whether the error is inaccurate or imprecise I'm assuming that the error is proportional to the magnitude of the true reading.

 

[Cumference]

Maybe.

But a load cell will also be less accurate at low loads (too little load to give a reliable signal) and when overloaded (maybe even loaded to plastic deformation.... When that happens to your bathroom scales, consider a diet!)

 

[shiny5437]

Maybe.

But a load cell will also be less accurate at low loads (too little load to give a reliable signal) and when overloaded (maybe even loaded to plastic deformation.... When that happens to your bathroom scales, consider a diet!)

Hmm, I guess that scuppers my argument. I was thinking in more mechanical terms whereby the load was causing some sort deformation of the internal workings. It still might work but you'd have to do a heck of a lot of weighings with a whole range of known weights to construct the weight-variance graph in the first place.

We just need TheNiteSiren to volunteer to do the experiment for us! I reckon she'd only have to lift a total of 55tonnes [metric].

 

[Cumference]

We just need TheNiteSiren to volunteer to do the experiment for us! I reckon she'd only have to lift a total of 55tonnes [metric].

It will be good exercise!

(But less than two trips to the gym, now I come to think of it)

 

[Hypoxia]

The next question is, what is done with the revealed numbers? I have great interest here. I've dropped a great deal of weight in the last year and still have a bit to go to reach my goal. (Off already: 35% of greatest body mass. Left to go: 12% of current mass.) I weigh myself DRY and naked on a consistent fully-charged digital scale (DRY means sans piss+shit). I'll see a 1-3lb difference over a few hours, even after ingesting very little. But the numbers chart my transformation pretty well.

Then what? Why, it's the old BMI (body mass index) which was NOT designed for individual diagnosis, only as a population-comparison tool. BMI numbers are abused because they don't accurately account for height differences. I am quite tall; I'm not just a scaled-up midget. BMI basically is weight / (height^2) but some researchers say that weight / (height^2.1) or even a greater power(^2.3-2.7) is more applicable. If I use the squared (^2) factor, my current BMI is 31, edge of obese, and my target is 27, overweight. If I use the (^2.1) factor, my current BMI is 20, dead-on healthy, and my target is 18, edge of scrawny. So, should I keep going, or stay at my current weight? I'm getting a bit tired of a carrots+jerky diet.