Health o meter 402LB Mechanical Beam Scale, Height Rod, 400 lb. Capacity, 10-1/2" x 14" x 3-1/4" Platform

This scale gives me the accuracy and precision I was looking for that I didn't have in cheap electronic bathroom scales. I showedthat its mass measurements are accurate by calibrating it with water of a known volume, using the density of water at room temperature to calculate the exact mass the scale needed to give me, and got the right answer to within the measurement error of the scale and the volume measurement instrument. I measured its precision to be plus or minus a half an ounce or so, depending on how you choose to quantify this variable.For two standard deviations as the quantification of the scale's error, that would be plus or minus an ounce or so. So in other words, if this scale tells you you're 150 lb 0 oz, there's a 95% chance that you're weight is greater than 149 lb 15 oz and less than 150 lb 1 oz, and not some other far-flung number. So it's pretty much to-the-ounce precision with this scale. You eat a 6-oz cup of yogurt, and your weight goes up by 6 oz on the scale (to within measurement error, of course); the scale will even pick up your weight loss due to breathing out carbon dioxide and water vapor + sweating/transpiration if you sit for an hour or two without doing anything.The scale is not for the faint of heart, mathematically and scientifically, though, if this idea is appropriately defined. You *do* have to assemble it yourself, and the "ounces" I'm talking about don't appear by themselves on the scale. You have to be familiar with fractions in order to use the comparatively user-unfriendly markings on it (e.g., that one-fourth of a division past two divisions, given that there are four divisions between each pound, would be 9/16th of a pound, or 9 ounces). Also, it requires a fair amount of manual dexterity to control that little slider on the beam with the required delicacy to get the precision I'm talking about -- plus you do have to watch what it's doing when it's coming to equilibrium and not forget whether the beam seemed to prefer the top or the bottom the last time you checked marking division 3 or whatever.So if you're looking for extreme accuracy and precision, ditching your cheap bathroom scale for this one would be a good idea. But if you're just interested in your approximate weight, rather than, say, the contribution of the weight of your clothes to your daily weigh-ins, just stick with a cheap bathroom scale that you can get for $20 or $30 at Walmart. They'll do fine for those purposes.

8 years in and the scale is still excellent! Original review follows...The scale just arrived (2 days!). It took 5 minutes to put together. Weighed me to within a pound or so of the electronic scale I am replacing. The difference is, when I step on and off the electronic scale, consecutive measurements can vary by a couple of pounds. This scale, I can step on and off as many times as I like and it does not give me different readings. Resolution to 0.25 lbs. I've found the way to get the best consistency from a scale like this is to find your weight (beam is somewhere between top and bottom stops), hold the end of the beam against the top bar, adjust the sliding weight downward slightly, then gently (slowly, without moving your body) release the beam. If the beam *just* moves down from contacting the top stop and stays clear, you have found your absolute minimum weight (for this scale) - I have not checked the absolute accuracy of the scale, since (as I said) it measures close to what I expected and I am more interested in consistency than absolute accuracy. I stepped on and off the scale several times and my weight stayed the same. I picked up 4 AA batteries sitting on the dresser (3.375 ounces, or less than 1/4 pound) and the beam contacted the top stop. In other words, without my stepping on or off, the scale detected that I had added 1/4 lb to my weight.The difference in weight between the beam just barely contacting the top stop and just barely contacting the bottom stop was ~1/2 lb. So, even if you aren't as nutty about obtaining maximum consistency, as long as the beam is somewhere between the top and bottom stops, you can be confident your weight will be "correct" (for this scale) to within +/- 0.25 lb.The scale is not as heavy-duty as I would like, but what do you expect from a ~$170 scale?. Based upon the construction, I believe that if I don't knock it over, toss it across the room, jump on it, or otherwise abuse it, it will be accurate in perpetuity and I will never have to worry about it getting wet or wonder whether or not the batteries are dying. If anything untoward happens over the course of the next few weeks or months, I shall update this review.