Michigan Grip Invitational

[Mikael Siversson]

I think you misunderstood me slightly.

You are talking about weighing the whole lot in one go whereas I was talking about weighing each plate separately.

It becomes very impractible if you don't know the real weight of each plate you use.

A WR attempt in vbar would mean that you have very roughly ten weight plates on the bar. If the scale has an accuracy of 0.5lbs we would have to multiply this number with ten which is 5lbs.

Once the plates are calibrated you can use them again next competition without having to calibrate them inbewteen. After a couple of years one can always check a couple of them again to test the effect of wear on their weight.

Regardless of the scale one buys it has to be calibrated by someone authorized to do so. No scale stays the same. They all drift to some extent.

Bottom line is, regardless of which scale one uses one have to make sure it is certified within the time frame that is recommended for this particular scale. Food store scales in Europe for example have to be of approved brands and have to be tested every two years. The certifying company will then give you a weight range within which they guarantee that the weight that you weigh will be. For example lets say that the certifying company certify a scale to be within 1/2lbs from 0-100lbs, 3/4lbs from 101-150lbs and 1lbs from 151-300lbs. So you weigh all your plates which would all fall within the lower range (0-100lbs) and the indicated value on the scale would be within 1/2lbs. Lets then load a vbar for a WR attempt. The vbar itself is 3.5 lbs, the 8 45lbs plates we use weigh a total of lets say of 352lbs, a 25lbs weigh 24.2lbs and a 5lbs plate weighs 5.1lbs. This all adds up to 384.8lbs. Please note that in this case the resolution of the scale is 1/10lbs and the accuracy 1/2lbs. We used a total of ten plates and for each one of them the margin of error is 1/2lbs, so in total 5lbs. This means that the weight lifted is 379.8-389.8lbs. The WR is 381.1lbs (if memory serves me right) so in order to be sure that this is truly a WR attempt one would have to add a 2 1/2lbs plate which would give us a total of (assuming the added plate weighs an indicated 2 1/2lbs) 381.8-392.8lbs. This would then be an unquestionable WR attempt. It is easy to realise that a higher quality scale with a better accuracy would improve the lifters chanses of beating the WR. Using a scale with an accuracy of 1/10lbs would mean that the original range of 379.8-389.8lbs would shrink to 383.8-385.8lbs. We would then not need to add a 2 1/2lbs plate and the competitor would stand a better chance of beating the record.

Edited May 15, 2006 by Mikael Siversson

[Mikael Siversson]

Bottom line is that a scale weighing 175 kg in increments of .5 lb is really much more precise--than the much less accurate figures that you've quoted.

The resolution of a scale (increments interval) may not be the same as the accuracy. You can have a scale with increments of 1/2 lbs but with a tested and certified accuracy of 1.2 lbs for example.

[oldtimer]

Mikael, Perhaps I misunderstood what you were trying to say--it sure sounded to me like you were ascribing less precision and hence less accuracy to the weight lifted. If you don't mean that, then it's a different case.

It seems much simpler to weigh the total weight lifted at one time if one is going for a record. If one is not sure whether the weight to be lifted is going to be a record, then one should weigh it before the attempt. It sounds like you're a person who strives for accuracy so I imagine you would have weighed any suspect plates on a calibrated scale ahead of time to avoid any embarrassing situations.

By the way a little piece of information from a man I talked to at Tanita Scales about certification. He pointed out that some coaches here in the USA, and I'm sure that this could happen elsewhere, have actually taken a scale and tampered with it before a wrestling contest so that their athletes could make weight--in other words cheating (In the USA in our NCAA wrestling contests, the competitors have to be weighed in on certified scales so that they can officially make weight classes.) Quality scales, like Tanita, also have a platform stabilizing device built in--which minimize attempts of athletes to lean. I found it impressive that when I weighed in for a weightlifting contest a few years ago and then took my socks off that the scale picked up the difference. It was just my way of checking whether the scale could truly discriminate differences of just a few grams.

Another point of nit-picking--to have a truly accurate scale--one needs to correct for the local gravity coefficient--which includes factors as latitude and altitude. A given weight/mass of 180 kg in Quito, Ecuador could easily weigh several 10ths of a kg less in Stockholm, Sweden. For those who think I'm kidding, I'm not.

There's another case of a shot-putter who took his 16 lb SP with him on an airplane to fly to a meet. When he arrived, his previously certified shot wouldn't pass the local muster --it weighed too light for a number of reasons.

[oldtimer]

Bottom line is that a scale weighing 175 kg in increments of .5 lb is really much more precise--than the much less accurate figures that you've quoted.

The resolution of a scale (increments interval) may not be the same as the accuracy. You can have a scale with increments of 1/2 lbs but with a tested and certified accuracy of 1.2 lbs for example.

I'm not sure that sort of discrepancy would be legal in this country for any scale legal for trade. Someone's bathroom scale or one used for private purposes--okay, but not scales certified for trade. If the increments are in 1/2 lb on a certified scale then the precision and accuracy has to be as I stated above. We actually have inspectors that travel around to places where food is weighed and certify the scales as legal for trade. If not certified the user is liable for fines. i would assume that would be the case in most countries, if not all, in the world.

[Mikael Siversson]

Another point of nit-picking--to have a truly accurate scale--one needs to correct for the local gravity coefficient--which includes factors as latitude and altitude. A given weight/mass of 180 kg in Quito, Ecuador could easily weigh several 10ths of a kg less in Stockholm, Sweden. For those who think I'm kidding, I'm not.

There is no need to panic about gravity anomalies such as latitude (which affects the distance to the centre of the planet) and other gravity anomalies (such as mountains).

In fact I would have guessed that a 180k weight in Quito, Ecuador would weigh more in Stockholm as the latter locality would be closer to the centre of the planet.

As I have said in the past, let's eliminate the uncertainties that we can. The USA and Sweden, England, Germany and Switzerland are all on roughly the same latitude.

Let me know if someone of you organisers are weighing your calibrated plates on the top of a mountain or perhaps along the shores of the Dead Sea.

[oldtimer]

Mikael,

It's nice to interject a little humor--although sarcasm takes things to a different level. Let me know if I misunderstood. You are right about Stockholm probably producing a greater weight. I said probably because there are local conditions that could be quite different than one would expect.

I got the impression that you were all about accuracy, so I replied taking you at face value. You mention something about being "roughly" at the same latitude. Well if it's roughly the same latitude and that's good enough for you then so be it. You might know that there are other factors involving calibration besides just the two that I mentioned. It sounds like you might be less concerned with accuracy than I had previously surmised. If it's good enough for Tanita, the scale mfr., to suggest calibrating a scale because of the differences in gravity around the world in order to insure accuracy, then I would have thought you would do the same. Why shouldn't grip sports take the same trouble that NCAA wrestling, Olympic lifting, and power lifting does with their calibrating the scales to be as accurate as they can?

Oh well.

[Mikael Siversson]

Why shouldn't grip sports take the same trouble that NCAA wrestling, Olympic lifting, and power lifting does with their calibrating the scales to be as accurate as they can?

As far as I know, they use the same approved weights in Olympic lifting regardless of where the competition is held. In other words they don't have seperate calibrated sets of weights for each location on the planet where a high level olympic lifting competition takes place. The calibration you are referring to refers to the scale they use to weigh the competitors.

I never said that we should at this stage use as stringent rules as they do in olympic high level lifting. We don't and we can't as we allow organisers to use non-Oly competition plates. In fact there are no approved one inch competition plates. They are all with a two inch hole (Eleiko etc.).

Taking into account the local gravity would improve the accuracy yes and so would calibrating the weights. Just because we don't consider local gravity at this stage does not mean that we should not use certified scales. It is better to eliminate one variable than to eliminate none of the two we are discussing. I can look into it and see if I can easily obtain local gravity data.

It sounds to me that you bought a scale and now wants to use for calibrating competition plates in spite of the fact that it has not been certified. The company that sold it to you would of course say anything they can to make you happy as a customer.

[Mikael Siversson]

If it's good enough for Tanita, the scale mfr., to suggest calibrating a scale because of the differences in gravity around the world in order to insure accuracy, then I would have thought you would do the same.

A locally obtained certified electronic scale should measure the actual local weight of a plate at this location (unless it is corrected to instead show the mass). The maximum variation in the weight of a given mass on the surface of the planet varies by about .5 per cent. In our competitions which are held in mid-latitudes and typically not on mountain peaks, the variation in gravity is probably around .25 per cent or less which is acceptable in my oppinion.

Knowing the local weight is sufficient in my oppinion, especially as I have never heard of that they would use different sets of weights in olympic lifting depending on the location. The weight plates of approved oly brands would have a certified mass and would feel a fraction lighter at low latitudes and high altitudes (provided the altitude is derived from a plateau of sedimentary rocks; a mountain with its deep roots will increase gravity, especially if it is of mainly igneous composition like the Andes).

Edited May 17, 2006 by Mikael Siversson

[oldtimer]

Why shouldn't grip sports take the same trouble that NCAA wrestling, Olympic lifting, and power lifting does with their calibrating the scales to be as accurate as they can?

As far as I know, they use the same approved weights in Olympic lifting regardless of where the competition is held. In other words they don't have seperate calibrated sets of weights for each location on the planet where a high level olympic lifting competition takes place. The calibration you are referring to refers to the scale they use to weigh the competitors.

I never said that we should at this stage use as stringent rules as they do in olympic high level lifting. We don't and we can't as we allow organisers to use non-Oly competition plates. In fact there are no approved one inch competition plates. They are all with a two inch hole (Eleiko etc.).

Taking into account the local gravity would improve the accuracy yes and so would calibrating the weights. Just because we don't consider local gravity at this stage does not mean that we should not use certified scales. It is better to eliminate one variable than to eliminate none of the two we are discussing. I can look into it and see if I can easily obtain local gravity data.

It sounds to me that you bought a scale and now wants to use for calibrating competition plates in spite of the fact that it has not been certified. The company that sold it to you would of course say anything they can to make you happy as a customer.

Mikhael, it is my understanding that they actually do have separate sets of Olympic weights at each location. However, the bars and plates have to meet certain standards of the IWF. I can't imagine the IWF springing for the freight bill for shipping a minimum of 300 kg of weights (the weight of just one barbell set) all around the world. Actually, each high level site has about 10 or 12 sets of Olympic barbells --all but one set for the warm up room.

Where do you think I said we shouldn't use certified scales? This is your implication. I never said that. My original intent was to reply to your warning that started out--"Hold on folks," or words to that effect--in order to clarify what you meant. You responded and did clarify that you were talking about--that you meant using 10 or so weights which would be weighed individually and could give you theoretically a very large error. You were talking about a 175 kg weight (please note you didn't say weights but weight--i.e. singular. Naturally, I assumed that you knew how they used to weigh weights for Olympic lifting and power lifting contests. What they did was to put the entire amount lifted all in one big pile on a certified scale and hence a 175 kg weight (barbell or whatever) couldn't possibly have the errors you described when it was certified to the nearest 1/2 lb or 1/10 lb. BTW, this is no longer necessary since major venues all have purchased weights certified by the mfr.

Secondly, your assumptions about my scale purchase are a little off the mark. For about $50 more I could have had my present scales certified--the mfr. rep told me not to bother--before I bought the scales. I would have paid the $50 if I had thought it was necessary. He didn't--see my comments above about that. Actually, if a scale isn't abused there's no practical need (unless requred by some organization) to re-calibrate it or re-certify it more often than about once every five years. I don't plan to abuse my scales hence I didn't want to waste the money. Hopefully, everything is clear now--well I can hope can't I.

[Mikael Siversson]

Mikhael, it is my understanding that they actually do have separate sets of Olympic weights at each location.

What I ment was that the sets they use are all purchased from an approved manufacturer which has one standard. In other words, as far as I know, all certified oly weights are certified to a specified tolerance of the mass, not to a variety of local weights. This would then mean that in olympic lifting high level competitions, they don't care about local variations in gravity other than for, I assume, the scale used to weigh the lifters.

However, the bars and plates have to meet certain standards of the IWF. I can't imagine the IWF springing for the freight bill for shipping a minimum of 300 kg of weights (the weight of just one barbell set) all around the world. Actually, each high level site has about 10 or 12 sets of Olympic barbells --all but one set for the warm up room.

I know this. Sorry if I expressed myself poorly. I am doing my best arguing in a language I don't fully master.

Where do you think I said we shouldn't use certified scales? This is your implication. I never said that. My original intent was to reply to your warning that started out--"Hold on folks," or words to that effect--in order to clarify what you meant. You responded and did clarify that you were talking about--that you meant using 10 or so weights which would be weighed individually and could give you theoretically a very large error. You were talking about a 175 kg weight (please note you didn't say weights but weight--i.e. singular. Naturally, I assumed that you knew how they used to weigh weights for Olympic lifting and power lifting contests. What they did was to put the entire amount lifted all in one big pile on a certified scale and hence a 175 kg weight (barbell or whatever) couldn't possibly have the errors you described when it was certified to the nearest 1/2 lb or 1/10 lb. BTW, this is no longer necessary since major venues all have purchased weights certified by the mfr.

A world records attempt should be recognised as such as it is performed. It becomes very impractical to unload all the weight and fish out a scale everytime someone has a go at a WR in a competition. Why is this suddenly such a huge problem? Arthur solved it and so did Eric Milfeld.

Knowing the weight of all individual plates well before the competition (by posting it on the GB) also provides us with a tool to check possible cheating.

Edited May 20, 2006 by Mikael Siversson