How heavy are 1 kg weights really

[halocline]

I've seen variation of at least 20% in the old weights hanging around the dive shop where I did my DM. I would hope that new weights would be a little closer.

 

[hg frogman]

I thought that is a Thailand thing.....

Not only. In Egypt (and in many other countries) it's the same story. Extremely common, actually. So when I work there I keep the same weights all the time, and when possible I go to the shop next door to have them weighed on a balance to make sure.

Metric vs imperial units are part of the issue. Often the units are not written on the weights. Many weights are 2 pounds (0.880 kg) or 3, 4, 5, 6 pounds ... and the DM or counter guy doesn't care about the difference. Unless it's for pedagogic purpose (often much needed ...) as already stated in this thread.

Bad moulds (artisanal) are another part. Sometimes with producers thinking that 2 pounds = 1 kg. I have seen weights given for 2 kg that were a mere 1.6 kg.

When in doubt, weight-check becomes a matter of trial and adjust. No big deal provided one knows what's going on with the weights.

 

[GrumpyOldGuy]

I travel with a small digital scale to check my baggage. I started to use it to check my rented weights. Since many are not marked, it is a simple way to make sure I have the right weight every time. With 3 divers and 3 different weight requirements is makes like a it easier.

 

[spectrum]

After felling like an idiot a few times, being under or over weighted with the exact same weight I used before I started to check.
I borrowed 2 normal 1kg lead weights from 2 dive centers and put it on my digital scale and one had 820 gram and one 1100
So 5 kg are either 4 kg or 5.5 considering that there aren't any more extreme. I have the feeling that there smaller 1 kg weights around as well.

Are that imperial weights? Or just bad molded?

Commercial production (like Sea Pearls) are for all intents and purposes are spot-on. My limited experience with resort weights varies. Many are proud of their weights cast locally from dive finds but in terms of accuracy they are crap. In many cases there is no legible marking of the intended weight.

Getting the luggage scale to do double duty is a nice idea.

Pete

 

[ijdod]

I see this all the time, not just at resorts, but in the Netherlands as well. A lot of weights sold here are actually imperial weights, but those are generally referred to as their rounded metric equivalent; so 2 lbs = 1 kg. Metric weights are available, but from personal experience I would assume weights to be imperial.

 

[h90]

thanks everyone that explains a lot.....

 

[Leadking]

Reminds me of the story of a customer who had not ordered weights from me in a while called to place a new order. At the end of the conversation I asked her why she was back. She explained she had been getting a better price from a local supplier. I said "what happened?" and she went on to explain that they could not understand why their students were wearing so much weight and decided to put a five pound weight on the scale and found it weighted three and a half pounds.

I told her that if price mattered I could sell her three and a half pound "five pound" weights at a good price too!

 

[h90]

Reminds me of the story of a customer who had not ordered weights from me in a while called to place a new order. At the end of the conversation I asked her why she was back. She explained she had been getting a better price from a local supplier. I said "what happened?" and she went on to explain that they could not understand why their students were wearing so much weight and decided to put a five pound weight on the scale and found it weighted three and a half pounds.

I told her that if price mattered I could sell her three and a half pound "five pound" weights at a good price too!

I just came back from Malaysia. Was diving there. The DM asked me how much weight I need: -->6kg
He told me: no 4 kg should be more than enough for me.
His 1 kg weights were much larger and felt like the double of the last 1 kg in Thailand.
And of course it was more than enough....
And he kindly explained me that too much weight is bad....hard to swim aaaarrrrgggghhhh like I would came fresh from the OW training...

 

[Walter]

A 1 kg blocks weighs 9.8 newtons (kilos are a measurement of mass, not weight) on earth, about 1/3 of that on Mars and about 1/6 of that on the moon. Of course a lead weight marked 1 kg probably doesn't contain 1 kg of mass.

To get to your actual question, it is common to see lead weights that do not weight the amount advertised. The good news is (unless you are using a great deal of lead) the amount they are off is so slight as to be meaningless. It is quite easy to compensate for the difference from one weight to another using your lungs.

 

[h90]

A 1 kg blocks weighs 9.8 newtons (kilos are a measurement of mass, not weight) on earth, about 1/3 of that on Mars and about 1/6 of that on the moon. Of course a lead weight marked 1 kg probably doesn't contain 1 kg of mass.

To get to your actual question, it is common to see lead weights that do not weight the amount advertised. The good news is (unless you are using a great deal of lead) the amount they are off is so slight as to be meaningless. It is quite easy to compensate for the difference from one weight to another using your lungs.

I'll keep that in mind in case I dive on the Mars.....
As I try to have only the necessary weight with me, having 30 % less is pretty uncomfortable.