How accurate is advertised rope weight?

Giw Nou wrote: Dude, did you just came from the 70's?
The "consumer grade scale" as you name them, do not deviate 1%. Not even 1 per thousand actually. In any rate, a scale deviating 271g per 3,2kg is broken; not deviating.
3,484g is the exact weight of the rope as I already said. Not a single gram more or less. What is even worse for you, is that a random 20€ kitchen scale read that 3,484g.
That's to show that you are rather unfamiliar with modern scales accuracy actually.
But, you know, scales are just electronic equipment. And as we all know electronics often break down (I hear you say). You're right. Let me check this safety carabiner (which kong claims is 70g) for a moment.... oops it's 70g actually. Noooo, but what's going on with petzl adjama harness purchased back in 2008 supposed to be 435g? Eeehm, it's exactly 435g! Mind you, that's on the same scale the rope was measured! (that's me being sarcastic).
ok, ok, one last try, the edelrid mega jul (announced at 65g). Suddenly the kitchen scale reads 72g. Maybe it's just broken after all! (That's me being sarcastic again)

Funny thing is that I've already said that all other equipment has not even a single gram deviation in my previous post. But you keep insisting that the scale could be off.

You are either really bad at reading other people's posts or.... an edelrid employee? (There's a 3rd option actually but I don't want to get banned).

"Arbitrarily" treating the rope as a cylinder, accounts for a volume of 0.0146m^3 and a total 0.0146m^3 * 20g/m^3 = 0.292g of added weight to the rope due to humidity.
0.3g in 3.2Kg!
Do you really think considering the rope as a cylinder was the problem?

Say I was off a rather improbable 100%(usually error is accounted for 2-7%) in my "arbitrary" assumption. Then the total difference is 0.6g! Again that's for the whole 3.2Kg of the rope! Would you like to say that my calculations are 1000% off? Just for fun? Then the added weight is 30g. Still, the distance from Edelrid's claim to reality is 271g. I think your depth of understanding is missing another 240grams. So, you see where this goes? It goes slowly but steadily to show that it's you the one who is completely out of his depth.

The elongation problem.
Forget about me treating the elongation as linear. Again, just for fun, let's use the 80Kg (not the 10Kg added weight during the UIAA standard):
63m with 7.4% elongation is 67.662m.
And at 51g/m it SHOULD have been 3,450.76g
But no. It's still 3,484g
Again, you see where this is going? I smell dollars. Lots of them.

Last but not least, I included some photos with the measurements I just wrote about.

Please pay extra attention into the last one. I weigh the harness again, but this time without the metal bowl of the scale. I just pressed the harness into a sphere with my hands (it obviously retracted a lot when I released pressure) and placed it on the scale.
Do you see that it reads correctly even in that way? Now, my friend, that's how much a "consumer grade scale" is going to deviate in 2020. What a terrific piece of technology humans are going to be able to produce just fifty years after the age you currently live, eh?
But not to worry, when you'll be living in 2020 you will too be able to buy such an incredible scale for only ~20€. Amazing, huh?

Bye-bye my friend and please do not quote me again because you made enough fool of yourself already. I, for once, am not going to answer to you again.

As I said the interest in the humidity is that the nylon absorbs water (and changes the ropes size and length. If you insist on your bonkers theory that it relates to the weight of the moisture IN the air IN the rope then you must also take into consideration  the weight of the air ABOVE the rope. This is 1.03kg/cm2 so your rope has 5 .580,54kg resting on top of it, as your scales are only reading 3,484kg your rope must have a negative weight of 5,577.056kg which should help with you next send.  

The static elongation isn't measured with a 10kg weight.

Edelrid don't perform the certification measurements themselves, they are done by an independent laboratory.​​​​

Jim Titt wrote: Nylon 6 6 absorbes up to 3% of IT'S OWN WEIGHT.

So, is it up to 3% of its own weight or less than 2% of its own weight? Hmmm which of you is more credible? Jim Titt from Germany, paid by Edelrid, with a second account as "Mike" or.... UIAA certification?

With this in mind let me quote myself once more:
A completely wet Canary rope (let me remind you that "completely" means having absorbed not more than 2% of its own weight) should weight (according to Edelrid's advertising) somewhat less than:
63m * 51g/m * 1.02 = 3,277.26g
But, the same rope, in real life, completely dry is:
3,484g
So, for the last time: water, moisture, humidity or whatever, CANNOT be held responsible for such a deviation in weight..

You see now why I purposefully ignored your first post? The same goes for your second one too. I'll keep ignoring you as long as you pretend you didn't see the deviation in Mega Jul, which is ~10.8% heavier than advertised. And, in this case, made of solid steel!!! So you can't try to confuse people with your mumbo-jumbo nonsense like you tried to do about the rope. It's steel dude! Cold, solid, steel from hell! Right in your face!

But wait a minute! Isn't that number really close to the Canary which is ~8.4% heavier than advertised?
Heeey! Wait a minute here!!! Could that be a standard policy of Edelrid? Advertising smaller weights for their products? In a sport that weight really matters?
But then again why are you and me having this conversation? You already know about it! You work for them!!! Come on now man, get out of my face please!

My guess is that the weight "advertised" for climbing gear is the average weight from a sample.  How much do individual items vary from the average?  Don't know but I assume that weight variation likely follows a "normal distribution", thus + or - 3 sigma from the mean.  Or maybe it's a truncated distribution, no -, just +.
The small absolute differences in actual weight from claimed weight probably don't contribute to sub-par climbing performance for most of us.  

Giw Nou wrote:

So, is it up to 3% of its own weight or less than 2% of its own weight? Hmmm which of you is more credible? Jim Titt from Germany, paid by Edelrid, with a second account as "Mike" or.... UIAA certification?

With this in mind let me quote myself once more:
A completely wet Canary rope (let me remind you that "completely" means having absorbed not more than 2% of its own weight) should weight (according to Edelrid's advertising) somewhat less than:
63m * 51g/m * 1.02 = 3,277.26g
But, the same rope, in real life, completely dry is:
3,484g
So, for the last time: water, moisture, humidity or whatever, CANNOT be held responsible for such a deviation in weight..

You see now why I purposefully ignored your first post? The same goes for your second one too. I'll keep ignoring you as long as you pretend you didn't see the deviation in Mega Jul, which is ~10.8% heavier than advertised. And, in this case, made of solid steel!!! So you can't try to confuse people with your mumbo-jumbo nonsense like you tried to do about the rope. It's steel dude! Cold, solid, steel from hell! Right in your face!

But wait a minute! Isn't that number really close to the Canary which is ~8.4% heavier than advertised?
Heeey! Wait a minute here!!! Could that be a standard policy of Edelrid? Advertising smaller weights for their products? In a sport that weight really matters?
But then again why are you and me having this conversation? You already know about it! You work for them!!! Come on now man, get out of my face please!

Actually I own a climbing equipment company in competition with Edelrid but if you want to see ghosts carry on.

I wrote a lengthy response but accidentally deleted it and I don't really care to retype it. So basically:

Did you honestly just accuse Jim of making a second account in 2012 in case someone decided to argue metrology with him?

You don't understand compounding error or statistical variations.

Both Jim's comment and the UIAA spec can be correctly applied when you consider the UIAA spec is for a dry treatment and Jim's is plain 6,6.

WRT my comment on the solid cylinder-I hope you never try to understand how pack towels work when Nylon and polyester only absorb x% of their weight.

ETA: I weighed my megajul on my kitchen scale-64g and have now concluded that I didn't get the entire device I paid for.

Giw, I'm not saying this accounts for the entire discrepancy, but "A 10kg weight wouldn't elongate the rope even a meter" is a big misconception.  I got numbers in the 5-7% range when I played with it (hard to define precisely because even with 0 weight the rope's length has a few % of hysteresis).

Serge Smirnov wrote: Giw, I'm not saying this accounts for the entire discrepancy, but "A 10kg weight wouldn't elongate the rope even a meter" is a big misconception.  I got numbers in the 5-7% range when I played with it (hard to define precisely because even with 0 weight the rope's length has a few % of hysteresis).

As I posted earlier I measured 5,3% for a 10mm rope so a thinner one is going to be more. Using the static elongation figure is a waste of time as it is derived from a rope already stretched then measures the difference in length between a 5kg load and an 80kg load. And as noted above, the 3% moisture content is the maximum industrial standard for the nylon stock before manufacturing, the process may call for it to be higher or lower and what moisture content a particular batch of ropes might have is anyone's guess.

I don't even know what to say about the accuracy of your modern scale & your lack of understanding of professional standards. When I was manufacturing product every measuring device, micrometers, calipers, scales, levels were sent out every 60 days to be calibrated. If anything was dropped it was put out of service & sent out for calibration. Even our shipping scale had to be calibrated.