Winding Bobbel yarn cakes: which length counter?

Hello everyone,
we're currently winding our first Bobbel yarn cakes for crochet projects. 
Thanks to Stefanie, it's very easy to determine the required lengths. 
The yarn winder is also okay so far. 
now it's about determining the length of the yarn.
The yarn is tensioned over a tensioner and then fed into the length counter, from there to the yarn winder. 
When we use our length counter from fishing supplies 
Link removed, mod.
we keep getting different values. Sometimes we measured 222 meters, but when measuring again it was only 198. 
Deviations are up to 15% 

now our question: is the meter counter not well suited for paraffined yarn Nm28/2, or are we doing something wrong? 

are there any recommended counters? 
we've already looked at the “standard” length counter and considered others too, but they also don't look suitable for the thin yarn. 

thank you in advance 

Philipp

Hi Philipp,
welcome to our forum.
Please don’t include links to external sites in your posts.
Our community can surely give you a few more tips on winding bobbles.
Good luck. 

Hi Philipp,

maybe this will help:
Virtually every type of yarn—except for fishing line or, for example, tightly twisted sewing thread—has a certain degree of elasticity or stretch. This varies in degree depending on the material and the twisting.
Plant-based fibers are the least elastic. That’s because, in nature, they don’t need to provide warmth. Some elasticity is introduced during spinning or twisting so that the material feels at least a little “cozy.”
Animal-based yarns have the most elasticity. They all come from mammals, and their hair or fur needs to keep them warm. The more crimped the raw material is, the more elasticity it has. You can stretch a yarn like this, but it snaps back as soon as the tension is released. That probably explains why you’re getting different readings.

To get accurate measurements, I would never stretch a yarn unless it’s pure polyamide filament. But I would never knit or crochet with a material like that either.