Recently I have noticed bart and francis has merino wool / inox conductive yarn. (https://www.bart-francis.be/index.php?item=–150-meter_cone&action=article&group_id=128&aid=4531&lang=EN) This sounds really interesting! I have ordered it immediately, and just have got the package. Here is the first try out of the measurement and comparison to the plug and wear conductive yarn.

The spec of the yarn is “82% TeXaS extra fine merino 17,8Micron + 18% iNoX rostfree steel alloy 316 filament (3 x 2/48 Nm)”. By looking closer, the yarn is made out of 3 strand of 2/48 Nm yarn plied together. Through the magnifier, it looks like each strand is a wool (2/48 Nm) wrapped with thin long strand of iNox (steel fiber).

One of my interest is the thickness of the yarn as I would like to use it with hand crochet, hand knitting, knitting mills and hand knitting machines. The conductive yarn that was sold by Plug and Wear (later sold by sparkfun and not it is out of production) is 10Nm/3.
The unit Nm is “No. of 1000 metres (Kilometre) in One Kilogram (from http://www.sriyadithatextile.com/quality/count-conversion)”, so the larger this number is, the finer the yarn is. the number after / is the number of ply.  The yarn from bart and francis is 48Nm yarn x3, so it makes 16Nm if my calculation is not wrong… When feeling/looking at these two yarns and comparing it, the bart and francis yarn is definitely thinner, a bit thicker than half the thickness… which matches the calculation.

Now I am testing the electrical property with multimeter. And here is a big difference. The Bart and Francis yarn is made of long thin iNox fiber, so there are not a big difference between relaxed state and stretched state. While the plug and wear yarn is made of short steinless steel fiber mix and it has a significant difference between relaxed and stretched state.

Bart and Francis Merino wool Inox yarn

Plug and wear conductive yarn

I have not tried to knit/crochet with the Bart and Francis yarn to further make the comparison as textile sensors. But I think we will need the yarn made of shorter steel fiber. The nice thing about the Bart and Francis yarn is that it is made of merino wool fiber, and this will allow us to dye them easily at home or with natural dyes. Also, the original yarn is almost white and it will show the color well. I will try to contact Bart and Francis to see if they will be interested in making them with shorter steel fibers (they have mentioned that they can take a group orders to make new yarn as we want)