Increased electrical resistance as a result of wear and tear

I let me get a new belt straight again. Use this for years. Am very satisfied with it. The only drawback: after some time, the belt does not work properly. Then there is increasingly absurd pulse values ​​or dropouts. This accumulates then more and more. Was also in the past like this. This applies both to the previous model with the metal mesh textile cover, as well as the new version with the conductive rubber pad. The latter is to be incorporated by the way better and more comfortable.

I have not exactly followed the life. The indicated generally one to two years but I would confirm about. I liked the question left no rest, what is actually the cause, and if you can extend the life after the occurrence of the problems mentioned by simple measures again.

My theory: the electrical resistance of the conductive coating increases by wear (welding, abrasion, washing). In addition I have made appropriate comparative measurements between the old and new belt. The mentioned in a previous post corrosion of pushbuttons never occurred to me the way. The electrical contact via the pushbuttons is still perfectly even at the old belt. Even otherwise, he seems actually not particularly worn. I have washed him always good after each use, and there are no visible deposits available.
For resistance measurement I used a common simple multimeter. A direct placement of the probe tips to the rubber surface I promised little reproducible measurement results. Therefore, I have compressed the two outer, distant from the ends of the snaps rubber surface, and then each set the two test prods to one of the push buttons. The resistance values ​​were fairly stable and easily reproducible. Also rub and squeeze more or less has caused no significant changes. (If you continue to move the position of compressing inward, the resistance decreases naturally.)

The new belt levels was approximately 550 ohms. With the old contrast at about 500 ohms (not a typo!) Since I am surprised more that there still something left.

The next question was whether it is more likely here to have an effect on the surface and below the rubber coating is perhaps even more conductive. Could be that the weld has been solved, the conductive particles only at the surface.
Since I had not much to lose the old belt, I've tried the following:
- Surface with nail file editing (no significant change)
- Surface with lighter fluid rub (no significant change)
- Finally forcibly penetrate with the probe tips in the rubber; has changed nothing and even more amazing, exactly half of the resistance value of the previous measurement method give (half because it allows only one side and so half the tape length has been measured)

Conclusion: The wear alters the material over its entire cross-section. So it's not surprising that washing or other measures also not change anything because off more than worsen. (Except were explicitly cases where on the surface of a pad has settled. Since cleaning could certainly help.)

Why still 5 points? Because this is probably due to normal wear of the materials used and the financial cost of spare me seems appropriate. (Maybe there would be a better material. High-tech from space research. This would then but probably a much higher price.)

Additional effect of this examination: I can do both, remeasure battery and strap. Before, I was never sure whether it is not yet on the battery and have then frequently changed nothing.