# Perimeter breach resistance threshold

**URL:** <https://community.zymbit.com/t/perimeter-breach-resistance-threshold/362>\
**Category:** ZYMKEY4\
**Created:** [October 7, 2018, 1:33pm UTC](https://community.zymbit.com/t/perimeter-breach-resistance-threshold/362 "2018-10-07T13:33:00Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Alon](https://avatars.discourse-cdn.com/v4/letter/a/f05b48/32.png) [@Alon](https://community.zymbit.com/u/Alon)\
**Post date:** [October 7, 2018, 1:33pm UTC](https://community.zymbit.com/t/perimeter-breach-resistance-threshold/362/1 "2018-10-07T13:33:00Z")

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Hello.

You have mentioned in the spec that a 2 feet 30 AWG wire or thicker should be used for the peremeter loop.  
I’m assuming that the circuit monitors the resistance of each loop, and it assumes that a breach has occured if the resistance rises above certain level.

Since we’re designing a costum flex PCB for the peremeter, it would really help us undertsand what is the resistance threshold. (The Min and the Max values)

Please advice.

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<div class="post-metadata">

**Author:** ![Phil\_S\_Zymbit\_1](https://avatars.discourse-cdn.com/v4/letter/p/45deac/32.png) [@Phil\_S\_Zymbit\_1](https://community.zymbit.com/u/Phil_S_Zymbit_1)\
**Post date:** [October 7, 2018, 6:41pm UTC](https://community.zymbit.com/t/perimeter-breach-resistance-threshold/362/2 "2018-10-07T18:41:18Z")

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Nominal Operating Design Requirements for your Flex PCB are:

Closed circuit resistance \< 10Ohms  
Open circuit resistance \> 100MegOhms to ground or to return trace.

These should be pretty easy to achieve with standard flex PCB processes. If you need further information let us know.