13 hours ago, MrHappy said:

 

so the advantage is a high resistance fault when closed wouldn't generate a intruder signal unless it got to "tamper values"

 

I assume "high resistance" is x% of the circuits resistance values so 1k & 1k is quite narrow but at 4k7 & 4k7 its more forgiving ?

Chances are it will go to open value before it reaches tamper value

it does give early warning of contact failure

9 minutes ago, james.wilson said:

it does give early warning of contact failure

Works well if signalled on a dedicated high/low res channel as long as the customer calls an engineer before setting the system

Is it above 1200 ohms that you'd see high res? I seem to recall that?

19 hours ago, goncall said:

Works well if signalled on a dedicated high/low res channel as long as the customer calls an engineer before setting the system

qfa