LCR meter with overheat detectors (firewire)
 

Does anyone know why we use LCR meters on overheat and fire detectors (firewires) to measure the resistance instead of regular multimeters??

Thanks

From memory, measuring impedance of firewire/detectors.

that must be a candidate for answer of the year!
LCR meter/impedance you are a real genius aren't you.

The question however was why?

AC powered system.

Multimeter measures the DC resistance.
LCR meter is used as the firewire/detector has an AC sensing voltage, hence need to measure the impedance.

the question remains.....why?

A bog-standard multimeter measures resistance by applying a voltage and measuring a current. An LCR bridge measures impedance with zero current. Measuring under null conditions is more accurate, but also passing a current through a firewire is not the best way of promoting its general health and longevity.

PDR