"NetBotz appliances with the use of third party 4-20mA sensors can be used for detecting leakage of FM-200/Halon.
The following third party sensor will work with the NetBotz 4-20mA pod:
The SSG-MCD Suppression System Guard
This system detects Halon1301 and FM-200 fire suppression agents and optionally it can be built with 4-20mA output.
SSG-MCD User's Guide (see page 8)