Eurosec is the make of your alarm panel not the sounder Bill,yours could be one of the many makes out there but novaguard springs to mind.
The eary novaguard sounder's chirped in minus temperatures but that was years ago now so for yours to start at this stage is probably moisture on the pcb or a failing SAB ( battery).
I suggest you get an engineer out for a quick inspection and a SAB test if you want the use of your system,
In the meantime you could shut the system down if you so wish by :
Removing mains power to the panel (pop the fuse out of the spur if fitted),
Open the panel and ignore the tamper alert or outside sounder,
Disconnect the battery,
Let the sounder sound off until the SAB ( battery ) dies.
It will sound at a reduced level but remember mains off first.
e manno
December 2012