The other great thing about Nighthawk's and other digital read out alarms is they provide you with a number for the peak level detected. This helps troubleshoot the difference between the low battery chirp and alarm activation...I know they have different sounds, patterns and sometimes volume but this is often overlooked by kids, elders or allegedly spouses when you're not home The digital read out also allows you or the FD to determine if the situation is getting better or worse with a quantifiable number...