Review on Carbon Alarms Battery Operated 7 by Jon Manning

The alarm was tested by burning cardboard directly under the alarm. Nothing has happened. The only one of the 6 that actually set off the alarm, I actually had to put burning cardboard on the alarm for more than 3 minutes. I even tried enclosing them in a small 20 inch box made out of glowing paper. Five minutes later I opened the box and the smoke poured out in huge quantities and the signaling sat still, no sound. Checked the battery installation, checked the test button, everything else was fine, just no smoke detected.