Kidde Nighthawk Plug-In Carbon Monoxide Alarm

This review is for a Kidde Carbon Monoxide Detector, Plug In Wall with 9-Volt Battery Backup. The door covering the battery is difficult to remove. There are no instructions about installing the battery. Looking at the back it appears the cover can just be slid off, but it requires a screwdriver flat tool to pop it off. I never ‘trust’ a “life saving” device without first testing it. The push button test is nothing but an alarm test. I tested the Kidde alongside a battery powered less expensive Awatin CO alarm. I ran gasoline vehicles in an enclosed area to build up CO. I brought the Kidde and a battery powered Awatin in for testing. The Awatin alarm went off for quite a long time but not a peep out of the Kidde. So I pushed the button on the Kidde to see what level of CO it sensed. The Kidde indicated a 329 (and silent) while the Awatin said 213 (beeping all the time.) After the Kidde went over 600 it sounded an alarm. Then I took both out in fresh air to clear the alarms and brought them back into the test area. Once again the Awatin sounded first. The Kidde sounded sooner than last time, somewhere between 250-350. I suppose a –slower- response time means less false alarms. I personally prefer a faster response time ** From the Kidde website Carbon Monoxide Level Alarm Response Time 40 PPM 10 hours 50 PPM 8 hours 70 PPM 1 to 4 hours 150 PPM 10 to 50 minutes 400 PPM 4 to 15 minutes Carbon Monoxide Levels and Their Symptoms 200 PPM Slight headache, fatigue, dizziness, and nausea after two to three hours. 400 PPM Frontal headaches with one to two hours. Life threatening after three hours. 800 PPM Dizziness, nausea, and convulsions within 45 minutes. Unconsciousness within two hours. Death within two to three hours.