A battery-operated smoke detector is one which is not connected to your homes power supply.
You can purchase a smoke detector at any hard wear store in your area, if you can not find one there try looking online or at this website:http://www.smokesign.com/smokealarms.html?gclid=CLf8pIidkaoCFQJrKgodkRGaww
smoke...The reason that sometimes we cannot see smoke is because of the very tiny "particulates" that make up the smoke. A good smoke detector mwill sense smoke long before it can be seen. It is particles in air that are very very small that a smoke detector detects.
If you mean to interfere with a smoke detector on an airplane, that would be a federal offense. If you cover up a smoke detector in your own house, that would be not be smart to do but is likely not illegal. For rental properties or office buildings, you would probably have to check local building and safety codes to find out if it is illegal, but covering one there would not be a smart thing to do. Many codes in public buildings require working detectors.
There are basically two types of smoke detector; one type measures the opacity of the air to literally "see" if there is smoke. The other type tests for ionization that occurs when there is a fire. That type smoke detector uses a small radioactive chip to determine if freshly ionized smoke is present. It's a far more accurate means of determining the presence of fire and associated hazardous smoke. Many smoke detectors use a combination of both detectors. A separate type of detector is the carbon monoxide detector, which senses the presence of harmful carbon monoxide in the air. Most will even indicate the percentage of carbon monoxide. Note that carbon monoxide is typically present when a furnace or other heating device malfunctions.
Fernando J. Dibble was one of the inventors of the first smoke detector
There are basically two types of smoke detector; one type measures the opacity of the air to literally "see" if there is smoke. The other type tests for ionization that occurs when there is a fire. That type smoke detector uses a small radioactive chip to determine if freshly ionized smoke is present. It's a far more accurate means of determining the presence of fire and associated hazardous smoke. Many smoke detectors use a combination of both detectors. A separate type of detector is the carbon monoxide detector, which senses the presence of harmful carbon monoxide in the air. Most will even indicate the percentage of carbon monoxide. Note that carbon monoxide is typically present when a furnace or other heating device malfunctions.
Interlinked smoke detectors are smoke detectors wirelessly connected to one another. This is a good system for larger homes, and can be found at http://www.safelincs.co.uk/Radio-Interlinked-Smoke-Alarms/.
Perhaps a two-stage process. Firstly, gain access to the electrical output in the smoke detector, that drives the noise transducer. Use this (amplified?) to drive the mechanism of your electrically-operated lock.
Have Atleast one smoke detector on every level og your home and test them regularly
There are many places where one can purchase a counterfeit money detector. A good place is the website "Amazon" or the website "eBay" to purchase a money detector.
This would normally be a smoke alarm/detector. At the basic lengths, you should have a heat detector in the kitchen, smoke alarm in the hallway of every floor. I.e. the entrance hallway on the ground floor and the landing on the first floor, second floor etc. If possible, also put one in the loft/atic and the basement (if you have one).