Smoke Alarms

The cadmium chalcogenide semiconductors (qv) have found numerous appHcations ranging from rectifiers to photoconductive detectors in smoke alarms. Many Cd compounds, eg, sulfide, tungstate, selenide, teUuride, and oxide, are used as phosphors in luminescent screens and scintiUation counters. Glass colored with cadmium sulfoselenides is used as a color filter in spectroscopy and has recently attracted attention as a third-order, nonlinear optical switching material (see Nonlinear optical materials). DiaLkylcadmium compounds are polymerization catalysts for production of poly(vinyl chloride) (PVC), poly(vinyl acetate) (PVA), and poly(methyl methacrylate) (PMMA). Mixed with TiCl, they catalyze the polymerization of ethylene and propylene. 

Most smoke alarms (Figure 19.1, p. 517) use a radioactive species, typically americium-241. A tiny amount of this isotope is placed in a small ionization chamber decay of Am-241 ionizes air molecules within the chamber. Under the influence of a potential applied by a battery, these ions move across the chamber, producing an electric current. If smoke particles get into... 

Slow step, 308 Smalley, Richard E., 250 Smog, 310,565 Smoke alarms, 516,517f Soap, 595 Sodium... 

True. Smoke alarms will sound long before the levels of smoke become dangerously high. This provides people with valuable time to evacuate a burning... 

T Some people taKe risKs to maKe life more interesting. 4o. SmoKe alarms in houses are essential. 

Light-silver-colored element generated from a plutonium isotope (241Pu) by beta decay. Never detected in nature. Chemically similar to Europium. A few tons have been produced throughout the world through regeneration of fuel rods. Americium is a good source of alpha rays. Hence it is suitable to measure thicknesses, as a detector in smoke alarms, and for the activation analysis of the tiniest amounts of substances. 

Some alarm systems are manually operated others use sensors that automatically trigger the alarms. Smoke alarms installed in residences are examples of automatic alarms. A number of alarm systems on the market today will also sound automatically if a radiological hazard exceeds a specified threshold. Automatic radiation alarm systems provide a number of advantages over manually operated alarms ... 

In contrast to systems that are set up to transmit local only alarms when the sensors are triggered, systems can also be set up to transmit signals to a central location, such as to a control room or guard post at the utility, or to a police or fire station. Most fire/smoke alarms are set up to signal both at the location of the event and at a fire station or central monitoring station. Many insurance companies require that facilities install certified systems that include alarm communication to a central station. For example, systems certified by the Underwriters Laboratory (UL) require that the alarm be reported to a central monitoring station. 

All the isotopes and compounds of americium are deadly sources of radiation and cause radiation poisoning and death. Precautions must be taken when working with it. The small amount of americium-241 found in smoke detectors in household smoke alarms is harmless unless the isotope is removed and swallowed. 

Nuclear wastes are sometimes divided into two categories low-level wastes and high-level wastes. The difference in these two categories is the intensity of radiation produced. Low-level wastes tend to produce relatively small amounts of radioactivity and pose moderate health problems compared with high-level wastes. About 99 percent of all low-level waste originates in nuclear power plants. Such wastes consist of protective clothing, trash, contaminated water, and contaminated equipment, such as filters. X-ray equipment, and smoke alarms. Worldwide, low-level wastes make up about 90 percent by volume of all nuclear wastes, but they account for only about 1 percent of the total radioactivity emitted by those wastes. 

The fire department s home fire safety escape trailer will be at your station during the month of June. At that time, each family in the community will be able to purchase up to three smoke alarms at a cost of only 3 each. Each family is also entitled to one fire extinguisher at a cost of 8. Which of the following statements describes the city s new program most clearly and accurately ... 

Similarly, you may be presented with a diagram of a floor plan of a building, perhaps filled with smoke. Again, this is a test of your ability to remember details. As mentioned in Chapter 11, Spatial Relations, the ability of a firefighter to read a floor plan is crucial, as you may someday find yourself making your way through hallways and rooms filled with smoke. When presented with a floor plan, you will want to note the location of potential hazards and dead ends you may be asked the placement of exits or smoke alarms or where to position a ladder for rescue. 

Facilities where EVs are charged or stored should be protected from fire. The same fire protection technologies used few conventional vehicles should be used for EVs. In charging facilities, sprinkler systems can be used because chargers are designed to withstand the water exposure that a sprinkler system would cause. Smoke alarms and ultraviolet/infrared detectors are recommended for EVs, just as they would be for conventional vehicles. 

Smoke alarms contain a weak source made of Americium-241. 

The installation of gas sensors to warn of gas leaks and the attendant risk of explosion is increasing in the developed world, especially in situations where bottled gas is stored, for example in caravans, trailers and boats. In the UK it is becoming commonplace to install them in homes along with smoke alarms. 

Simple buzzers are made in very large numbers for all types of tone generators used in phones, smoke alarms, toys etc. The device comprises a poled PZT disc cemented to a thin metal disc which vibrates at the frequency of the applied voltage. 

Wires and cables used for fire-alarm systems and smoke alarms must comply with the above and one of the following ... 

Am), which sends a stream of radiation to a detector. The smoke alarm goes off when this stream is interrupted by smoke—or steam, which is why smoke detectors in the kitchen can have an annoying habit of going off even when there isn t a fire. But smoke detectors have saved an impressive number of lives, so resist the temptation to disable the annoying smoke detector and provide the kitchen with better ventilation instead. 

If a building fire occurs, a smoke alarm sounds with probability 0.9. The sprinkler system functions with probability 0.7 whether or not the smoke alarm sounds. The consequences are minor fire damage (alarm sounds, sprinkler works), moderate fire damage with few injuries (alarm sounds, sprinkler fails), moderate fire damage with many injuries (alarm fails, sprinkler works), and major fire damage with many injuries (alarm fails, sprinkler fails). Construct an event tree and indicate the probabilities for each of the four consequences. 

The BioSentryTM Water Moiutoring System is an early warning system (EWS) that is intended to alert the user of potential harmful contamination, much like a smoke alarm alerts the homeowner of a potential household fire. It utilizes the described MALS technology to provide continuous, real-time moiutoring and classification of harmful pathogens in water. 

Prismatic batteries, such as those used in smoke alarms and alkaline flat-pack cycle lamp batteries are also removed at this stage. 

Industrial measuring techniques Control engineering (e.g. non-contact thickness gauging, level measuring) smoke alarm systems... 

---