Energizer, yes the battery company itself, tells us that all batteries are prone to failure. 10 year smoke alarms run the risk of "premature expiration", in which the battery dies before the stated 10 years

Cite (APA): E. (n.d.). Potential Problems Surrounding 10-Year Smoke Alarms With Sealed Batteries. Retrieved from https://www.cga.ct.gov/2015/psdata/tmy/2015SB-01012-R000303-Energizer%20Duracell-TMY.PDF

According to the article from 2012- 2016, with fire alarms operating on battery's, 51% of the time the smoke alarm is either missing a battery from the alarm or the battery is disconnected. This shows that there is a pretty big problem when it comes to how fire alarms receive power and how they fail using a battery.

Cite (APA):

Ahrens, M. (2019, January). Smoke Alarms in U.S. Home Fires. Retrieved September 21, 2020, from https://www.nfpa.org/-/media/Files/News-and- Research/Fire-statistics-and-reports/Detection-and-signaling/ossmokealarms.pdf

This smoke detector patent from 1989 contains visuals and information on how it works. Still pertaining to current times, this patents shows how the layout of a household/building is directly connected to the effectiveness of the smoke detector and failures that may occur in such cases.

Cite (APA):

US4871999A - Fire alarm system, sensor and method. (n.d.). Retrieved September 22, 2020, from https://patents.google.com/patent/US4871999A/en

Though smoke detectors are meant to go off when smoke is present, they will also tend to go off on accident in the event that it is full of dust or present around other strong fumes.

Cite (APA):

Why is my Fire Alarm Going Off? (n.d.). Retrieved October 05, 2020, from https://www.covesmart.com/blog/fire-alarm-going-off-what-can-trigger-a-smoke- detec

Circuits are usually being overlooked when a smoke alarm is inspected. Wires and resistors are overlooked at times and will result in system failure if looked after incorrectly.

Cite (APA):

Kaiser, L. (n.d.). Causes and Cures for Recurring System Trouble Signals (Video). Retrieved October 05, 2020, from https://www.orrprotection.com/mcfp/blog/recurring-fire-system-trouble-signals

Ionization sensors have two plates in a chamber. Between these two plates is a voltage, if an electron is moved out of place, ionization occurs. This then makes the fire alarm go off. Ionization sensors are more responsive to fires so, they are mainly used in residential buildings.

Cite (APA):

What is an ionization smoke alarm – How does an ionization smoke detector work. (n.d.). Retrieved February 03, 2021, from https://www.firstalert.com/what-are- ionization-smoke-alarms/

Photoelectric Sensors have a light beam either that is visible or infrared.

There are two types of Transmitters. One is just a transmitter that transmits the light and the other is a transmitter and a receiver. The Transmitter/receiver model or (Reflective model), shoots a beam of light and when smoke travels through the light, it is reflected off the smoke and the receiver receives the light, and sounds off the alarm.

Cite (APA):

Detection based on "LIGHT"WHAT is a PHOTOELECTRIC SENSOR? (n.d.). Retrieved February 03, 2021, from https://www.keyence.com/ss/products/sensor/sensorbasics/photoelectric/info/

Heat Sensors are more for protecting property and not protecting human life. Heat sensors have a bimetallic strip or low fusing alloy. Heat sensors also have a rate of rise components and can either be mechanical or electrical. With the rate of rise, when the temperature starts rapidly increasing by about 12°F – 15°F per minute, the alarm is activated. There is also a fixed temperature head sensor, which can alert when a temperature exceeds the fixed temperature point.

Cite (APA):

(1) User, S. (n.d.). Heat detectors. Retrieved February 05, 2021, from https://nationalfireinc.com/alarm-systems/heat-detectors.html

(2)Heat detector alarm. (n.d.). Retrieved February 05, 2021, from https://www.getkisi.com/guides/heat-alarm