Week 7 - Temperature Sensors

Temperature sensors are extremely important in modern life. Chemical engineering, modern medicine, and many other fields demand that the exact temperature be measured constantly. These sensors have to be extremely precise in order to maintain effectiveness. Specifically relating to BIM, temperature sensors are utilized to maintain a level of desired temperature for the inhabitants while also making the building energy and cost effectiveness. Temperature sensors have been a household item since the development of the mercury thermometer. These thermometers, or filled system thermometers, are filled with a liquid material with a high thermal expansion rate. This material then expands with the increase of molecule movement, or increase in heat. This sensor is ultimately reading and reacting to the increase or decrease in molecular movement, which controls how the liquid expands or contracts. (Middleton 1966)

The most commonly used temperature sensor today would be thermocouples. These types of sensors monitor temperature using electricity, like many modern sensors. This sensor is comprised of two different conductors in long, tube-like fashion. These conductors are placed a different temperatures, one location being the reference temperature, and the next being the location in which the temperature is trying to be measured. The differences in temperature between the reference point and point of interest produces a voltage which is then analyzed by a computing system to then provide the temperature at a certain point. These systems are inexpensive and require no external power, much like a filled system thermometer, which makes them highly popular. However, thermocouples are not extremely accurate and should not be used when extreme accuracy and precision is required. (Babadi 2011)

A pyrometer is another type of temperature sensor which utilizes a different approach from both thermometers and thermocouples. Radiation pyrometers measures the radiation of a given light, either visible or infrared, and then this this radiation heats an internal thermocouple to create a voltage. These types of sensors are used in non-contact situations.  (Stein 1994)

Temperature sensors are invaluable to BIM, as well as many other fields. Creating comfortable and cost-effective buildings require that the temperature be monitored and maintained at all times. These devices are not as simple as many people think however. And in order to utilizes them properly, one must understand what these sensors are actually doing.

References

Babadi, S. (2011, April). Sensors and their Applications. In 10 th Research Seminar Series Workshop.

Middleton, W. E. K. (1966). A history of the thermometer and its use in meteorology (p. v). Baltimore, Md.: Johns Hopkins Press.

Stein, A. (1994). U.S. Patent No. 5,308,161. Washington, DC: U.S. Patent and Trademark Office.

Comments

Melanie- Great post outlining the current state and limitations of motion sensors. I am curious how much these will actually advance. Do you believe that motion sensors could be improved enough to be utilized for other systems? I agree that the lighting system is one of the few systems in which motion detectors are effective and not annoying. Even then, motion sensors can become aggravating if the lights keep turning off.

Nameta- I really enjoyed that you brought attention to the fact the humidity is just as important as temperature in terms of indoor air quality. These types of sensors are very important to maintain a healthy indoor space as well as a comfortable one. BIM aims to create the most effective building and being able to monitor the humidity is extremely important.