Donahue - Group D - Flow Sensors

Flow Sensors

The topic of flow sensors happens to be an extremely broad one in the sense that there are countless types of flow sensors. And each type of sensor can perform different functions based on the measurement goal/task. A broad definition of a flow sensor can be expressed as a device that measures the rate of flow of a fluid. The particular type of fluid is again specific to the application or function.

As mostly civil engineers, we hear “fluid” and “fluid flow” and immediately think to our Fluids course, where we measured and analyzed the fundamentals and rates of water flow across a system. And this system was most usually a pipe. However, this is a very specific study in this area. In the process of completing this post, I’ve encountered some other very interesting, different, and innovative applications that use flow sensors. In an effort to provide new information, I'll present two different, specific examples in this post. 

One example of a simple yet important situation is when there are flow sensors that are used in pumps in residential and commercial applications. The situation is when there is a sink pump that is below ground and in turn, below the city water main line. The used water flows from the sink, shower, etc. and is stored by the pump. The flow sensor analyzes the rate and volume of fluid that enters and once the pump reaches near capacity, an additional sensor translates to the pump that it requires emptying by pumping the stored water up to the water main line, how ever many feet is required. This flow sensor is extremely imperative to the proper working of the system as a whole and as to not let the pump over flow.

Another very interesting, yet specific, example I encountered was intravascular medical devices that act as flow sensors inside the body, which measure blood flow and pressure. Pressure sensors are a topic that Esther describes comprehensively in her post and those concepts mixed with flow sensors make up these medical devices. They can be strategically placed to measure the blood flow and pressure for veins and major arteries. Once these measurements are taken, it is advantageous to the doctor and patient because then specific medical treatment plans can be formulated. The flow and pressure measurements are taken in various placed locations in veins and arteries. They are then relayed to the main system and doctors can determine if any occlusion (or blockage) is occurring and if so, where. The measurements taken are recorded in resistance and inductance simultaneously by the circuit by using frequency separation. By using proportions as well as comparisons to healthy, theoretical system measurements, doctors can translate the flow sensor results and make accurate medical conclusions. This is absolutely astonishing, considering the small size these sensors must be designed for use and accurate application.

Comments:

On Esther's:
Great post Esther! You did a really nice job explaining pressure sensors and discussing the many types, applications, and functions. I particularly liked the paragraph in which you discussed pressure sensors being used in smartphones. Touch screen pressure sensors on smartphones are used everyday by most of us, yet I didn't think of it when first thinking about pressure sensors. Like I mention in my post, I just immediately think of fluids and measuring flow and pressure. Really good job discussing so many types!


On Audrey's:
Audrey, good job on your post. It was well organized and well written. You did a great job presenting a comprehensive range of types of temperature sensors and you explained them in detail. By first presenting and defining everything and then going into the technical details, it makes for an easy to read and easy to follow post. Good job!

Resources:

[1.] Intravascular Pressure and Flow Sensor. Paul T. Feld. Patent US5873835. 29 Apr. 1993. Print. 13 Feb. 2014. Web.

[2.] Kolin, Alexander, Julius Grollman, Richard Steckel, and Harold Snow. "Determination of Arterial Blood Flow by Percutaneously Introduced Flow Sensors in an External Magnetic Field." Proceedings of the National Academy of Sciences 68.1 (1971): 29-33. Web. 13 Feb. 2014. <http://www.pnas.org/content/68/1/29.full.pdf>.