Ninshuti - Group A - Pressure Sensors

A pressure sensor determines pressure from gases or liquids. In addition to pressure, pressure sensors can also measure fluid/gas flow, speed, water level and altitude. For measurement of pressure, the application is usually in the field of weather instrumentation, aircraft and other industries where the equipment has pressure functionality. For altitude measurement, this is most applicable for rockets, aircraft, satellites and others. 

Pressure sensors are used to determine pressure changes between altitudes. A pressure sensor can also act as a transducer. “The pressure is sensed by mechanical elements such as plates, shells, and shells that are designed and constructed to deflect when pressure is applied.” [1] This is how pressure is converted into a physical movement. This movement is then transduced to create an electrical output.

The main types of sensing elements are Bourdon tubes, capsules and bellows. All these provide a large displacement when a pressure is applied which is useful for some electrical sensors that require a significant displacement. There are different types of sensors. For mechanical pressure gages, the motion applied can be read by a dial or pointer. In the case of electromechanical pressure sensors, the sensors convert the applied pressure into an electric signal.

Pressure sensors have evolved in the last few years. Touch screen devices are commonly used in smart phones. When a pressure is applied by the finger, the sensor determines where it has been applied and an electrical signal is generated which then informs the processor. Pressure sensors can also be used in the biomedical industry in digital blood pressure monitors and ventilators, “pressure sensors are needed to optimize them according to patient’s health and his requirements.” [3] For airplanes, these sensors are used to maintain a balance between the atmospheric pressure and control systems of the airplanes.

Pressure sensors have definitely evolved during the last century from their use in steam engines to their application in biomedical engineering. When it comes to Intelligent Buildings, sensors are also becoming more popular: the security of a home can be improved by allowing access only by finger or hand prints and other methods.

Comments:
Ian: Great post! We usually don't realize how much sensors have become part of our lives especially light sensors and toilet sensors. I liked that you looked at their advantages as well especially when it comes to energy efficiency.

Tyler: Great post as well! I didn't know that much about temperature sensors. Like Ian's post, you talked about the energy that is saved from using these temperature sensors. This also ends up saving money from utilities. 

Sources:

1.      Bicking, Robert E. "Fundamentals of Pressure Sensor Technology." Sensors Magazine. N.p., 1 Nov. 1998. Web. <http://www.sensorsmag.com/sensors/pressure/fundamentals-pressure-sensor-technology-846>.

2.      "The Pressure Sensor." Sensorland. N.p., n.d. Web. <http://www.sensorland.com/HowPage004.html>.

3.       "Pressure Sensors." Engineering Garage. N.p., n.d. Web. <http://www.engineersgarage.com/articles/pressure-sensors-types-working>. 

Group A: BIM Tools and Parametric Modelling

This chapter provided a basic overview of how BIM defers from previous CAD modeling techniques. With BIM systems, a set of predefined building cases are provided from which the design can modify for their own use and needs. Compared to earlier CAD modelling where a shape had to be defined and given properties, with BIM systems, an object can update itself as the context changes. This is described as the object’s behavior. The level of 3D modeling required, instead of modification of objects, is what differentiates different BIM practices.

In the beginning of 3D modelling, two methods competed which are B-rep (boundary representation) and CSG (Constructive Solid Geometry). With B-rep, shapes were created and Boolean operations were used to overlap, subtract the shapes and other functions. This is called rendering. Extrusions and rotations of 2D models could be used to produce 3D models. With CSG, shapes were described using text strings. The two methods competed for years but modern “BIM models incorporate both methods.” (Page 34) CSG is used for editing while B-rep is easier for visualizing and measuring.

As modelling evolved from CAD into parametric modelling, one factor that was included in this evolution is the “recognition that multiple shapes could share parameters.” (Page 37) The advantage to this is that if the size of the wall changes, the other shapes in contact with the wall should be able to update to accommodate for the change in the wall size. This has definitely made design easier and more practical: designing a building with thousands and thousands of objects without a system that allows for low-level automatic editing would time consuming. It also makes the model more accurate if the designer can trust that a change in one object will not lead to a gap/error in another part of the building.

In addition to discussing why BIM is important and the advantages of parametric modelling, this chapter compared different BIM systems and discussed their strengths and weaknesses. I was interested in the Revit and Tekla portions. Tekla is a program that I have never used but was exposed to on a previous coop. The program can be used for steel fabrication and allows for editing in the form of trimming members for steel connections. Over time, the program has evolved to include the design of precast concrete, reinforced concrete, and timber. Its main strength is that it is able to model structures that incorporate a wide range of building materials.

Through this chapter I was able to acquire a deeper understanding of how far 3D modeling has come from just using extrusions to create 3D-shapes, to being able to monitor the development of different shapes in a building. 

Comments:

Matt:
Great post Matt! It's great that you have experience with Revit and therefore are able to understand most of the handbook (which is more than I can say for myself). Your pictures are great as they explain in part what the handbook outlined. Maybe you can discuss other programs that were mentioned in the handbook such as ArchiCAD, Tekla and others. How do these defer from Revit in terms of BIM capabilities, in your opinion?

Stephen:
My coop was also similar in that there seemed to be a transition from from Autocad to Revit. There were two BIM modelers, their job required them to be Revit experts. They were also great at Autocad because most of the engineers were only proficient in Autocad and if they wanted to explain a connection, they would draw it in Autocad and send it to the BIM modelers. 

Michael:
I agree that this chapter makes it seem really important to become more proficient with Revit. Like you, reading this helped me understand why BIM programs are so useful.