README.md

# Introduction to Sensors and Data Analysis (Fall 2018)

## Lab #5 Mass Measurement Device with Cantilever beam

# Mass measurement contest



![Mass measurement cantilever](./contest_diagram.png)

*Figure 1: Diagram of cantilever with unknown mass in position 2 out of 3 total
positions. Measure changes in the natural frequencies to determine mass of
object.*

In the mass measurement contest, you will use natural frequency shifts to
determine the mass of an object. There are three locations you can mount the
object as seen in Figure 1, where the object is mounted in position 2. The
experimental procedure only involves measuring natural frequency with the mass
mounted in different positions. You can create an *engineering model* as we will
do with experimental results from Ghatkesar *et al.* 2007
[\[1\]](./ghatkesar-et-al-2007_higher-mode-mass-sensors.pdf), as described in
section 2.

You can use the modal analysis in **Ansys**
[\[2\]](https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/main_page.html)
and apply a point mass to get predicted changes in natural frequencies. This
will create a table of values for your given cantilever for known masses for
*interpolation* as described in section 3.

**Rules of Contest**

1. The masses must not leave the lab

2. You cannot mount other known masses to the cantilever

3. You must report your uncertainty in your mass measurement to enter the
competition

4. You must report your serial number "TJM 01-TJM 12" to enter the competition

6. You may use the following tools and software: strain gage or accelerometer
(not both), calipers, Ansys, Labview, Python, Matlab, and Excel

**Winners of the contest**

There will be two sets of winners for the contest:

1. Lab group with the most accurate mass measurement calculated with
$A=|m_{reported}-m_{actual}|$

2. Lab section with the most precise mass measurement calculated with
$P=\sum_{i=1}^{N}(m_{reported}-m_{actual})^2$

Where $A$ is the accuracy, $P$ is the precision, $m_{reported}$ is the reported
mass from your experiment, and $m_{actual}$ is the actual mass of the object,
and $N$ is the total number of lab groups in a section. The group and section
with smallest A and P, respectively will win prizes. The prizes are as such

1. ** \$100 cash prize** put into your student accounts ($50/group member for
group of 2)

2. **Donuts/cookies** brought to your lab section

**Lab #5 report** should include details of the following

1. Your design of experiments

2. Your measured results

3. Your predicted results from Ansys

4. Your final calibration process for measuring a mass based upon natural
frequency changes