This week I will be at a physics conference in Edinburgh.
Non-equilibrium Physics
of Self-Assembly: from Viruses to Nano-containers
Monday 13 Nov
– Friday 17 Nov 2023
https://www.icms.org.uk/Non-
Go to the lab on Monday, November 13 and work on the Angstrom experiment. Complete the 13 tasks in the “Assignment” section in the Matlab program “PlotAngstromExpPeriod60.mlx”.
Collect data using a minimum of 3 thermistors. I recommend using 5 thermistors. When you record data, be sure to first measure the temperature along the rod when it is at room temperature and after recording the sinusoidally varying temperature. You need to know what room temperature is and if there is any variation along the rod.
I uploaded more code to Github. You can write your own code, or use mine. There are several versions, as I incrementally updated the code. In brief,
The following Arduino code processes 4 and 6 thermistors, respectively. Each has one thermistor dedicated to controlling the TEC and then have 3 (5) thermistors for measuring the temperature along the rod.
SerialTestNov1a.ino (3 thermistors for measurement)
SerialTestNov8a.ino (5 thermistors for measurement)
The following Matlab GUI and Arduino code control the Angstrom experiments for 3 thermistors:
TEC_V7.mlapp
SerialTestNov1a.ino (3 thermistors for measurement)
The following Matlab GUI and Arduino code control the Angstrom experiments for 5 thermistors:
TEC_V9.mlapp
SerialTestNov8a.ino (5 thermistors for measurement)
The following Matlab GUI and Arduino code automatically sweeps through the periods for the Angstrom experiments for 5 thermistors:
TEC_V10.mlapp
SerialTestNov8a.ino (5 thermistors for measurement)
There are comments in the code that explain its use.
The following Matlab code analyzes the data for 3(5) thermistors and fits it to the Angstrom model. The assignment is include in these Matlab files. The code assumes a single period of the sinusoidal temperature variation. I suggest duplicating the code and saving it as a separate file for each of the periods you measure, e.g. 1, 2, 3, 4 minutes per period.
PlotAngstromExpPeriod60.mlx
(3 thermistors for
measurement)
PlotAngstromExp5TPeriod60.mlx (5 thermistors for measurement)
Below is raw data from an experiment I ran. The data file is
temperature_data_20231110_174421.txt
and is on Github. The largest signal is from the TEC. The other 5 are spaced at ½ inch intervals along the rod. Notice the phase shift and decrease in amplitude, I ran the first period (1 minute) for 20 cycles to make sure that the transients had died out. I ran the second period (2 minutes) for 10 cycles as the rod had a lot of stored heat in it after the first period and so it only takes a few cycles to reach steady state. For the analysis you only need to fit 3 – 4 cycles. Only use steady-state data for fitting.
