1. 8/18/2015, Daniel Ruatta
Project Proposal: ​LM­35 temperature sensor attachment for more accurate temperature readings
Background
This project is being undertaken so that we can more accurately measure the temperature of the OD
(Optical Density) sensor. The problem with our current setup is that our temperature reading comes from a
considerable distance away from the OD sensor, and this does not provide us with a strong enough
correlation between OD and temperature.
Our options for more accurate temperature measurement are LM­35’s (Temperature Sensors), NTC­102’s
(Thermistors), or P13R­001’s (Thermocouples). Diana and I have decided that LM­35’s would be the most
effective way to measure temperature within the AADEC, due to their cost ($0), availability (we already have
them), and accuracy (+/­ 0.25 *C). Note that this accuracy measurement can be found in the datasheet of
the LM­35.
Objectives
­ Install the LM­35 as close to the OD sensor as possible, given the amount of electronics already
around it
­ Link the temperature sensor to the arduino on the temperature board
­ Add Arduino software that will log the sensor’s output along with a test harness
­ Use an IR thermometer to measure the temperature of the box at least 3 different times, comparing
the IR thermometer to the LM­35 temperature readout each time
­ Create a final write­up explaining the details of the experiment, any implementation changes that
were necessary (with pictures), what other temperature sensor datasheets were looked at, and how
much of an improvement was made to our temperature reading
Scope
The end result of this project is a more accurate temperature reading that will provide us with a stronger
correlation between OD and temperature.
I have already ordered LM­35 Temperature sensors from Texas Instruments. I recommend we use the
LM­35 because its accuracy (+/­ 0.25 *C) is very good for its price ($0), whereas the accuracy of the
NTC­102­R is unclear even given the datasheet and the accuracy of the P13R­001 is 1.5 *C. If accuracy
down to +/­ 0.1 *C is needed then I would recommend thermistors from
http://www.omega.com/prodinfo/thermistor.html​. These will range anywhere from $15 ­ $100. My next step
will be to install one of the LM­35’s and connect it to the Temperature board. This will allow the arduino to
read the data coming from the LM­35. There are video instructions on that here
https://www.youtube.com/watch?v=B7oc9Xb_RSg​ I will then write software that allows for logging of the
sensor data based off of the logging code that already exists in the SVN repository. Finally, I will test this
software to ensure successful logging of the sensor data.
Budget
­ LM­35’s: $0
­ Wire: $0
Total: $0

2. Monitoring and Evaluation ​(Note that this is assuming the use of the LM­35)
­ 8/20 at 5pm, I will have the temperatutre sensor installed and connected to the Arduino. I will also
have the revised project proposal in the SVN in the directory Hardware/Temperature/LM­35
Installation
­ 8/27 at 5pm, I will have the software for reading and logging the sensor data written
­ 9/3 at 5pm, I will have the tested the software and have data being logged from the temperature
sensor
­ 9/10 at 5pm, I will have taken three different temperature readings (22 *C, 29 *C, and 37 *C) with
both the LM­35 and the IR thermometer, and compared this data to the temperature reading that
automatically comes from the AADEC, to determine how much of an improvement has been made.
­ 9/17 at 5pm, I will have the write­up of the project complete
Supplemental Documentation
Image of where I will be attaching the LM­35:
LM­35 Datasheet: ​http://www.ti.com/lit/ds/symlink/lm35.pdf
NTC­102­R Datasheet:
http://www.murata.com/~/media/webrenewal/support/library/catalog/products/thermistor/ntc/r44e.ashx
P13R­001 Datasheet: http://www.omega.com/toc_asp/frameset.html?book=Temperature&file=tc_colorcodes