Events Log

November 6th - Data Analysis

The data, specifically from the on-board temperature sensor, was questionable, so we decided to do some calculations to determine whether or not the temperature of over 40 degrees C (the sensor maxed out at 40 C because of the way it scales data) was plausible. We (Marc, Alex, Neal, Evan.. kind of) calculated that all of the batteries together would produce 1W of heat inside of the box. Assuming the box acted as a "black body", the temperature inside of the box would be approximately 3 degrees warmer than outside. Then, the box would radiate 3W to the outside. We found this by using the Stefan-Boltzmann formula. Looking at the graph, the temperature inside the box was around 3 C warmer than that of the lake, so we found that it's certainly possible that the batteries created the difference in temperature, or were at least a major variable.

As for the ridiculous temperature spikes during the day-time, we currently believe that to be because of the "greenhouse effect" taking place within the plastic box.

Data Plot:

(3/22/16 - Further Data Analysis)

We compared our data from the sensor with air temperatures from Weather Underground, which we know for sure is accurate (see table below.)

Lowest water temperature correlates with the lowest outside temperature at night - good.
On clear, dry days, the surface of the water warmed up more than the bottom ### Is this normal ??? ###.
The temperature inside the box has a direct correlation with cloud cover.
Question - on the last day, it is unclear to us why the lake continues to warm up, even though the outside temperature is consistently colder than the lake. ### What in the world is happening here ??? ###
Idea - fix the light sensor in such a way to detect cloud cover. (Different resistor?)

November 6th, 2015

Retrieved sensor from lake, brought it back and took the data.

November 2nd, 2015 - Yerkes Pier

We set up the sensor again, with a OneWire sensor on top of the lake, a OneWire sensor on the bottom of the lake, and a temperature sensor on the Arduino in the box.

October 19th, 2015 - Yerkes Pier - Recovery

The sensor was recovered with no damage and was still running. After reviewing the data the on board sensor(red) needed more calibration in order to make it more accurate in its measurements. The system was recovered around 16:00

October 14th, 2015 - Yerkes Pier

The sensor was set up by the second pillar on the east side of the Yerkes pier.

Blue sensor was attached to a floating log (sensor is about 5mm below water surface)
Green (duct tape) sensor was attached to a brick and hanging down, about 20cm above the lake bottom.
System was started about 16:30
Test: Friday, Oct 16th 14:41-14:45

October 13th, 2015 - Engine Room

Sensor system was set up in the heating room, close to the window next to the door:

Blue sensor was attached to the steam return pipe
Green sensor was ~10cm out the window.
Sensor system was started at 12:10

October 8th, 2015 - Yerkes Roof

Adam created an enclosure and power supply for the sensor, using five D-cell batteries like before. Later we (Evan and Marc) wiped the old data off of the sensor by writing an Arduino program which set all addresses on the chip equal to zero (EEPROMclear.ino uploaded to filemanager under stars/Research/Environmental/Programs/151008). We set the Arduino up to take data in 90 second intervals. We then loaded the "EEPROMwrite" Arduino script and set up the newly housed sensor on the roof of Yerkes. (Note: the sensor began taking data at 18:40.)

August 4th, 2015

We placed the temperature sensor in the student office with a power supply of five D-cell batteries. The power supply ended up lasting approximately five days. We placed one temperature sensor outside and one inside. The third temperature sensor was on the board which we believe malfunctioned.

August 21st, 2014

We recovered the sensor from the Yerkes Pier, but the data showed that it only collected for 2 hours.

We determined that the power must have faded due to using a used battery.

The sensor was replaced at 17:30 with a new 9V battery.

Winter 2013-2014

April 24 2014
- Measurement Started 17:15
- Sensors:
  - 1: DS Temp Sensor Pin 3 - On the side of the wall, 2 feet from ground - Scaling is Temperature(C) * 10
  - 2: Onboard TMP Temp Sensor - Scaling is Voltage from 0.5-1.0V (0-255)
  - 3: Light Sensor - Scaling is Voltage from 0-4V (0-255) Resistor is 1000 Ohm
  - 4: DS Temp Sensor Pin 4 - On the ground in the Gras - Scaling is Temperature(C) * 10
March 13th 2014
- Measurement started on March 6th around 5 pm
- Light Sensor Resistor was 3300 Ohm in the window inside the office.
Temp 1 was on the building, Temp 2 was underneath the snow, and then the snow melted. Temp 3 was on the Arduino inside the office.
- The sensors were in Marc's office.