Category Archives: Group 8

Group 8 Project Data: Microwave Radiation

EXPERIMENT SET-UP:

Readings were taken at three distances (1 cm, 30 cm, and 60 cm) from the microwave oven door as well as from the right side (magnetron) of the oven.

 ExpSetUp

TECHNOLOGY USED:

Our data was collected with entirely with an RF Meter: with it, we tested the EM field strength around different microwaves at various locations around campus. The only other technology used in this experiment were the microwaves tested, which were all of varying models and ages.

DATA COLLECTION OVERVIEW:

We collected our measurable data as a team, with all three people assessing the qualitative variables before beginning measurements, and then one person recording data, and two using the RF meter in conjunction with the microwave to collect data. We allowed the microwave for ~30 seconds before starting to collect data to make for a more consistent readings from each distance.  We first observed the average value at each distance.  This required us to be subjective–since the average value switched as the RF meter collected data, every second or so, two people observed the average values for about 10 seconds before deciding an approximation where most of the values fell.  We then switched to measuring the maximum average, a value that stood constant on the RF meter.  We repeated this process at each distance from the microwave.  We of course switched roles periodically in order to give each member of the group a better understanding of the overall process!

We got to this streamlined process through trial and error, and toggling with the RF meter, whose manual is not extremely comprehensive.  We had to test measuring from different axes and also realized that we needed to measure the radiation in the general vicinity of the microwave before we measured for microwave radiation, so that we had an idea of the baseline of EM fields in the area.  We also had to toggle with measuring values on different settings.  While we began measuring only maximum average, we realized this did not give a sufficient idea of the radiation emitted on average.  Furthermore, if the RF meter caught a signal from something like a cell phone receiving a text, that outlying measurement would appear on the meter rather than the measurement from the microwave.  We decided to use both average and maximum average measurements to get an idea of how much radiation was generally emitted, as well as how much could potentially be emitted.

We also collected data by researching the safety standards of microwaves.  This data will help us understand what our values mean during analysis/conclusions.  We found that the International Electrotechnical Commission has set a standard of emission limit of 50 Watts per square meter at any point more than five centimeters from the oven surface. The United States Federal Food and Drug Administration has set stricter standards of 5 milliWatts per square centimeter at any point more than two inches from the surface. Most consumer microwaves report to meet these standards easily. Further, the dropoff in microwave radiation is significant with the FDA reporting “a measurement made 20 inches from an oven would be approximately one one-hundredth of the value measured at 2 inches.”

DATA COLLECTING CONDITIONS:

The conditions under which our data was collected were simply the conditions of the microwaves habitats: some were found in secluded kitchens without much EM feedback from its surroundings (before testing each microwave we made a note of the general, ground-level EM reading in the vicinity so we could adjust and compare microwaves after taking that initial radiation into account), and others were found in areas where wi-fi signals and cell phone usage really bumped up the ground-level readings, and requiring us to adjust how we understood the data accordingly,

UNITS:

  1. Distance from the microwave (cm.)
  2. Power of Microwave, found on microwave label (Watts)
  3. Radiation (µW/m^2)

DATA TABLES:

1) Preliminary Observations

Sample #

Location

Brand

Wear and Tear, Year?

Radiation Off

M1

Strong Kitchen

GE

MSES1139BC03

June 2011

No major wear and tear

AVG: 0.00

MAX AVG: 0.00

M2

Retreat

LG Orbit

LRM1230W

December 2004

In good shape

AVG: 0.00

MAX AVG: 0.00

*but when measuring not on avg., values did appear

M3

Noyes Dorm Room

Microfridge with Safe Plug

N060203077

February 2006

Squeaky noises

AVG: 0.00

MAX AVG: 0.00

M4

UpC

Amana Commercial Microwave

RFS11MP2

February 1999

AVG: 17.7 µW/m^2

MAX AVG: 18.4 µW/m^2

M5

South Commons Senior Housing

Emerson MW8999SB

March 2013

New condition

AVG: 0.00

MAX AVG: 0.00

2) Average EM Radiation Values

Sample #

Power (Watts)

EM Radiation from Front (1 cm)

EM Radiation from Front (30 cm)

EM Radiation from Front (60 cm)

EM Radiation from Magnetron (1 cm)

EM Radiation from Magnetron (30 cm)

EM Radiation from Magnetron (60 cm)

M1

1,600 W

300 µW/m^2

475 µW/m^2

350 µW/m^2

800 µW/m^2

300 µW/m^2

125 µW/m^2

M2

1,200 W

275 µW/m^2

200 µW/m^2

250 µW/m^2

700 µW/m^2

1.00 mW/m^2

300 µW/m^2

M3

700 W

270 µW/m^2

100 µW/m^2

90 µW/m^2

600 µW/m^2

125 µW/m^2

130 µW/m^2

M4

1,250 W

1.5 mW/m^2

800 µW/m^2

300 µW/m^2

200 µW/m^2

350 µW/m^2

300 µW/m^2

M5

900 W

300 µW/m^2

275 µW/m^2

120 µW/m^2

250 µW/m^2

80 µW/m^2

30 µW/m^2

3) Maximum Average EM Radiation

Sample #

Power (Watts)

EM Radiation from Front (1 cm)

EM Radiation from Front (30 cm)

EM Radiation from Front (60 cm)

EM Radiation from Magnetron (1 cm)

EM Radiation from Magnetron (30 cm)

EM Radiation from Magnetron (60 cm)

M1

1,600 W

628.3 µW/m^2

662.5 µW/m^2

508.8 µW/m^2

1.1 mW/m^2

571.3 µW/m^2

123.4 µW/m^2

M2

1,200 W

1.2 mW/m^2

282.9 µW/m^2

482.9 µW/m^2

1.8 mW/m^2

1.5 mW/m^2

1.1 mW/m^2

M3

700 W

457.7 µW/m^2

182.2 µW/m^2

169.1 µW/m^2

726.3 µW/m^2

252.2 µW/m^2

162.4 µW/m^2

M4

1,250 W

2.5 mW/m^2

1.7 mW/m^2

1.6 mW/m^2

372.0 µW/m^2

250.0 µW/m^2

477.9 µW/m^2

M5

900 W

798.2 µW/m^2

488.8 µW/m^2

149.6 µW/m^2

209.4 µW/m^2

92.3 µW/m^2

97.9 µW/m^2

DATA GRAPHS

1) Average Radiation from Front

Screen Shot 2014-02-17 at 9.35.17 PM

2) Average Radiation from Magnetron

Screen Shot 2014-02-17 at 9.35.06 PM

3) Maximum Average Radiation from Front

Screen Shot 2014-02-17 at 9.34.50 PM

4) Maximum Average Radiation from Magnetron

Screen Shot 2014-02-17 at 9.34.35 PM

 

Emma Foley; Hunter Furnish; Hannah Tobias

(G8 Project Abstract) How to Cook Yourself: Radiation and Microwaves

Group 8 will measure the amount of electromagnetic radiation that certain appliances give off.  We will test a variety of devices, but predominantly focus on and compare microwaves that differ in size, antiquity, and wear & tear.  We will use RF meters to measure the amounts of radiation given off and the Watts Up Pro to measure the amount of power used to identify any correlation between power and radiation.  We will measure radiation with respect to distance from the microwave and direction of the RF meter in the surrounding electromagnetic field and compare our findings to traditional beliefs about microwave radiation.

 

Hunter Furnish; Emma Foley; Hannah Tobias