Tag Archives: radiation

Group One’s Data: Radiation on Vassar’s Campus

For our research project, we attempted to measure the counts of radiation in academic buildings around campus using a Geiger Müller (GM) tube attached to a LabQuest 2. We were also interested in seeing if the radiation levels observed correlated with the ages of the buildings tested. This is an important type of testing to do, as over-exposure to radiation, especially $\gamma$ particles, which are high energy photons without mass, can lead to negative results. These can include radiation poisoning, as well as cancer and other genetic mutations. To conduct our research, we walked around each of the buildings at a steady pace for 5 minutes, moving the GM tube from side to side. When there was an indication of possible radiation contamination, the tube was focused on that area to determine if there was a higher radiation count. For example, there are areas in Olmstead that have radiation warnings on the door, and we stopped and waved the Geiger tube there for a considerable amount of time to test for any radiation contamination that may have been leaking through.

Figure 1. The apparatus used for recording radiation. The GM tube is located on the right. It is a gas filled detector, which functions using a low-pressured inert gas to amplify the signal of any radiation entering the tube. Radiation passes through the gas in the device and the molecules in that gas are ionized, leaving positive and negative ions in the chamber. These ions move toward separate charged sides (the anode and cathode), creating a current which is then sent through the wire to the LabQuest 2 Device to be measured and recorded. Each $\alpha$ , $\beta$ , or $\gamma$ particle entering the tube is measured as one “count” of radiation.

	Average (Counts/0.1 Min)	Max (Counts/0.1 Min)	Age
Aula	1.94	5	1890
Blodgett Hall	1.54	4	1929
Chicago Hall	1.86	6	1959
Kenyon	1.28	5	1933
Library	1.98	6	1905
Mudd Chemistry	1.16	5	1984
Old Observatory	1.62	5	1865
OLB	1.34	4	1872
Olmstead	1.36	5	1972
Rocky Hall	2.38	6	1897
Sanders English	1.94	4	1909
Skinner Hall	2.44	7	1932
Swift Hall	1.58	4	1900
Background	1.32	3	–

Figure 2. Table of Average and Maximum radiation counts as compared with the age of the building. As read from left to right, the columns are labeled as (1) the buildings tested, with “Background” representing the data we collected between buildings to determine an average radiation level, (2) the average count of radiation observed in each building (per 0.1 of a minute over the course of 5 minutes), and (3) the highest amount of radiation observed in each building, and the age of the buildings that we observed. We initially hoped to be able to distinguish $\alpha$ , $\beta$ , and $\gamma$ radiation from each other, but upon further review, we determined the only types of radiation we were likely to detect were $\gamma$ and high energy $\beta$ . This is because these travel further from their source than $\alpha$ , and are generally emitted by the same type of material.

Figure 3. The average radiation counts compared with the age of the buildings. A trend line has been plotted to show the direction of correlation.

Figure 4. The maximum radiation counts compared with the age of the buildings tested. A trend line has been plotted to show the direction of correlation.

We plotted the above data observed in two graphs (Figures 3 & 4). Figure 3 shows the average radiation levels by the year that the building was built, while figure 4 shows the maximum radiation level observed by the year the building was built. As you can see, there is little to no association between the variables in either figure (figure 3: r=0.275, r²=0.076; figure 3: r=0.228, r²=0.052, where the “r” value indicates the closeness of correlation of the data, and the r² value indicates the percent of data that fits within that correlation).

The literature provided by Vernier, the makers of M tube and the LabQuest 2 device, states that expected background radiation levels should be between between 0-2.5 counts of radiation/0.1 min. Our average background radiation testing was within this range (avg=1.32 counts/0.1 min, max=3 counts/0.1 min). All of the average readings from buildings were also within this range (the highest average being taken in Skinner Hall: 2.44). With this information, we can conclude that Vassar campus is safe in terms of radiation levels.

Group 8 Project Data: Microwave Radiation

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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.

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:

Distance from the microwave (cm.)
Power of Microwave, found on microwave label (Watts)
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

2) Average Radiation from Magnetron

3) Maximum Average Radiation from Front

4) Maximum Average Radiation from Magnetron

Emma Foley; Hunter Furnish; Hannah Tobias

Group 8 Project Plan

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Group Roles: In order to effectively collect and analyze data while ensuring that each group member is a part of each step of the process.

Data Collecting: Data Recorder – Hannah; Data Collector 1 – Hunter; Data Collector 2 – Emma

Analyzing/Synthesis: Comparing Differences in Radiation – Hannah; Comparing Radiation to Power – Emma; Research on Safety of Radiation Levels – Hunter

Equipment Used: RF Meter (to test EM field strength around the microwaves at various locations), WattsApp (to measure the microwaves’ power), ~9 microwaves (of various models, ages, and conditions), TI-30X Calculator, Pencils, Notebooks

Science/Technology Involved: When the microwave is turned on, the magnetron, an electron tube in the upper part of the oven, generates microwaves to excite molecules and heat the food. Despite protective measures to ensure as little radiation seeps through the microwave as possible, such as the metal behind the door and the metal walls meant to reflect the radiation, absorption and leakage occur nonetheless while the microwave is on. These waves penetrate past the microwave, exciting molecules, to generate an electromagnetic field that emits some amount of radiation. The government has deemed this radiation safe to the human body based on the Specific Absorption Rate (SAR), the rate at which our bodies absorb energy, but others disagree that this exposure is dangerous nonetheless.

The Watts Up Pro meter will also provide us with the technology to measure the power (watts) that each microwave uses to function. With this data we can track correlations between power, and the strength of the generated EM fields.

“Microwave Ovens,” Federal Office of Public Health, 2009. http://www.bag.admin.ch/themen/strahlung/00053/00673/03752/index.html?lang=en

Activity Plan: We will measure the strength of the EM field while a microwave is on and compare how different microwaves emit more or less radiation. Furthermore, we will test different sides and distances from a microwave to determine if the radiation is 1) stronger at a certain side of the microwave (in the front, or closer to the magnetron, for example) and 2) if the field drops off after a certain distance.

On Friday, February 7th, at 1:00 pm we will walk around to different dorms to determine the status of each microwave. We predict many of them will be relatively the same model, but if some seem much older or have a lot of wear and tear (for example, the front screen has a hole in them) we will collect data on those individuals to see if there is a correlation between age/wear and tear and EM radiation. We will also compare power output and radiation. We will record the power output labeled on each microwave to do so.

We will collect our data on Saturday, February 8th at noon. We would like to test different microwaves both provided by the college and those provided by MicroFridge. We hope to test multiples of each brand to ensure our results are consistent. We will use an RF meter to measure the strength of the EM field and use the setting “Max Average” to get an average measurement over the course of a few seconds of radiation emission. We will collect data in the following table:

Sample #	Location	Brand	Wear and Tear?
M1
M2
M3
M4
M5
M6
M7
M8
M9

Sample #	Power (Watts)	EM Radiation from Front (1 cm)	EM Radiation from Front (10 cm)	EM Radiation from Front (20 cm)	EM Radiation from Right (1 cm)	EM Radiation from Right (10 cm)	EM Radiation from Right (20 cm)
M1
M2
M3
M4
M5
M6
M7
M8
M9

After we have collected the data, we will compile research on various proposed safety levels of microwave radiation, and compare our findings.

Expected Outcomes: Our group expects to confirm the safety of standard consumer model microwaves in regards to the level of microwave radiation emitted. This is due to the rapid falloff in radiation over distance as well as the strict safety standards established by the FDA. The more interesting analysis will be any correlation between the level of radiation, power usage of the unit, and cost of the unit. We expect to find high power microwaves emit higher levels of radiation (though still at safe levels). While cheaper units may theoretically result in less safety precautions, FDA standards should prevent this at any noticeable level.

Emma Foley; Hunter Furnish; Hannah Tobias

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

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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

A Cost-Benefit Analysis of Full-Body Scanners