Monthly Archives: May 2011

Geiger Counter on an Airplane

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Geiger Counter on an Airplane

Last week I took a flight out west and back again. I wanted to take my Geiger Counter but I was worried that they might be banned. Calling the manufacture, two distributors, and a very knowledgeable person I know all, all suggested that Geiger Counters were fine to take on an airplane. I continued to worry, being me, so I checked the TSA’s website. The Website allows you to enter items to search their “banned” list. Geiger Counters, radiation detectors, and nothing of the sort would come up. I searched equivalent devices, i.e. small electronics with simple circuit boards and batteries, only to find all were acceptable to take and even use. Lastly, I contacted the TSA directly using their phone number. I spoke with an agent at length who ensured me that it would be okay if I clearly displayed the device as I was searched. It was worth the risk in the name of science!

Before anyone questions, I should explain that I took the Geiger Counter out of my carry-on and placed it in a separate plastic examination bucket by it’s self. The TSA guards glanced at it and ran it through the X-Ray machine. I only regret not having it on to see what they subjected it to. I figured that was too far. Afterward I have a polite discussion with a TSA screen-er and a passenger who complained, half humorously, about the radiation.

Unruly Passenger

While preparing for my return flight, I had already logged the data, I encountered an immediate use for my new knowledge: A gentleman was just behind me as I reapplied by belt and shoes. He complained out loud about the radiation of the body scanners. The TSA guy was about to say something in rebuttal, but I took a moment, Geiger counter in hand, to step forward and interject my two cents:

“Sir, that back scatter machine is sort of like being electronically raped, but it really only blasts you with a tiny bit of radiation for a few moments. The flight your about to get on will expose you to about a third of a milirem per hour, give or take. A four hour flight and you get 1.2 milirem of radiation. Sir, that means every 33 hours of flight you get a full power chest X-Ray. Doesn’t the doctor hide in a different room and wear a lead smock for that?”. Due to comments, I should note that the body scanner is over a thousand times less (or more) than the flight.

The TSA guy tried with careful determination not to reveal his laughter. The passenger just gave me a strange look, snatched his belt, and walked off. I looked at the TSA agent and shrugged. We were unlikely cohorts in this joke. I personally feel that fully body scanners should tip you a dollar after you’re done giving them a show. I am also annoyed by being subjected to additional radiation, but it seems to go with the flight. Perhaps one day we can abolish fully body scanners in lieu of some better approach.

The Data

I took my Geiger Counter on a Airplane last week and up to an altitude of 36,000 feet. At about 36,000 feet I stuck my hand in my bag and engaged the Geiger Counter without sound. Though they are allowed, I figured a blinking light, digital readout, and ticking noise were inadvisable show general show. I attached the data cable and plugged it into my laptop. Below are the full 17 minutes of readings I took before too many people started watching my screen. Next time, I hope to leave my laptop running with the lid down for a few hours.

17 Minutes at 36,000 feet over the Midwest USA at about early afternoon.

Radiation at 36,000 Feet

Radiation at 36,000 Feet

Minute Date Time Count Total Counts Average Count
1 5/16/11 02:46 PM 317 317 317
2 5/16/11 02:47 PM 338 655 327
3 5/16/11 02:48 PM 300 955 318
4 5/16/11 02:49 PM 318 1,273 318
5 5/16/11 02:50 PM 296 1,569 313
6 5/16/11 02:51 PM 364 1,933 322
7 5/16/11 02:52 PM 305 2,238 319
8 5/16/11 02:53 PM 315 2,553 319
9 5/16/11 02:54 PM 325 2,878 319
10 5/16/11 02:55 PM 303 3,181 318
11 5/16/11 02:56 PM 302 3,483 316
12 5/16/11 02:57 PM 350 3,833 319
13 5/16/11 02:58 PM 346 4,179 321
14 5/16/11 02:59 PM 352 4,531 323
15 5/16/11 03:00 PM 314 4,845 323
16 5/16/11 03:01 PM 366 5,211 325
17 5/16/11 03:02 PM 314 5,525 325


In Conclusion

Flying remains quite safe. I am exposed to more danger from driving to the airport than the plane. The radiation I am exposed to is quite low given short duration of the flight.

Radiation findings from Southern California

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Radiation findings from Southern California

Note: Due to the fact that I have never been to Southern California, I was unable to compare my findings to previous baseline data. Data obtained from other GM devices via was used to compare my results for normality. It must be stressed that my tests were limited in scope to a small area and a short five days of tests. Primarily, I was checking for gamma, a common result of isometric adjustment of atoms, including those who primarly produce alpha and beta radiation.


The Raw Radiation DataFor Raw Data Click Here

The Trip

 I traveled to sunny southern California this week on business but I didn’t forget my trusty Geiger Counter. As you might have noticed, I am a little sensitive about my Geiger Counter and didn’t know how the TSA would react to me bringing my toy on the airplane. Following advice I received from the TSA (I called them on the phone) I placed the Geiger Counter in the open where they could see it. This seemed to satisfy them. I found that I was kept so busy with work that I could not explore the countryside testing the plants and ground, as I had wished. Luckily, my Geiger Counter was able to run continuously during that time.

Normal Readings

 Upon entering my hotel room I quickly setup my systems and Geiger Counter to start reading. From Monday night until Friday morning I ran my Geiger Counter nearly continuously. From Monday, May 16, 2011 until Friday morning May 20, 2011 I logged a total of 3344 minutes of data. During this time I averaged 16 Counts Per Minute (herein CPM) greater than 90% of the time. 16 CPM is an ipso facto norm given the many months of data found on which show similar readings for similar elevations, in my case being approximately 400 feet above sea level.

Southern California Radiation Graph

Southern California Radiation Graph

Unexplained Spikes

 I did note many interesting, but small, spikes during my stay. Most of these “spikes” were quite innocent in appearance, never exceeding double background. I do not normally see such spikes where I am used to checking, but the very shape of the Earth’s magnetic lines of force allows some places to experience interesting attenuation of radiation. I cannot rule out periodic and local terrestrial sources, given the nature of the area in where the tests were performed, e.g. a metastable radionuclide issuing gamma from a distance, occasionally bathing my tube.

Count Date Time CPM Total Avg Lat Long Alt
53 5/18/11 11:56 PM 17 877 16 32.816835 117.051022 449ft
54 5/18/11 11:57 PM 14 891 16 32.816835 117.051022 449ft
55 5/18/11 11:58 PM 29 920 16 32.816835 117.051022 449ft
56 5/18/11 11:59 PM 17 937 16 32.816835 117.051022 449ft
Count Date Time CPM Total Avg Lat Long Alt

1,619 5/20/11 05:30 AM 15 26,115 16 32.816835 117.051022 449ft
1,620 5/20/11 05:31 AM 26 26,141 16 32.816835 117.051022 449ft
1,621 5/20/11 05:32 AM 31 26,172 16 32.816835 117.051022 449ft
1,622 5/20/11 05:33 AM 9 26,181 16 32.816835 117.051022 449ft

As you can easily see, these spikes are perhaps happenstance of the naturally random nature of radiation and not sufficient to suggest anything more than mere interest.

Air Tests

 During my time in California I did take a moment to run my testing equipment in the outside air and away from stone or other radioactive items. I tested the outside porch of my hotel room and found no prominent emitters. Given a lack of power and resources, I had to run the outside scan for a short time. The results were actually slightly lower than in the room, though a rain storm had just pasted and the area was still quite damp from pacific rain.

Southern California 5-18-11 Air Test

Southern California 5-18-11 Air Test

Lessons Learned

 My next trek will include additional equipment, such as a 3” Geiger Pancake tube for higher sensitivity, contact contamination swipe tests, rock and dirt samples, rain samples, and an extension cord.