Well this is interesting

[SeaCat]

This weekend I heard about a situation that occured in work a month ago. It interested me so I decided to look into it.

Now let me explain a bit. On my unit we often deal with radiation because we dose patients with low level Iodides for the treatment of Thyroid Cancer. (We also seed patients upon occasion which creates larger amounts of radiation.) We have our own Dosimeters. (Because I deal with radiation quite often due to my understanding of it and lack of fear of it I have my own Dosimeter.) These Dosimeters are what are called Semi-Conductor Dosimeters and are fairly accurate.

Last month one of the R.N.'s clipped her Dosimeter into the same pocket she was carrying her Cell Phone in. A bit over two hours later she checked her Dosimeter and found it was reading 6900 Milirems. Much higher than she should have been reading because she hadn't been in the radiation room. (She would have had to have been snuggled up to the patient for several hours to get that kind of reading.)

Several days later a different R.N. had the same situation arise when he clipped his Dosimeter in the same pocket as his Cell Phone.

This got me curious as it just shouldn't have been happening. A Cell Phone does emit radiation but it is not Ionising Radiation of the kind these sensors monitor. Me being me I turned on my Dosimeter and placed my Cell Phone next to it in my locker. Six hours later I checked and sure enough it was reading quite high. (18000 Milirem)

Now you have to understand that these types of readings appeared only when the Cell Phones were touching or almost touching the Dosimeters. At a distance of six inches there was no odd reading.

This doesn't make sense to me. RF Radiation is non ionising especially at the low levels produced by a cell phone.

I have sent off several letters. One to my father who knows a bit about radiation. Another to the manufactorer of the Meters and a couple more to schools and Universities. In each of the letters I explained the circumstances as well as describing and listing the ypes of meters and Cell Phones.

I shall be interested in hearing their explanations.

Cat

 

[Handley_Page]

I would also be interested to hear the results, please.
I suspect, however, that there's a very high E-field round what passes these days for the aerial on the phone. This is not unusual in an active device, but it can drive the electrons & holes in the semiconductor "round the twist".

Don't forget, a modern phone still transmits, even if it's not 'in use'.


Perhaps putting the telephone (or the dosimeter) in a different pocket might help.

hp

 

[OneLustyWench]

This weekend I heard about a situation that occured in work a month ago. It interested me so I decided to look into it.

Now let me explain a bit. On my unit we often deal with radiation because we dose patients with low level Iodides for the treatment of Thyroid Cancer. (We also seed patients upon occasion which creates larger amounts of radiation.) We have our own Dosimeters. (Because I deal with radiation quite often due to my understanding of it and lack of fear of it I have my own Dosimeter.) These Dosimeters are what are called Semi-Conductor Dosimeters and are fairly accurate.

Last month one of the R.N.'s clipped her Dosimeter into the same pocket she was carrying her Cell Phone in. A bit over two hours later she checked her Dosimeter and found it was reading 6900 Milirems. Much higher than she should have been reading because she hadn't been in the radiation room. (She would have had to have been snuggled up to the patient for several hours to get that kind of reading.)

Several days later a different R.N. had the same situation arise when he clipped his Dosimeter in the same pocket as his Cell Phone.

This got me curious as it just shouldn't have been happening. A Cell Phone does emit radiation but it is not Ionising Radiation of the kind these sensors monitor. Me being me I turned on my Dosimeter and placed my Cell Phone next to it in my locker. Six hours later I checked and sure enough it was reading quite high. (18000 Milirem)

Now you have to understand that these types of readings appeared only when the Cell Phones were touching or almost touching the Dosimeters. At a distance of six inches there was no odd reading.

This doesn't make sense to me. RF Radiation is non ionising especially at the low levels produced by a cell phone.

I have sent off several letters. One to my father who knows a bit about radiation. Another to the manufactorer of the Meters and a couple more to schools and Universities. In each of the letters I explained the circumstances as well as describing and listing the ypes of meters and Cell Phones.

I shall be interested in hearing their explanations.

Cat

Will be interesting to hear what they say. There was all that information about cancer and radiation in cell phones that was all over the news years ago.

 

[SeaCat]

I would also be interested to hear the results, please.
I suspect, however, that there's a very high E-field round what passes these days for the aerial on the phone. This is not unusual in an active device, but it can drive the electrons & holes in the semiconductor "round the twist".

Don't forget, a modern phone still transmits, even if it's not 'in use'.


Perhaps putting the telephone (or the dosimeter) in a different pocket might help.

hp

Yes the phones still do transmit even when at rest.

Notice I mentioned that when the phone and the Dosimeter are seperated by six inches the readings are normal.

I shall be interested in this.

Cat

 

[SeaCat]

Will be interesting to hear what they say. There was all that information about cancer and radiation in cell phones that was all over the news years ago.

I too am interested in the answers.

I'm wondering if the ionisation is caused by the reactions of the inorganic metal in close proximity to an RF Field as well as how Organic Materials react to an RF Field.

I too remember the fears of irradiation and the answers given at the time.

Does a Low Level RF Field cause Ionisation in Organic Materials?

Cat

 

[JackLuis]

I'll bet the issue is rectification of the RF signal by semiconductors in the Dosimeter. If the field strength of the phones RF, as sensed by the electronics in the Dosimeter exceeds the threshold value of the junction, this can simulate the sensor signal for ionising radiation, some where upstream of the rectification.

Easy fix, burn the cell phone.

 

[oggbashan]

In the early 1960s, one of the party tricks we used to demonstrate an IBM mainframe computer was to put a switched-off and battery-less transistor radio on a particular spot on the computer's casing and then run a set of punched cards containing an IBM supplied programme.

The radio's loudspeaker would play "Rule Britannia". Other programmes existed for different tunes. We modified a copy of the programme to play "Colonel Bogey".

Og

 

[JAMESBJOHNSON]

Take your dosimeter to WAL-MART and take a stroll thru the store.

 

[Handley_Page]

I too am interested in the answers.

I'm wondering if the ionisation is caused by the reactions of the inorganic metal in close proximity to an RF Field as well as how Organic Materials react to an RF Field.

I too remember the fears of irradiation and the answers given at the time.

Does a Low Level RF Field cause Ionisation in Organic Materials?

Cat

No. it causes heating.
RF energy is classed as "non-ionising" radiation. Given a large enough field (thing of a microwave oven), and a small enough sample, tissue damage can be severe.

Tissue damage from an RF field comes under the heading of how much radiation, how long exposure, and how frequent. Actually the jury's still out on the measurements.

 

[Zeb_Carter]

No. it causes heating.
RF energy is classed as "non-ionising" radiation. Given a large enough field (thing of a microwave oven), and a small enough sample, tissue damage can be severe.

Tissue damage from an RF field comes under the heading of how much radiation, how long exposure, and how frequent. Actually the jury's still out on the measurements.

I do know you don't want to walk around under the antenna array of a radio station for too long. 50,000 watts my not sound like a lot but you can feel the fillings in your teeth heat up when you walk near one.

 

[stephen55]

A good and reasonable question..........

This sounds like a job for trysail.

 

[Handley_Page]

I do know you don't want to walk around under the antenna array of a radio station for too long. 50,000 watts my not sound like a lot but you can feel the fillings in your teeth heat up when you walk near one.

That's not something I've tried, but it's a good reason to stay well clear !
We reckon 5 meters for 100w. Double the octave and square the distance.

 

[SeaCat]

OKay,

I heard back from the company that makes this particular Dosimeter. I was told to open the attached file which was the updated manual for this dosimeter and check out a special section which warns against carrying the dosimeter in the same pocket as an I-Phone. (THey did however forget to attach the file. I wrote back asking for the file.)

This tells me that this is a known problem.

As an aside the I-Phone is kind of interesting in that it emits on four different frequencies. (Quad Band) 850, 900, 1800 and 1900 MHz.

I'm wondering if it explains the cause of the problem in the file.

Cat

 

[stephen55]

This is interesting...

Even at the highest frequency, 1900 MHz, which is just barely into the microwave spectrum, the energy of that electromagnetic radiation is about 0.7 ueV. That's 0.7 millionths of an electron volt. Ionizing electromagnetic radiation starts at the higher ultraviolet range, with energies of about a few electron volts. So your dosimeter is registering electromagnetic radiation with energy levels about one to two million times less than it is supposed to. Or, it's registering something else. My bet is that it's registering something else.

You said that it is a semi-conductor (MOSFET) type dosimeter. Depending on the type of materials used to create and insulate the semi-conductors, and the actual configuration of the semi-conductors, this problem you've noticed could be due to thermal runaway caused by different rates of heating in the different materials from the microwave radiation. That your problem only occurs when the dosimeter is in close proximity to the microwave source simply means that the amount of heat created by the microwaves is barely enough to cause the problem. Moving the dosimeter a short distance from the microwave source lowers the heating below the level that caused the thermal runaway.

See...

http://en.wikipedia.org/wiki/Thermal_runaway