Radiation Basics

Some people who purchase our instruments have no background in radiation protection. So, we thought it would be helpful to include this information on our Radiation Basics support page. Much of the following information is based on features and capabilities available with most of our Radiation Alert® meters.

The presentation below will cover some of the basics for Ionizing Radiation, such as alpha, beta, gamma, and x-rays. It does not cover NON-ionizing radiation, such as microwaves, radio waves, and cellphones.

For a list of common terms and definitions, please visit the Health Physics Society’s “Radiation Terms, Definitions and Fact Sheets”.  If you can’t find what you were looking for in the following information, please check out the Radiation Answers website for additional information.


S.E. International, Inc. Radiation Basics Slide Show ©

 


 

FAQS About Radiation


The chirping sound is a notification that your battery is now.

Did you find this FAQ helpful?
0
2

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Note: Please be aware that the Ranger does not identify isotopes. It quantifies, not qualifies. However, if you know the isotope that you are surveying, you can use the pre-programmed efficiencies to calculate the activity in Becquerels and Disintegrations Per Minute. You can program your own efficiencies into the unit for your own customized application. To do so, either enter the utility menu on your detector or use the Cal Panel in the free Observer USB Software for PC

Did you find this FAQ helpful?
1
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Note: Please be aware that the Ranger does not identify isotopes. It quantifies, not qualifies. However, if you know the isotope that you are surveying, you can use the pre-programmed efficiencies to calculate the activity in Becquerels and Disintegrations Per Minute. You can program your own efficiency into the unit for your own customized application.

Radiation Alert Ranger Model Efficiencies (Counts Per Disintegration) :

Sulfur (35S): 0.0317
Strontium (90Sr/y): 0.2274
Cesium (137Cs): 0.2078
Phosphorus (32P): 0.2200
Carbon (14C): 0.0291
Iodine (131I): 0.0600
Cobalt (60Co): 0.1400
Alpha: 0.0420

Did you find this FAQ helpful?
1
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

A swipe or smear, such as cotton twill or flocked style swipes, should be used. An area of about 100 cm2 should be wiped with the swipe. The filter paper is then placed on the Wipe Test Plate and slid over the back of the Ranger. It is necessary to establish a background level first. To do this, follow the above procedure with an unused filter paper using the timed count feature of the Ranger for a period no less than 10 minutes.

The actual amount of contamination is the difference between the count rate of the wipe test and the background count rate. An area should be cleaned if the counts are greater than twice the background wipe test. Save the Wipe Test data sheet. When numerous wipes are being taken, such as when a complete lab survey is being performed, locations of wipes should be recorded on a lab diagram. If one or more wipes reveals contamination, the location of the contamination can then be determined.

Note: Be careful to place the swipe flat on the wipe test plate so that it does not come in contact with the Ranger and potentially contaminate the unit. The Wipe Test Plate, which has an electro-polished finish, can be cleaned, whereas the detector itself cannot.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

The thousandths in μSv/hr are considered statistically insignificant. Earlier versions of The SEI Inspector, such as the Original SEI Inspector, SEI Inspector Plus, and SEI Inspector EXP, show the thousandths, but newer revisions round to the hundredths.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Yes. The unit will run with a standard plug and AC adapter.

Did you find this FAQ helpful?
1
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

The latest version of the SEI Inspector USB requires that the timer be set prior to accumulating total count.

To take a timed count, follow these steps:

1. With the SEI Inspector operating, set the Mode switch to Total/Timer. The display shows 0 and Total in the upper left portion of the display.

2. Press the SET button on the end panel to set the time for your count. You will see the hourglass, and the most recent timing period used. The first time you use the timer, the setting is 00:10 (ten minutes).

3. Use the + and – buttons to set the timing period. The timed period can be for 1 to 10 minutes in one minute increments, for 10 to 110 minutes in 10-minute increments, or for 2 to 24 hours in 1 hour increments.

4. Press the SET button. The SEI Inspector starts totaling the counts it registers, and the numeric display is updated each time a count is registered. The hourglass indicator flashes during the timed period. During the counting period, if you want to see how many minutes remain, press and briefly hold the SET button. The display counts down from the time setting in hours and minutes to zero. For example, if the display shows 00:21, then 21 minutes remain.

5. At the end of the timed period, the SEI Inspector beeps 3 times and repeats the beeping 3 times. The number displayed is the total count and the hourglass will stop flashing.

6. To find the average dose rate for the timed period, divide the total by the number of minutes. The average count is in counts per minute. To convert to mR/hr for Cesium-137, divide by 3340.

7. Move the Mode switch to one of the dose/rate modes to return to normal operation. If you move the Mode switch to one of the dose/rate modes while the SEI Inspector is taking a timed count, the timed count will continue.

8. To reset the timer to take another timed count, press the SET button to set the time for another count.

9. Press the SET button a second time and the SEI Inspector will start totaling the counts it registers, and the numeric display is updated each time a count is registered.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

This has a lot to do with the alpha source itself. Starting with the source, not all particles are headed in the direction of the detector. The next challenge for the alphas is to make it off of the surface of the source. Alpha standards *must* be protected from the outside world to prevent the radioactive material from coming off. Typically, electroplated sources are used, but there are ones that exist generally using a thin sheet of Mylar and adhesive. Also, many of the alpha particles are absorbed prior to escaping the source.

Efficiency measurements are specified at a fixed distance from the source. We recommend using a source to detector distance of 1 cm for all efficiency measurements. So the attenuation of 1 cm of air must also be figured in. This can be easily achieved using the Wipe Test Plate and the Ranger.

In addition to this, the screen protects the detector face as well, so some of the incident alpha particles are stopped there.

Finally, the absorption of the mica window is considered. Once an alpha particle makes it into the active volume of the detector the intrinsic efficiency is essentially 100%.

It is possible to determine a different efficiency, using the alpha emission rate from the source (hence a 2-pi efficiency) instead of the total activity deposited. Since we have to use one number, we go with the activity-based, 4-pi efficiency, as that is most representative of how the majority of measurements are taken in the working environment. This is generally counting wipe samples and direct measurements on surfaces.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Yes. The Radiation Alert Ranger detects down to 1 microR.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Swipe assays are routinely performed in laboratories and other facilities that use or handle radioactive materials. These assays, often referred to as smear or wipe tests, are performed to comply with radioactive material license requirements, assure laboratory safety, and provide information that proper handling procedures are being followed. Typically, swipes are performed to monitor for the presence of removable surface contamination from low energy beta-emitting radionuclides. Swipe assays are also used to detect the presence of alpha contamination.

By using the Ranger wipe test plate and a swipe, you can perform a timed count and get a more accurate reading of your potential contamination.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

The Alert can be set in mR/hr or CPM. When using Utility Menu option #2 to switch units of measurements, the alert is reset to the default alert level of .1 mR/hr (1.0 mS/hr). Once the alert threshold is reached the beeper will sound until the alert is deactivated, or the radiation level drops below the set alert threshold.

1. To set the Alert, press the “SET” button on the end panel. The “ALERT” icon (radiation symbol) and the “SET” icon are displayed.

2. Use the “+” and “-” buttons to adjust the display to the desired level.

3. Press the “Set” button once to retain the setting in memory. Then press it again to turn the alert mode on. The “ALERT” icon is now displayed to indicate the instrument is operating in the Alert mode.

4. To use the previous alert setting, press the set button twice. Now the alert mode is on.

5. To deactivate the Alert

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Some of our Radiation Alert® models have specifications that state the lowest reading is .01 microSv/hr. If you have a reading lower than .01 microSv/hr, it may be an accurate reading, however, we cannot guarantee the accuracy of a reading that low.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Due to the short pulse width of some x-ray pulse generators, Geiger Mueller counters cannot detect X-rays emitted. The Ranger, for example, may start to miss counts when a pulse width of the X-ray goes below 40 microseconds. Typically, it is recommended to use ionization chambers for this application.

Did you find this FAQ helpful?
1
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

The SEI Inspector detects x-rays and gammas down to 10 KeV through the end window and down to 40 KeV through the sidewall.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Do to the random nature of radiation emissions, there can be instances where a few counts are recorded at the same time. The light would only flash once and a single “click” sound would occur, but the reading would display a few simultaneous counts.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

The efficiency of a detector, expressed in percentages, is the probability that an emitted gamma ray will interact with the detector and produce a count, representing the probability that a gamma ray of a specified energy passing through the detector will interact and be detected.

The objective will be to define efficiencies for specific isotopes. Additionally, to quantify the data generated when using one of the Radiation Alert Wipe Test/Planchet systems. Efficiencies can be generated for a myriad of isotopes through a simple procedure. In the following example the efficiency of the Radiation Alert Ranger WTP to an alpha/beta source deposited onto a planchet will be determined. A similar procedure can be used to determine efficiencies for wipe tests.

This procedure assumes that an alpha/beta source of known activity has been prepared and applied to a planchet. In addition, the average normal background (CPM) has already been determined with the Wipe Test Plate in position.

The first step is to take a ten minute count with the planchet (source) sitting on the Wipe Test Plate (shorter count times may be used). Using the Wipe Test Plate assures reproducible geometry and that results will be comparable. Next, convert the gross counts obtained for the ten minute interval into counts per minute (CPMnet) above normal background using the following equation:


Equation 1


After  is obtained a value for the detector efficiency, E, can be determined.The equation for E is as follows:

Equation2


It should be noted that both the count Rate and the activity must share the same units of time (i.e. CPM and DPM or CPS and Bq). The efficiency will always be less than 1 and have units of counts per disintegrations (c/d). The efficiency may also be expressed as a percent.

Finally, to convert a reading taken from a planchet using the Inspector + WTP into activity use Equation 4 or 5:

Equation 3


Or,

Equation 4


To determine activity when the efficiency is supplied in a percent, use either of the above equations and multiply the result by 100.

Finally, to convert DPM or DPS(Bq) into Curies(Ci) use Equation 6 or 7 :

Equation 5


Or,

Equation 6


Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

The assembly of our scintillation probes is hermetic, so there will be no degradation over time due to the crystal, unless the entrance window is broken. There could be a change in calibration over a long period of time due to a slow burn in of the PMT. The odds of any failure in the long term (10 years or more) would be due to dropping the probe or some other unfortunate destructive event.

However, you will need to calibrate your detector with whichever device you are connecting it to achieve optimal accuracy.

Did you find this FAQ helpful?
0
0

Comment on this FAQ

Your email address will not be published. Required fields are marked *

Converting CPM to mR/hr


Sensitivity is expressed in cpm per mR/h. Mathematically the cpm units cancel leaving mR/h.

For example, if you have collected 200CPM with the Radiation Alert Ranger, which has a typical gamma sensitivity of 3500 cpm per mR/hr, you would divide the 200 cpm by the 3500cpm per mR/hr sensitivity. The cpm cancels out and you are left with 200/3500 mR/hr = 0.057 mR/hr

Did you find this FAQ helpful?
0
0
  • Dear Sir,

    What would be the X-Ray sensitivity factor in cpm/mR/hr? Is it similar to the gamma sensitivity of 3,500 cpm per mR/hr? Thanks.

    Sincerely,
    Cliff

    • Hi Cliff,

      X-rays and Gamma are treated the same by the detector. The difference comes in with the pulse width of the X-ray itself. If the pulse width is smaller than the dead time of the tube (15 microseconds for the SentryEC), then you might miss some of the counts. Otherwise, you can use the Gamma Energy Response graph on the SentryEC page to find your answer for specific energies.

      https://seintl.com/sentry-ec

  • Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    The Energy Response Graph shown in the operation manual gauges how the instrument will respond to various energies. GM detectors cannot distinguish different types of energies, but we can gauge how the detector responds to them.

    Monitor 200 & Monitor 4 Energy Response To Gamma Cs137
    Monitor 200 & Monitor 4 Energy Response To Gamma Cs137

    For example, on the graph shown above, the M4 Sidewall response starts at 30 keV with a relative count rate of 3. An isotope giving off radiation at 30 keV might cause the GM tube to over respond by 3X. This means the detector may be reading that there is three times the exposure present. At its highest peak, the meter will over respond showing 7 times the rate at 60 keV. The Monitor 4 will start to have a relative response of 1 at about 500 keV.

     

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    You can find an online Interactive Table of the Elements from TouchSpin.com by clicking here

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Typically, most large GM based detectors will detect 2 feet into any load of scrap metal. To perform a survey, scan with the meter window 1cm from the source and move the meter about 2 inches per second over the material you are surveying.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Click here to contact the Conference of Radiation Control Program Directors. Inc. (CRCPD) for a list of professionals in your area.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    None of the instruments listed in this website detect neutron, microwave, RF (radio frequency), laser, infrared, or ultraviolet radiation. All of the instruments are most accurate for Cesium 137 and isotopes of similar energies. Some isotopes detected relatively well are Cobalt 60, Technetium 99M, Phosphorous 32, Strontium 90, and many forms of Radium, Plutonium, Uranium, and Thorium.

    Some forms of radiation are very difficult or impossible for a Geiger tube to detect. Tritium is a byproduct of a nuclear reactor and is used in research. The beta emissions from Tritium are so weak that there are very few instruments that are capable of detecting it. More sophisticated equipment is needed for the measurement of environmental samples, such as radioactivity in milk, produce, soil, etc., unless you are looking for gross contamination.

    The radiation from some isotopes can cause a Geiger tube to overexcite and indicate a higher level of radiation than is actually present. Americium 241 is an example of this phenomenon. Americium 241 is used in some smoke detectors and many different types of industrial density and flow meters.

    Unless you know exactly what you are measuring and understand the limitations of detection instruments, it is possible to draw misleading conclusions from your readings. We design our instruments to detect the broadest range of ionizing radiation possible and still be affordable. The full spectrum of ionizing radiation cannot be measured by one single instrument.

    Everyone agrees that radioactive materials can be dangerous.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Geiger counters can detect the four main types of ionizing radiation: alpha, beta, gamma, and x-rays. Some detect only gamma and x-rays. Our instruments are calibrated to Cesium 137, but also serve as excellent indicators for many other sources of ionizing radiation. Gamma and x-rays are measured in milli-Roentgens per hour (mR/hr), micro-Sieverts (µSv/hr), or milli-Sieverts (mSv/hr). Alpha and beta are measured in counts per minute (CPM) or counts per second (CPS).

    The window of the GM tube is very thin mica. This mica window is protected by a screen. Some levels of alpha, low energy beta, gamma, and x-rays that cannot penetrate the plastic case or the side of the tube can be sensed through the window.

    Although some beta and most gamma radiation can go through protective gear, try to avoid skin contamination and ingestion. When you leave a radioactive area, remove any protective outerwear and dispose of it properly. If you think you have been contaminated, as an additional precaution, shower and consult a physician.

    To determine whether the radiation detected is alpha, beta, or gamma, hold the instrument toward the source.

    Alpha: If there is no indication through the back of the case (the side of the tube), position the window close to but not touching the source. If there is an indication, it is alpha, beta, or low energy gamma. If a sheet of paper placed between the window and the source stops the indication, it is most likely alpha. To avoid particles falling into the instrument, do not hold the source above the window.

    Beta: Place a piece of aluminum about 1/8 inch (3 mm) thick between the instrument and the source. If the indication stops, decreases, or changes, it is most likely beta radiation. Most common isotopes emit both beta and gamma radiation. This is why the indication would decrease or change but not stop.

    The non-occupational dose limits set by the government is 100 mR per year above background per year. It is up to the individual to decide what a safe radiation level is. It will be different depending on the individual and their knowledge of radiation and its affects. Radiation levels will vary according location and circumstances. As an example; if your background level is 25 CPM (counts per minute) where you live, when you fly in an airplane at 30,000 feet your rate meter may measure 200 CPM (.2 mR) for 2 to 5 hours. That is 8 times your normal background radiation on the ground, but it is only for a limited amount of time.

    When measuring radiation in an emergency response situation, it is good to have something to compare your readings to. Taking a background radiation level reading in your area before a radiation event will help you determine if you have an elevated level of radiation and whether or not to stay in that location. Background radiation is naturally occurring radiation that is always present. It includes; high energy gamma rays from the sun and outer space and alpha, beta, gamma radiation emitted from elements in the earth. Using a rate meter, you can determine your normal background radiation levels.

    For a good emergency response kit for radiation we recommend a general purpose Geiger counter (like the Monitor 4), a carbon fiber dosimeter (such as the PEN200) and a Charger to reset the dosimeter. There are electronic dosimeters, however, if you were in the blast zone of an atomic bomb the pulse of the bomb would make most electronic equipment inoperable. The carbon style dosimeters will still operate.

    Gamma: If there is an indication of radioactivity, it is most likely gamma or high energy beta. Low energy gamma and x-rays (10-40 keV) cannot penetrate the side of the GM tube, but may be detected through the window.

    If you perform the alpha/beta test above and there is no change or only a very slight change in the indication, the source is emitting primarily gamma radiation.

     

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    How to Detect Background Radiation

    To see what the background radiation is in your area, simply turn the instrument on and, after the 30 second start up beep, the general background radiation will be displayed.

     

    How To Survey a Surface

    When surveying a surface, such as a counter top, you will need to hold The Ranger about 1-2 centimeters from the surface while moving the unit horizontally across the survey area at a rate of 2 inches per second.

     

    How to Perform a General Survey

    A general survey would be used to find a potential source. For example, if you are looking for a potential source in a pile of scrap, The Ranger will typically detect about 2 feet into a pile. It is easier to find a source when The Ranger is set to Fast Response mode. However, even if The Ranger is in Auto-Averaging mode, the audio clicks that indicate a count should be a sufficient indicator if a potential source is present. To find the source, slowly move The Ranger in the direction of the higher readings or clicks until the potential source is found.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    The dead time has to do with detector size, anode resistor valve, and the distance of the anode resistor from the detector.

    In general the smaller the detector the shorter the dead time. The lower the resistor value the shorter the dead time. The closer the anode resistor is to the anode the shorter the dead time.

    Energy compensation does not contribute to the dead time of a detector.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    kV is actually the kilo Voltage at which an x-ray tube is operated.KeV is the is the energy that an electron gains when it travels through a potential of one thousand volt.When an x-ray tube is operated at 50kV the electrons from the cathode are accelerated towards the anode and the electrons, on hitting the anode, produce the x-rays. The x-rays thus produced will have a a spectrum of energies from a few keV to a maximum of 50keV. The average energy of the x-rays will be approximately one-third of the maximum energy 50 keV.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    The 10 keV mentioned in some of our specifications is specific to gamma/x rays. For beta particles, it is a bit different. For example, the detector used in The Ranger and Abacus units has an “Areal density” listed as 1.5 to 2.0 mg/cm^2. Looking this up on a beta particle range/energy curve, this thickness will stop all betas up to about 35 keV. Therefore the ABSOLUTE minimum beta energy that can be detected is about 35 keV, not taking into account any other physical factors (distance, self-absorption, the grill over the detector, etc.).

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    The six samples in our NORM (Naturally Occurring Radioactive Material) Student Kit contain tiny quantities of radioactive material obtainable commercially by anyone who wants to purchase them. No radioactive material license is required to possess or transport them. The quantities are individually and collectively well below the IATA Activity Limit for an Exempt Consignment (from IATA Dangerous Goods Regulations Table 10.3.A) and U.S. Department of Transportation regulations 49 CFR 173.436). No shipping label of any kind is required, no Declaration for Dangerous Goods, and no packaging requirements are specified.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    United States:

    1) Right Click the Observer USB icon in the system tray.
    2) Click Exit Observer USB
    3) Restart your computer
    4) Once the computer has rebooted, plug your unit back into the computer.
    5) If the software window still does not launch, power cycle the M200 while it is plugged into the computer.
    International:

    Windows 7:

    1) Click Start > Control Panel on your PC
    2) Click on Clock, Language, and Region
    3) Under Region and Language, click Change the date, time, or number format
    4) In the Region and language window, select English (United States) from the Format drop down menu.
    5) Click Additional Settings to open the Customize Format window.
    6) Make sure that the Decimal Separator is a period and the List Separator is a comma
    7) Click Apply and close the Customize Format Window.
    8) Click Apply and close the Region and language window.
    9) Restart your computer.
    10) Restart your unit and plug it back in via the provided USB cable.

    Restart your unit and plug it back in via the provided USB cable. If you are still experiencing issues retrieving your data, please try the steps under United States (above). If that does not resolve the issue, please contact us.

    Windows 10:

    1) Click Start > Control Panel on your PC
    2) Click on Time and Language
    3) Click Additional date, time, & regional settings to open the Clock, Language, and Region window.
    4) Under Region, click Change date, time or number formats to open the Region window
    5) Select English (United States) from the Format drop down menu.
    6) Click Additional Settings to open the Customize Format window.
    7) Make sure that the Decimal Separator is a period and the List Separator is a comma
    8) Click Apply and close the Customize Format Window
    9) Click Apply and close the Region and language window.
    10) Restart your computer

    Restart your unit and plug it back in via the provided USB cable. If you are still experiencing issues retrieving your data, please try the steps under United States (above). If that does not resolve the issue, please contact us.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Each model has 5452 data points available in the on-board memory.

    This means, for example, that you can record 3.79 days worth of data if you have chosen to record data in 1 minute intervals. To break it down, 1 save per minute is 60 saves per hour. 60 saves over a 24 hour period is 1440 saves. 5452 divided by 1440 is 3.7 days.

    If you would like to record readings for a longer period of time, then change the unit to record less frequently. For example, changing the data logging frequency to every 10 minutes will give you 37 days worth of readings. 1 save per every 10 minutes is 6 saves per hour. 6*24=144 saves. 5452 divided by 144=37 days.

    The on-board memory records the time and date with each reading. In addition, the data reflects the total counts collected during the chosen time interval, the highest and lowest rate in that time frame and the second in which each happened during the selected time internal. This means that if you selected to record data every 5 minutes, you will see the data during that 5 minute interval.

    Here’s an example:

    Date Time Total (Counts) Interval (Minutes) Highest (cpm) Hi Time (seconds) Lowest (cpm) Lo Time (seconds)
    1/2/2014 17:21 163 5 48 103 18 10

    Download Observer USB Sample Data

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Not currently. Neutrons are too high of an energy and too fast for standard GM tubes to detect. Neutrons need to be slowed down in order to detect them using a (BF3) boron trifluoride (uses a neutron to alpha particle conversion to get a measurement)or a High Pressure Helium 3 probe (uses a neutron to positron conversion to get a measurement).

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    No. Our instruments detect ionizing radiation. Microwaves are non-ionizing radiation.

    DO NOT PLACE OUR INSTRUMENTS IN A MICROWAVE AS IT MAY DAMAGE THE INSTRUMENT OR THE MICROWAVE OVEN.
    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Technically, you can use the kusnetz method or the tsivoglou method with our instruments for radon detection, however, these tests should be preformed by a trained professional. There are much more practical commercially available tests for detecting radon. These are available at many home improvement stores, or you can contact your local RSO or Radiological Health Department for more information.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Roentgen

    represented by “R”, is the unit of measurement that indicates the charge produced in air by x or gamma rays, whereas SI Units are n terms of coulombs per kilogram of air (C kg-1).

    1R = 2.58 X 10-4 C kg-1

    Radiation Absorbed Dose and KERMA (Kinetic Energy Released in Material)

    100 rad = 1 gray (Gy) 0.01 Gy = 1 rad

    Radiation Dose Equivalent

    100 rem = 1 sievert (Sv) 0.01 Sv = 1 rem
    1 µSv = 0.1 mrem

    Activity

    1 disintigration per second = 1 becquerel (Bq)
    2.7 X 10-11 curie (Ci) = 1 Bq
    1 µCi = 37 kBq
    1 mCi = 37 MBq
    1 Bq = 27 pCi
    370 MBq = 10 mCi

    SI Unit Prefixes

    10-3 milli m
    10-6 micro µ
    10-9 nano n
    10-12 pico p
    103 kilo k
    106 mega M
    109 giga G
    1012 tera T


     

    Common Units

    0.001 mSv

     = 1 µSv
    = 0.1 mR
    = 100 µR

    1 mR

    = 1000 µR
    = 0.01 mSv
    = 10 µSv

    100 mR

    = 1 mSv
    = 1000 µSv
    = 100,000 µR

    Online Calculators : Unit Converter | Convert Me

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Since the event of September 11, we have had an increased amount of calls from individuals wanting to be informed if a radiation event takes place. Radiation is a scary topic for most individuals, but some basic knowledge will help in determining what action to take when exposed to radiation in an emergency response situation.

    The types of radiation encountered during such an event are alpha, beta, and gamma. Alpha and beta are particles and gamma is a ray/photon. A piece of paper can stop alpha and a few millimeters of aluminum foil can stop most betas. We say most beta energies because there are high energy betas that are more penatrable. Most people consider alpha and beta not to be of a concern; however, these particles can be ingested or inhaled and cause damage to the body. There are high and low levels of gamma, but the primary concern with gamma radiation is the amount of time you are exposed to it.

    There are two types of monitoring devices that are applicable in an emergency response to radiation. One is a rate meter/general purpose Geiger counter. This type of instrument shows the rate that the radiation is being received. The other is a dosimeter. A dosimeter shows the amount/dose being received.

    When measuring radiation in an emergency response situation, it is good to have something to compare your readings to. Taking a background radiations level in your area before a radiation event, will help you determine if you have a radiation elevation and whether or not to stay in that location. Background radiation is naturally occurring radiation that is always present. It includes; high energy gamma rays from the sun and outer space and alpha, beta, gamma radiation emitted from elements in the earth. Using a rate meter, you can determine what your normal background is.

    It is up to the individual to decide what a safe radiation level is because it differs depending on the individual and their knowledge of radiation and its affects. As an example; say your background level is 25 CPM (counts per minute) where you live. When you fly in an air plane at 30,000 feet your rate meter is getting 200 CPM for anywhere between 2 to 5 hours. That is 8 times what your normal background is on the ground, but it is for a limited amount of time. There are non-occupational dose limits set by the government which is 100 mR per year above background per year.

    What we suggest for a good emergency response kit for radiation is a general purpose Geiger counter like the Monitor 4, a carbon fiber dosimeter such as the PEN200 and a Charger to reset the dosimeter. There are electronic dosimeters, however, if you are in the blast zone of a nuclear bomb the pulse of the bombs render most electronic inoperable but the carbon style dosimeters will still operate.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Generally, depending on the shield material, our instruments will detect radiation up to 18 -24 inches through shielding.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    We recommend yearly calibrations, although our instruments hold a stable calibration and rarely need adjusting.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Smoke Detectors: Some smoke detectors contain a sealed radioactive isotope as part of the smoke sensing mechanism. There is no danger to the individual if the container in sealed. They are labeled.

    Camping Lantern Mantles: In recent years this has changed but some lantern mantles are made with radioactive Thorium. Be especially careful not to inhale or ingest the fine ash that is left when they are burned out.

    Clocks, Watches, and Timers: Many old timepieces have dials painted with radium to make them glow in the dark. Tritium is now commonly used to obtain the same effect. Tritium is also radioactive but emits low energy radiation which cannot penetrate the lens of the timepiece.

    Jewelry: Some gold used to encapsulate radium and radon for medical purposes was improperly reprocessed and entered the market as radioactive rings and other types of gold jewelry. Some imported cloisonné being glazed with uranium oxide exceeds U.S. limits. Some gems are irradiated by an electron beam or in an accelerator to enhance their color. Irradiated gems typically are held until there is no residual activity remaining.

    Rock Collections: Many natural formations contain radioactive materials. Hobbyists who collect such things should vent the rooms in which these items are stored and be careful to avoid inhaling the fine dust particles from these samples.

    Pottery: Some types of pottery are glazed with uranium oxide, such as Fiesta ware. To the best of our knowledge, this process has been discontinued, although some of these pieces are still in circulation.

    Did you find this FAQ helpful?
    1
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Alpha

    Positively charged particles emitted from the nucleus of an atom. Alpha particles are relatively large, and very heavy. Due to this strong (+) charge and large mass, an alpha particle cannot penetrate far into any material. A sheet of paper or an inch of air can usually stop most alpha particles.

    Background Radiation

    Naturally occurring radiation is always present, it includes high energy gamma rays from the sun and outer space and alpha, beta, and gamma radiation emitted from elements in the earth.

    Beta Particles

    Negatively charged particles emitted from an atom. Beta particles have a mass and charge equal to that of an electron. They are very light particles (about 2,000 times less mass than a proton) and have a charge of -1. Because of their light mass and single charge, beta particles can penetrate more deeply than alpha particles. A few millimeters of aluminum will stop most beta particles.

    Bq (Becquerels)

    A quantity of radioactivity in which one atom is transformed per second. 1 dps (one disintegration per second).

    CPM (counts per minute)

    The unit of measurement usually used to measure alpha and beta radiation.

    Gamma Rays

    Short wavelength electromagnetic radiation higher in frequency and energy than visible and ultraviolet light. Gamma rays are emitted from the nucleus of an atom. These high energy photons are much more penetrating than alpha and beta particles.

    Ion

    An atomic particle, atom, or molecule that has acquired an electrical charge, either positive or negative, by gaining or losing electrons.

    Ionization

    The process by which neutral atoms of molecules are divided into pairs of oppositely charged particles known as ions.

    Ionizing Radiation

    Radiation capable of producing ionization by breaking up atoms or molecules into charged particles called ions.

    Radiation

    The emission and propagation of energy through space or through matter in the form of particles or waves.

    Roentgen (rent-gen)

    A basic unit of measurement of the ionization produced in air by gamma or x-rays. One Roentgen (R) is exposure to gamma or x-rays that will produce one electrostatic unit of charge in one cubic centimeter of dry air. One thousand milliroentgen (1,000 mR)= 1R.

    Radionuclide

    The naturally occurring or artificially produced radioactive form of an element.

    Sievert

    A unit of dose equivalent. 1 Sv= 100 roentgens, 10 µSv/hr = 1 milliroentgen/hr. (µSv micro-Sievert, micro is one millionth, milli is one thousandth.)

    X-Rays

    Electromagnetic radiation (photons) of higher frequency and energy than visible and ultraviolet light, usually produced by bombarding a metallic target with high speed electrons in a vacuum. X-rays are photons emitted by interactions involving orbital electrons rather than atomic nuclei. X-rays and gamma rays have the same basic characteristics. The only difference between them is their source of origin.

    Other Sources

    SciTechEng

    Major Uses of Radioisotopes in the United States – Ohio University Dept of Laboratory and Radiatio Safety

     

    Americum-241 Used in many smoke detectors for homes and businesses to measure levels of toxic lead in dried paint samples, to ensure uniform thickness in rolling processes like steel and paper production, and to help determine where oil wells should be drilled.

    Cadmium-109 Used to analyze metal alloys for checking stock and scrap sorting. Calcium-47 Important aid to biomedical researchers studying the cellular functions of bone formation in mammals.

    Californium-252 Used to inspect airline luggage for hidden explosives, to gauge moisture content of soil in the road construction and building industries, and to measure the moisture of materials stored in soils.

    Carbon-14 Major research tool. Helps in research to ensure that potential drugs are metabolized without forming harmful by-products. Used in biological research, agriculture, pollution control, and archeology.

    Cesium-137 Used to treat cancerous tumors, to measure correct patient dosages of radioactive pharmaceuticals, to measure and control the liquid flow in oil pipelines, to tell researchers whether oil wells are plugged by sand, and to ensure the right fill level for packages of food, drugs, and other products. (The products in these packages do not become radioactive)

    Chromium-51 Used in research in red blood cell survival studies.

    Cobalt-57 Used as a tracer to diagnose pernicious anemia.

    Cobalt-60 Used to sterilize surgical instruments, and to improve the safety and reliability of industrial fuel oil burners. Used in cancer treatment, food irradiation, gauges, and radiography.

    Copper-67 When injected with monoclonal antibodies into a cancer patient, helps the antibodies bind to and destroy the tumor.

    Curium-244 Used in mining to analyze material excavated from pits and slurries from drilling operations.

    Gallium-67 Used in medical diagnosis.

    Iodine-123 Widely used to diagnose thyroid disorders and other metabolic disorders including brain function.

    Iodine-125 Major diagnostic tool used in clinical tests and to diagnose thyroid disorders. Also used in biomedical research.

    Iodine-129 Used to check some radioactivity counters in in-vitro diagnostic testing laboratories.

    Iodine-131 Used to treat thyroid disorders.

    Iridium-192 Used to test the integrity of pipeline welds, boilers and aircraft parts and in brachytherapy/tumor irradiation.

    Iron-55 Used to analyze electroplating solutions and to detect the presence of sulphur in the air. Used in metabolism research.

    Krypton-85 Used in indicator lights in appliances such as clothes washers and dryers, stereos, and coffee makers; used to gauge the thickness of thin plastics and sheet metal, rubber, textiles and paper, and to measure dust and pollutant levels.

    Nickel-63 Used to detect explosives, and in voltage regulators and current surge protectors in electronic devices, and in electron capture detectors for gas chromatographs.

    Phosphorus-32 Used in molecular biology and genetics research.

    Phosphorus-33 Used in molecular biology and genetics research.

    Plutonium-238 Has powered more than 20 NASA spacecraft since 1972.

    Polonium-210 Reduces the static charge in production of photographic film and other matierals.

    Promethium-147 Used in electric blanket thermostats, and to gauge thickness of thin plastics, thin sheet metal, rubber, textile and paper.

    Radium-226 Makes lighting rods more effective.

    Selenium-75 Used in protein studies in life science research.

    Sodium-24 Used to locate leaks in industrial pipelines, and in oil well studies.

    Strontium-85 Used to study bone formation and metabolism.

    Sulphur-35 Used in survey meters by schools, the military and emergency management authorities. Also used in cigarette manufacturing sensors and medical treatment.

    Technetium-99m Used in genetics and molecular biology research. The most widely used radioactive pharmaceutical for diagnostic studies in nuclear medicine. Different chemical forms are used for brain, bone, liver, spleen, and kidney imaging and also for blood flow studies.

    Thallium-201 Used in nuclear medicine from nuclear cardiology and tumor detection.

    Thallium-204 Measures the dust and pollutant levels on filter paper, and gauges the thickness of plastics, sheet metal, rubber, textiles, and paper. Thoriated Tungsten Used in electric arc welding rods in construction, aircraft, petrochemical and food processing equipment industries. They produce easier starting, greater arc stability and less metal contamination.

    Thorium-229 Helps fluorescent lights last longer.

    Throium-230 Provides coloring and fluorescence in colored glazes and glassware. Tritium Major tool for biomedical research. Used in life science and drug metabolism studies to ensure the safety of potential new drugs, for self-luminous aircraft and commercial exit signs, for luminous dials, gauges and wrist watches, to produce luminous paint, and for geological prospecting and hydrology.

    Uranium-234 Used in dental fixtures like crowns and dentures to provide a natural color and brightness.

    Uranium-235 Fuel for nuclear power plants and naval nuclear propulsion systems, and used to produce fluorescent glassware, a variety of colored glazes, and wall tiles.

    Xenon-133 Used in nuclear medicine for lung ventilation and blood flow studies.

    Did you find this FAQ helpful?
    1
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    “MARSSIM” is the “Multi-Agency Radiological Survey and Site Investigation Manual,” a document widely used in designing and carrying out radiological surveys in support of license termination. With the MARSSIM Method the confidence level is locked in at 95% and 3 is used for the “k²” value. This affects, then, only calculations for Ld, MDA, and LLD. This method was proposed by Dr. Alan Brodsky and was adopted in the MARSSIM manual. In truth, whether the MARSSIM method or the “traditional” method (proposed by Lloyd Currie) is used, very little difference is seen in the end result. The MARSSIM/Brodsky method should be more accurate when low background count rates are present. To match the MARSSIM methodology and Brodsky recommendations exactly, the sample counting time and background counting time should be identical, although MARSSIM does state that other methods exist that adjust for these differences.

    What types of radiation do your instruments detect?

    Our instruments detect ionizing radiation. Types of ionizing radiation are Alpha (a), Beta(ß), Gamma(y), X-ray (x). Examples of NON-ionizing radiation are microwaves and radio waves.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    A Geiger counter senses ionizing radiation by means of a GM (Geiger Mueller) tube. Some tubes have a thin mica window. When a ray or particle of ionizing radiation enters or passes through the tube, it is sensed electronically and displayed on the meter or LCD and by a red count light. When the switch is in the AUDIO position, the instrument will also beep with each radiation event.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Geiger counters can detect the four main types of ionizing radiation: alpha, beta, gamma,and x-rays. Some detect only gamma and x-rays. Our instruments are calibrated to Cesium 137, but also serve as excellent indicators for many other sources of ionizing radiation. Gamma and x-rays are measured in Milli-Roentgens per hour (mR/hr), Micro-Sieverts (µSv/hr), or Milli-Sieverts (mSv/hr). Alpha and beta are measured in counts per minute (CPM) or counts per second (CPS).

    The window of the GM tube is very thin mica. This mica window is protected by a screen. Some levels of alpha, low energy beta, gamma, and x-rays that cannot penetrate the plastic case or the side of the tube can be sensed through the window.

    Try not to touch the instrument to any suspected radioactive substance.

    Although some beta and most gamma radiation can go through protective gear, try to avoid skin contamination and ingestion. When you leave a radioactive area, remove any protective outerwear and dispose of it properly. If you think you have been contaminated, as an additional precaution, shower and consult a physician.

    To determine whether the radiation detected is alpha, beta, or gamma, hold the instrument toward the source.

    Alpha: If there is no indication through the back of the case (the side of the tube), position the window close to but not touching the source. If there is an indication, it is alpha, beta, or low energy gamma. If a sheet of paper placed between the window and the source stops the indication, it is most likely alpha. To avoid particles falling into the instrument, do not hold the source above the window.

    Beta: Place a piece of aluminum about 1/8 inch (3 mm) thick between the instrument and the source. If the indication stops, decreases, or changes, it is most likely beta radiation. Most common isotopes emit both beta and gamma radiation. This is why the indication would decrease or change but not stop.

    The non-occupational dose limits set by the government is 100 mR per year above background per year.

    It is up to the individual to decide what a safe radiation level is. It will be different depending on the individual and their knowledge of radiation and its affects. Radiation levels will vary according location and circumstances. As an example; if your background level is 25 CPM (counts per minute) where you live, when you fly in an airplane at 30,000 feet your rate meter may measure 200 CPM (.2 mR) for 2 to 5 hours. That is 8 times your normal background radiation on the ground, but it is only for a limited amount of time.

    When measuring radiation in an emergency response situation, it is good to have something to compare your readings to. Taking a background radiation level reading in your area before a radiation event will help you determine if you have an elevated level of radiation and whether or not to stay in that location. Background radiation is naturally occurring radiation that is always present. It includes; high energy gamma rays from the sun and outer space and alpha, beta, gamma radiation emitted from elements in the earth. Using a rate meter, you can determine your normal background radiation levels.

    For a good emergency response kit for radiation we recommend a general purpose Geiger counter (like the Monitor 4), a carbon fiber dosimeter (such as the PEN200) and a Charger to reset the dosimeter. There are electronic dosimeters, however, if you were in the blast zone of an atomic bomb the pulse of the bomb would make most electronic equipment inoperable. The carbon style dosimeters will still operate.

    Gamma: If there is an indication of radioactivity, it is most likely gamma or high energy beta. Low energy gamma and x-rays (10-40 keV) cannot penetrate the side of the GM tube, but may be detected through the window.

    If you perform the alpha/beta test above and there is no change or only a very slight change in the indication, the source is emitting primarily gamma radiation.

    Did you find this FAQ helpful?
    0
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    None of the instruments listed in this website detect neutron, and don’t detect non-ionizing radiation, like microwave, RF (radio frequency), laser, infrared, or ultraviolet radiation. All of the instruments are most accurate for Cesium 137 and isotopes of similar energies. Some isotopes detected relatively well are Cobalt 60, Technetium 99M, Phosphorus 32, Strontium 90, and many forms of Radium, Plutonium, Uranium, and Thorium.

    Some forms of radiation are very difficult or impossible for a Geiger tube to detect. Tritium is a byproduct of a nuclear reactor and is used in research. The beta emissions from Tritium are so weak that there are very few instruments that are capable of detecting it. More sophisticated equipment is needed for the measurement of environmental samples, such as radioactivity in milk, produce, soil, etc., unless you are looking for gross contamination.

    The radiation from some isotopes can cause a Geiger tube to overexcite and indicate a higher level of radiation than is actually present. Americium 241 is an example of this phenomenon. Americium 241 is used in some smoke detectors and many different types of industrial density and flow meters.

    Unless you know exactly what you are measuring and understand the limitations of detection instruments, it is possible to draw misleading conclusions from your readings. We design our instruments to detect the broadest range of ionizing radiation possible and still be affordable. The full spectrum of ionizing radiation cannot be measured by one single instrument. Everyone agrees that radioactive materials can be dangerous. We encourage you to seek out other sources of information.

    Did you find this FAQ helpful?
    1
    0

    Comment on this FAQ

    Your email address will not be published. Required fields are marked *

    Load More