Radiation is a tricky thing to deal with. In small amounts, it is potentially harmless. However, large concentrations of radiation can cause immense risks to human, plant and animal life. Risks include the loss of hair, appetite, nausea, degenerative birth defects, internal bleeding, cataracts, cancerous cells, and ultimately death. Handheld Radiation Detectors can prevent catastrophic consequences in areas with a high risk of radiation leaks, saving thousands of lives. An understanding of these devices however is the necessary first step to the process.
Introduction to the basics of Handheld Radiation Detectors
In order to detect the amount of radiation energy in a particular area, a portable device like the hand-held radiation detector is often the weapon of choice. It can sufficiently detect, to measure and to identify the nature of radiation. Used extensively in the scrap industry, it can enable collection of potentially radioactive materials and eliminate it safely. They are also used extensively in environments that generate or utilize nuclear energy, such as nuclear thermal plants and laboratories. These detectors offer a good amount of sensitivity, although a little technical training is required for using them well. There are several companies like Ecotest which provide a wide range of radiation monitoring meters.
Functional Aspects of Handheld Radiation Detectors
The three main functions of radiation detectors is as follows: detecting the radiation, measuring the amount of radiation, and identifying the type of radiation. It is generally acknowledged that the ability to detect radiation is the most important. Many detection instruments require operators to keep a watch on the digital display, but the most efficient ones should ideally have meters and audible signals for when the radiation threshold has been reached. When it comes to measuring radiation amounts, display scales vary between microR/hr. Generally, REM, CPM and CPS systems don’t really give a clear idea of the extent of radiation. Typical meters tend to be extra-sensitive, over-estimating the amounts for lower gamma charges, but true dose meters generally have lower sensitivities. Identification is an important factor because this determines how long the device will take to detect presence of radiation, including the type of isotope involved in the leak.
The Pros and Cons of using Portable Detectors
When using a portable detector, you have to be aware of both its strengths and its weaknesses. For instance, one of the positives of using a portable detector is that it can be placed directly next to the scrap of material. This versatility of the detector gives you better chances of detection, even for remote areas otherwise inaccessible with machines. Usually, the cost of portable detectors is also quite inexpensive in comparison to other kinds of detection mechanisms. The only defect with these detectors is that they require labor and expertise: you need a trained operator, especially since the machine’s sensitivity is very much dependent on its use. Otherwise, these detectors are some of the best possible radiation detectors around.
Radiation Detectors Available in the Market
Successful detection depends very much on the strengths and weaknesses of a particular radiation detector. That is because some machines are made to order for sensitivity, others for ruggedness, while still others for spectral resolution. Other areas where different radiation detectors perform differently are measurement linearity and types of radiation that can be detected. Some types include:
- Geiger-Muller
These are a range of inexpensive detectors which can also be quite hardy. They are particularly suitable for the detection of alpha, beta and – to a limited extent – gamma radiation. However, they are only limited in their detection of the latter (gamma radiation), so you should probably use a different portable detector for these rays. In general, these detectors can offer no spectral resolution which means that every single pulse reading will display the same height. - Scintillator
A scintillator is known for incredible gamma sensitivity, with a sodium iodide crystal mechanism that can give you a good spectral resolution when identifying isotopes. This is one of the best options for detecting gamma radiation, because it uses magnetically sensitive PMTs (stands for photomultiplier tube). - Solid State
Solid State devices can help in places where space is an issue, because these are very compact and small detectors. Their spectral resolution is particularly good when it comes to detecting isotopes. - Gas Proportional
These devices are excellent for detecting alpha, beta and neutron radiation. The problem is that the window of the machine is rather fragile, and there’s very little gamma sensitivity. At the same time, the pulse height is proportional to the energy detected: this makes it a good device for identification and detection of radiation energies. - Ion Chambers
These are chambers with an extended measurement range, so they allow you to see beta and gamma radiations easily. This is a good device especially for gamma radiation if you find a pressurized type of device. It is, however, rather difficult to use and maintain.
An Elementary Guide to using a radiation meter (typical)
- Ensure that the audio is switched on and the Fast or Slow setting is set to F (Fast).
- Put the instrument on and check that the batteries are operational.
- In case there is a radiation check source available nearby, ensure that the device works.
- Now, change the range to that of the lowest available scale and gradually find the correct scale, in order to check the background.
- Approach the source, and while you do so, change the range to higher scales if you think necessary.
- After this just position the instrument (front, bottom end) to the source of radiation (or possible source of radiation) in order to check the detection.
- Use manual if you want the most sensitive use.
Final Words of Advice on Portable Handheld Radiation Devices
If you are measuring radiation which reads above 1000 microR/hr, then you should limit the exposure immediately by stepping back. If you get readings of 2000 or more, stop measuring and call the Radiation Safety Officers, State Health department, and any other regulatory bodies. Otherwise, portable detectors are perfectly safe in themselves to use.