Radiation is colorless, odorless, tasteless, soundless and lacks any type of tangible “feeling.” As a result, it’s nearly impossible – save an acute event resulting in immediate physical damage – for individuals to know they are exposed to radiation at all. If you work in a radioactive career, your company safety culture matters.
It’s your company’s – and the radiation safety officer’s (RSO) commitment to ALARA – including adequate detection and measurement technologies that will keep you and other employees safe.
How is Radiation Measured?
Radiation is present in our environment, the earth, outer space and even in our homes. This is because radiation is a natural phenomenon. As such, humans and other living organisms can withstand small doses, over time, with zero to minimal health risks. It’s only when those radiation doses creep up into the larger limits, are at closer proximity and/or exposure occurs over a long-period of time that radiation poses a serious risk.
For this reason, nuclear plants, industries that work with radioactive materials, and individuals who work or live within close proximity to radiation, should ensure proper measurement and detection protocols are put in place. Industry-respected, high-quality radiation instruments are the only means of telling whether or not there is a potential risk from radiation (over) exposure to yourself and others.
How to measure a radiation dose rate
The first thing to note is that not radiation detectors are not created equal. Some measure contamination, some only measure specific types of radiation, and others only tell you the type of radiation the instrument detects. If you’re worried about radiation sickness or being poisoned by radiation, you need an instrument that more specifically measures radiation dose rates, so you can respond accordingly.
The Geiger Counter is the first instrument laypersons think of when they hear radiation detection or measurement device because we learned about it back in earth science. However, it’s not always the best choice. The average Geiger counter will go haywire and yield an inaccurate high reading when hyper-responds to low-energy gamma rays that comprise the majority of natural background radiation, and it will give an alarmingly low reading if you’re attempting to measure radiation from high-energy gamma rays.
The best Geiger counter for measuring radiation dose rates is one that is what we call “energy compensated.” Energy-compensated Geiger counters are designed to make up for those differences. Even so, we don’t consider these to be the most effective way of accurately measuring specific radiation dose rates.
Ion chambers, or similar pressurized versions that can measure really low radiation dose rates, are basically chambers filled with gas. The electrical properties of the enclosed gas change whenever radiation passes through the chamber. By measuring these electrical changes, we can tell how much radiation the ion chamber is exposed to. Radiation dose rates are measured in milliRoentgen per hour, or mR/hr.
How to measure radioactive contamination
While you may breathe a sigh of relief when the ion chamber indicates a low radiation dose rate, that doesn’t mean you’re off the hook. There could be radioactive contamination that needs to be addressed. This is important to note because if and whenever possible, radiation contamination should be cleaned up.
For example, after a nuclear reactor accident, distant areas may have low radioactive dose rate measurements while still reading positive for nuclear contamination. Why leave radioactive materials in and around the earth if we don’t need to?
In this case, as touched on above, Geiger counters are the perfect instrument to use. More specifically, you can use a pancake GM, a specific type of Geiger counter to measure contamination – which is measured in counts per minute, or CPM.
How to Measure Different Types of Radiation
There are four different types of radiation: alpha, beta, gamma and neutron. Since each one has different properties, each one of them is measured a bit differently.
- Alpha radiation is measured by a GM pancake probe or a zinc sulfide scintillator
- Beta radiation is measure using a GM pancake probe, a beta scintillator or an ion chamber
- Gamma radiation is measured by a GM pancake probe, a GM hot dog probe, a sodium iodide scintillator or an ion chamber.
- Neutron radiation is most commonly measured using a scintillation detector and specialized detection software.
Do you work in a radioactive career or employ others who require specialized radiation protection? Contact us here at Lancs Industries. We design and manufacture leading radiation shielding and protection products, including glove bags and sleeving, to increase the safety of workers in potentially hazardous environments. We can also design custom equipment, clothing and products.
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