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Electronic vs. Passive Dosimetry: What is the Difference?

In work environments where exposure is always a risk, the ability to measure the amount of radiation absorbed by the human body is vital to the safety of personnel. This measurement is performed by personal dosimeters – devices that are worn or carried by workers to measure radiation levels around them.

However, different environments call for different protocols when it comes to radiation exposure. To address these separate needs, dosimeters come in two types: electronic and passive.

What are electronic dosimeters?

Electronic or “active” dosimeters measure radiation levels in real time and alert the wearer when they are approaching elevated or dangerous levels of exposure. They also show an estimate of how much radiation the wearer has accumulated. This type of dosimeter is helpful for environments where radiation levels are fluctuating and can rapidly become dangerous.

Explore other examples of Electronic Dosimetry Systems »

Where are electronic dosimeters used?

Personal electronic dosimeters are used for situations where high levels of radiation can be expected, such as nuclear power plants, nuclear accidents and military operations. In emergency or high-exposure scenarios like these, it is critical for personnel to be able to monitor their surroundings in real time. Electronic dosimeters help emergency responders complete their tasks by keeping them actively informed about their radiation exposure and giving them an idea of how long they can stay in a hazardous area.

What are passive dosimeters?

Passive dosimeters record how much radiation a person absorbs over a set period of time, such as a week or a year, so they can later be collected and analyzed. They are “passive” because they do not need to be continuously monitored. Workplaces that include regular exposure to radiation have set limits on how much a person can absorb before it begins to affect their health, and passive dosimeters help to keep personnel below that limit. Passive dosimeters are also known as occupational dosimetry because they are utilized for legal dose recording and compliance with regulations.

On-demand dosimeters

Mirion Dosimetry Services has innovated a third type of dosimeter, the on-demand dosimeter that sits in between electronic and passive. Like passive dosimeters, on-demand dosimeters continuously monitor cumulative doses and show data after exposure rather than in real time. The difference is that dose data for on-demand dosimeters can be read and accessed much sooner than traditional passive dosimeters. They have the speed and self-process capability of an electronic dosimeter, tailored to the purposes of a passive dosimeter. This gives the wearer a higher level of flexibility in determining when and how often they can manage their occupational exposures to regulatory limits.

Where are passive and on-demand dosimeters used?

Passive dosimeters are worn in workplaces that are regularly exposed to low levels of radiation, such as research labs and doctor, dentist and vet offices. The most commonly used passive dosimeters are film badges, thermoluminescent dosimeters (TLDs), and direct ion storage (DIS) dosimeters. By the end of a certain time frame, these dosimeters are collected and analyzed to ensure that radiation levels are not accumulating to a dangerous degree.

TIP: When dealing with radiological hazards, different situations require different safety measures. It’s important to stay informed on the best ways to monitor exposure levels in your environment or industry.

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