5 Best Geiger Counters

Simply put, a Geiger counter is used to detect radiation. While you may think of a Geiger counter as simply a science fiction trope or a must-have dust collector on a survivalist’s shelf, there are a number of practical reasons why you might want to purchase one.

With a Geiger counter, you can keep tabs on radiation in your food, water, and home. It is a necessity if you live near a nuclear reactor, and rockhounds or those interested in science will find any number of fun ways to use one. Those into collectibles will also find a use for a Geiger counter because the level of radiation in older glassware, clocks, and other collectible items can be fairly significant.

If you need to know the level of radiation in various items, you’re going to need to know the ins and outs of this unique device. 

Because this is a device that you may have to take with you, all elements of a Geiger counter should be durable and long-lasting. The housing — plastic is standard — should hold up over time. Any buttons or switches should be able to withstand a fair amount of use, and any display screens should be firmly fixed to the housing and resist cracking. If your Geiger counter will be used outside frequently, try to find one that is either waterproof or can otherwise hold up to various weather conditions.

In the movies, Geiger counters tend to be bulky, about the size of a shoebox. In real life, they aren’t nearly so cumbersome. Geiger counters vary a bit in size, but most today are lightweight and roughly the size of a smartphone. The lighter and more compact your Geiger counter, the easier it will be to carry around.

Based on their size, it should be no surprise that most Geiger counters run on batteries. Some use disposable batteries (9 volt or AA/AAA), while rechargeable batteries are more standard.

Disposable: If the Geiger counter uses disposable batteries, find out if it ships with the batteries, and how long on average the batteries will last before they need to be replaced.

Rechargeable: If it uses a rechargeable battery, you need to know how long the charge lasts and how long it takes to recharge. Does it charge via AC, USB, or your car? Some offer a variety of recharging options, but whichever way a Geiger counter is charged, be sure it ships with all the cords necessary to recharge or power it.

For a number of reasons, some Geiger counters are easier to use than others. A Geiger counter that is ergonomic and can be operated with one hand will be easier to use than a bulky one that takes two hands to run. The addition of a wand allows you to more easily take readings of items.

Controls like buttons and switches for changing modes and settings can enable more fluid operation, as opposed to scrolling through multiple menus on the LCD screen. Look for a Geiger counter that presents the information in such a way that you can tell at a glance what an item’s radiation level is.

Finally, a Geiger counter is only as accurate as its calibration, so know how often you’ll need to recalibrate it and how easy or difficult this process is.

While all Geiger counters can read radiation levels, most of the higher-quality ones are also capable of doing much more with the data they collect. This is often helped via software or an app that installs on your computer or smartphone, allowing you to link to the Geiger counter to graph data over time, receive alerts, share your readings with others, monitor levels, and more. If a Geiger counter ships with this capability, verify that any software or app will work with your specific operating system (type and version). Also be sure that the Geiger counter ships with all the cables you’ll need to link up with your computer or phone.

Type: Alpha, beta, gamma, X-ray — top-shelf Geiger counters are capable of detecting a variety of radiation types, but cheaper models will vary in what they can detect. Nearly all can detect gamma rays and X-rays, and most can also detect beta rays. Alpha-ray detection is rarer and usually only available in more expensive Geiger counters.

Range: You should also know the range of radiation that a Geiger counter can detect. Digital Geiger counters can usually detect 1 to 200 milliroentgens per hour (mR/hr), although more expensive devices can reach up to 1,000 mR/hr.

Geiger counters in the movies start to emit a ticking sound in the presence of radioactivity. The faster the tick, the closer or more powerful the radioactivity. Similarly, today’s Geiger counters also alert you to the presence and location of radiation, but they aren’t limited to sound. Some Geiger counters use LED lights to warn you when they have detected radiation, while others vibrate. Before purchasing, know what kinds of alerts the Geiger counter uses and if you can switch between them. Being able to adjust the volume or intensity is also helpful.

A Geiger counter that includes a wand can be easier to use due to the fact that a wand can reach into tight spaces more easily to take a reading. The wand contains the Geiger-Müller tube, a sensing element that is an integral part of any Geiger counter. If a Geiger counter doesn’t have a wand, then the Geiger-Müller tube is inside the device’s housing. If the Geiger counter you’re interested in has a wand, be sure that it’s rugged and has some way of clipping to the Geiger counter’s housing for easy storage.

Most Geiger counters are digital and have an LCD screen for displaying the counts per minute/second, radiation levels, and other information. A Geiger counter’s LCD screen should be large enough so that you can clearly see and understand the information you need. A backlit screen is easier to read than one without backlighting. The ability to zoom or manipulate the font size will also be a big plus for some users.

Controls: The controls vary by device, but most Geiger counters offer some way to switch between type (metric, imperial), counts per minute and counts per second, on and off, and more. Some Geiger counter controls have computerized menus for changing settings, while others rely on buttons and switches.

Ports: Check if the Geiger counter you’re interested in has a speaker/headphone port and a data output port so you can use it with your computer.

Geiger counters start at less than $100 and can go up to $400 or $500 for high-end consumer devices. Under $150, you’ll find lower-end devices with limited ranges, features, and other capabilities. Spend over $150 and you’ll find Geiger counters that can detect more radiation types at a wider range, sturdier build quality, and much more robust software/sharing capabilities that allow you to do more with the data you collect. 

Q. What’s the best way to test for radiation in food?A. While you can use a Geiger counter to test for radiation in fish and other foods, you shouldn’t necessarily rely too much on the results. Because the radiation readings in foods can be miniscule and blend in easily with background radiation, tests of this nature are usually done in a lab. That said, if you do wish to use your Geiger counter on food, do it the right way. Instead of a single apple, say, test a bushel of them. For best results, turn the Geiger counter on and place it close to the food, leaving it for a minute to generate a solid reading. Do this several times in different spots around the food to increase your chances of ending up with an accurate reading.

Q. Do Geiger counters emit radiation? Are they safe?A. While Geiger counters can detect a variety of radiation types, they do not themselves contain or emit radiation. As such, they’re perfectly safe to use and carry around in your pocket.

Q. Can my Geiger counter be used to detect a microwave oven leak?A. No. Geiger counters can detect ionizing radiation, such as that emitted by uranium. While microwaves, cell phones, and similar items do produce radiation, it is of the nonionizing variety. To detect this form of radiation, you’ll need to buy an electromagnetic frequency (EMF) meter.