There are 2 types of radiation in general: ionizing and non-ionizing radiation. Ionizing radiation can be expressed in numbers by instruments such as the Geiger counter, ion chambers, scintillators, dosimeter, etc. While non-ionizing radiation can be measured with EMF meter, Gauss meter, etc. Ionizing radiation is more dangerous than non-ionizing one; can cause cancer.
Geiger counter measures the amount of radioactivity by counting the particles that get into the sensor (Geiger Muller tube). This gas-filled type instrument, in turn, generates pulses that represent the amount of particles hitting the gas atoms inside the tube.
Basically, it measures in CPM (count per minute) or CPS (counts per second). With the correct algorithm, conversion to µS/hr or mR/hr will get the dose rate. Then, the dose rate multiplied by time will get the dose accumulation (Sievert/REM). This accumulated dose is very important to know the safe level of certain radioactivity.
Visiting a nuclear disaster site, working on a machine shop’s granite surface plate, cooking on granite countertops, living near a nuclear power plant, mineral mining, etc can be reasons you need a Geiger counter.
Granite can be a radiation source as it contains uranium, thorium, alpha particles, beta particles, and/or gamma rays. Decaying into Radon, Radon can cause lung cancer. Putting food on its surface, it will be contaminated. Radioactive contamination in water, food, people, etc is also a thing of concern as well.
If you are going to buying a Geiger counter to assess whether you are at a safe level or not, this post is for you. Many Geiger counters come with radiation levels and dose rate reading. Perhaps, one of these top 5 Geiger counters is your choice. As the Geiger counter is expensive, you have to know some major specifications to consider.
Top 5 Best Geiger Counter Reviews 2021
1. GQ GMC-600 Plus Geiger Counter [Best Overall]
When searching for the best Geiger counter, we have to focus on its main purpose which is to measure the amount of particles from radioactivity. In this case, the product we are searching must be very sensitive to detect alpha, beta, gamma, and X-ray.
Herewith, GQ GMC-600+ (not the GQ GMC-600 model) presents as the best Geiger counter product ever that we found after hours of searches, designed for the public at a relatively low price.
It uses LND-7317 pancake model tube as the sensor. You can look this tube covered with mica, located at the back of the GQ GMC-600+. Its wide diameter allows more space to let the particles come in. This sensor is very well-known for its excellent sensitivity to detect the big 4 radiations (alpha, beta, gamma, and X-ray) at the same time, better accuracy compared to LND-712 or SBT-11.
Alpha ray, beta ray, gamma ray, and X-ray have energy. Is your Geiger counter able to detect the low-energy alpha? This is to make sure that your counter scans the entire radiation. The following is the minimum of energy of alpha ray, beta ray, gamma ray, and X-ray that can be detected by GQ GMC-600 PLUS.
- Alpha 2.5 MeV
- Beta 50 keV
- Gamma & X-ray 10 keV
You have to make some research of the energy range of those 4 particles. As our reference said; you can read on the buying guide section, this device picks almost the entire energy except some of the very low energy X-ray. X-ray energy is 100 eV to 100 keV. While the minimum detectable of GQ GMC-600+ is 10 keV, so it only detects some range.
For sensitivity, undoubtfully this is the best amongst its competitors on the market. It’s able to detect very low alpha radiation. You could check the user reviews about they use it on granite.
Not only does it provide great sensitivity, but the display also shows easy-to-read reading. It shows 4 important readouts at the same time: the amount of particles per time interval (CPM), dose rate (µSv/h & mR/h), and warning notification (high/normal/medium).
- Measuring range of the dose rate:
- 0.001 – 4250 µSv/h
- 0.001 – ~425 mRem/h
- Measuring range of the CPM:
The display is also automatic to be vertical or horizontal. It comes with backlight for easy reading in dim environment. Displaying the data in graphic can be done by setting through the menu.
GQ GMC-600+ allows you to enjoy the measured data not only right on the device but also external device (computer). It has a single LED and speaker. The LED will blink and the speaker will sound if the radiation reaches the threshold level.
You could download the data being stored (logged) on the device into your computer using the GQ GMC Data Viewer Software. Realtime monitoring is also possible with this software.
The standard mini-USB port is visible on the side. Through this port, you can connect the Geiger counter to a computer for data transfer and charging. This port also allows connection to an external power connection.
The Li-ion 18650 rechargeable Li-ion battery is employed to charge power to the device. You can also use the non-rechargeable one but you have to make some adjustment on the settings.
All in all, GQ GMC-600+ has great sensitivity, an informative screen, data logging for further data processing, realtime data on computer, and most importantly affordable. For all the things this American-made GQ GMC-600+ digital Geiger counter can give, its price is really cheap. However, according to its manual, a completely charged battery can only last less than 5 hours of use. However, this drawback can be dealt with external power source. Perhaps, you want to monitor the radiation in your house or office, or school, the external power source can be used.
Read the manual here: https://www.gqelectronicsllc.com/GMC-600UserGuide.pdf
- Highly sensitive Geiger tube LND 7317
- Measures alpha (even the low alpha), beta, gamma, and some X-ray.
- Real-time graphical visualization mode is available to select
- Highly functional: easy to read, large screen, backlight, Wifi, data logging, rechargeable.
- Computer connection
- No way to indicate what radiation you are measuring, you measure all ionizing radiation
- Not IP rated, don’t let it wet, store in dry place.
- The software is for Windows only
- Short battery use (less than 5 hours)
2. Gamma-Scout German Made Geiger Counter (Last 10 Years)
The amazing this about the Gamma-Scout geiger counter is its battery power. It can last up to 10 years. If you search on Youtube, type in Gamma-scout, you will find people who review this measuring instrument from 8-10 years ago. Gamma-scout is insanely legend.
If you buy a Geiger counter for preparation, then this one might be no doubt to buy due to its battery life. Even it comes with completely no switch-off button. This device will keep counting anything (particles) in front of the sensor.
Geiger Muller Tube LND-712: Sensitivity & Durability
Gamma-scout makes use of the shaped-tube LND-712 Geiger Muller tube. This tube is able to detect Alpha, Beta, Gamma, and X-ray.
- Alpha: 4 MeV minimum
- Beta: 0.2 MeV (200 keV) minimum
- Gamma & X-ray: 30 keV minimum
If you think that the lowest alpha energy is
3 MeV 4 MeV, then this German-made Gamma-scout will detect alpha radiation in the entire range. But its spec for X-ray and beta is not really satisfying. It only covers down to 30 keV while low-energy X-ray can reach down to 100 eV (0.1 keV). Low energy beta can have 100 keV while the low detectable beta is only 200 keV.
Talking about sensitivity, this tube is not as sensitive as LND-7317 but it’s more durable. In some situations where durability is more important; if it’s broken and impossible to replace or fix, Gamma-scout is the winner.
Switchable Radiation Measurement
This is another great advantage of Gamma-scout. Unlike other Geiger counters that are not able to distinguish which radiation they are counting, this Gamma-Scout gives you a switchable ray measurement. It’s through its ray selection switch that you can see on the upper part of the instrument. Herewith, you know what radiation you are measuring.
- Left. Turning it left will make the counter tube window covered by aluminum foil (0.1 mm). As a result, it enables gamma and beta measurement only. Meanwhile, the alpha particles are not able to pass through.
- Center. Keeping it at the center will make the counter tube window covered by an aluminum plate (3 mm, thicker) and lead (50mm). In turn, it only enables gamma rays to pass through. While the alpha and beta are not able to enter.
- Right. Lastly, turning it right will let all the particles come in. In this case, you can measure all the particles (alpha, beta, and gamma). If you are going to measure alpha and beta, make sure to put the device close to the source.
There is no fancy display but it fulfills its main function for displaying some important information. It displays the particle rate (CPS), dose rate (µS/h or ), accumulated dose (µS or R). The accumulated dose is an important function to know how many radiations the device gets.
The measurement readings are automatically stored in the internal memory. These readings can be downloaded and analyzed on your PC through its GAMMA-SCOUT® TOOLBOX software. This software is installable both in Windows and Mac-based.
- Measuring range of dose rate:
- 0.01- 5,000 µSv/h
All in all, Gamma-Scout is incredible for long-term use. For radiation detection, this model is highly reliable. Its battery lasts for years. The system only consumes very little power. Imagine that the device will be always on for 10 years nonstop serving you with radiation information of surroundings. In our perspective, Gamma-Scout is appropriate for preppers due to its ability to last for years.
Even, when the battery power is low, you can recharge it. Among the 4 models you can pick, this one is rechargeable. You don’t need to desolder to replace the battery.
Moreover, you can download the data and analyze it both in Windows and Mac. In contrast, GQ GMC-600+ above provides for Windows only.
The ability to measure cumulative dose (becomes dose meter) makes it another reason to buy. GQ GMC-600+ has no this function. So, if you put this Gamma-scout in a specific site, let it measure all the time, you can estimate how many doses you will get if you stay at the same site as the device lies on.
The drawback is Gamma-scout doesn’t cover completely alpha and beta radiation measurement. Its sensor is not as sensitive as the GQ GMC600+ sensor. While it’s highly reliable for detection, it’s not for better accuracy measurement.
- Lasts for up to 10 years under normal use, plus rechargeable
- Able to distinguish what particles being measured
- Data logging
- Dose accumulation measurement is available
- Computer connection
- The software for data analysis can be installed both in Windows and Mac
- Doesn’t cover the entire alpha and beta particles’ energy energy
3. Mazur Instruments PRM-9000 Geiger Counter
Instead of using a fancy display like the GQ GM600+ that requires more power to run, perhaps you need something that is simple, more accurate but lasts longer. These specifications are needed if you want to use it in a place that power consumption really matters (some places out there). Mazur PRM-9000 is a combination of high sensitivity LND-7317 sensor and longer battery use up to 3 years that will fulfill your need.
Mazur PRM-9000 Geiger counter uses pancake model LND-7317 Geiger muller tube as the sensor. As we know, this sensor measures alpha, beta, gamma, and X-ray; the four big radiation. For low energy alpha particle detection, the spec is fully capable as well as for beta and gamma particles. However, according to spec, this sensor is weak to detect very low X-ray radiation. It is only able to detect X-ray radiation that has energy from 10 keV – 100 keV.
- Alpha: minimum 2.0 MeV;
- Beta: minimum 0.16 MeV (160 KeV)
- Gamma & X rays: min 10 keV
Battery and External Power
Both battery and AC power can be the power source of this instrument.
For battery, the 9V alkaline battery is the default. Nicely, the 9V Lithium battery can be another battery option for you. Alkaline leaking may be your reason. The lithium one can provide 60,000 hours which is equal to 6.8 years of battery life.
Though having a good low power consumption to last longer, you could make use of external power source. There are two ports on the side of this instrument. You could connect an A/C adapter to the bottom port to use external power.
Elapsed time in second minute hour day. Current reading, average reading, maximum reading, minimum reading, total count, the day when the maximum reading detected, and time. The reading can be in particle rate (CPM or CPS) and dose rate (µR/hr, mR/hr, or µSv/hr). No dose exposure reading.
- 0.001 – 125 mR/hr or 0.01 – 1.250 µSv/hr
- 0 – 300,000 CPM or 0 – 3,000 CPS
This instrument’s logged readings are also downloadable from the internal memory. You can connect this device to the computer through the upper port and turn the logged readings in CSV format. For realtime monitoring purpose on computer, the pulses will turn into graphics through this port. Working silently is also possible. This port can be connected to earphone.
All in all, Mazur PRM-9000 is indeed more expensive than GQ GMC-600+ but Mazur is possible to carry along to some place out there (perhaps near a nuclear power plant, rock mining, etc) and use it for longer time. Both of them use the same sensor. On the other hand, compared to Gamma-scout, PRM-9000 is the winner in terms of better sensitivity for radiation detection.
The only drawback that we discover is its display. It looks outdated and small. But it should be okay if luxury display is not your priority.
- LND 7317 two-inch pancake GM Tube
- Sensitive to alpha, beta, gamma, and X-ray
- Pretty long battery life (up to 4 years)
- Dose exposure measurement
- A little bit heavier than other Geiger counters: 13.0 ounces
- Less infomational display
4. GCA-06W Professional Geiger Counter with Probe
Looking for the Geiger counter with an LND-712 sensor but more cost-friendly than Gamma-scout? GCA-06W is the answer. The sensor is built in the probe so you can make sure the device doesn’t contact to the object you suspect radioactive.
The separated probe unables you to cover it with a specific material such as paper, aluminum foil, and lead to indicate what radiation you are intending to block.
According to the company description of the detector/sensor sensitivity:
- Alpha above 3.0 MeV
- Beta above 50 KeV
- Gamma & X-ray above 7 KeV
This coverage sounds great. However, as we know, the sensitivity of LND-712 is medium level. It’s not as sensitive as LND-7317 but better durability.
The toggle switches may look old-school style but they are made straightforward and clear to instruct. The functions are on/off device, on/off sound, on/off backlight, particle counting toggle (CPS/CPM/Average CPS), and dose rate toggle (mSv/hr, mR/hr). Pulse indicator blinking LED, low battery LED, Headphone, data output, and external power ports are also available. The data output port allows you to enjoy a wider view of the radiation readings on computer.
- 1.0 µR/hr – 1000 mR/hr
- 0.01 µSv/hr – 10 mSv/hr
If you need a Geiger counter instrument that is calibration documented, then this is the option you can pick. In this case, an additional cost charges you.
- It comes with a probe; the device doesn’t contact the radioactive object
- Easy to use
- LND-712 GM tube but affordable
- Computer connectable using the data output port
- An external power port is available
- The toggles are not suitable to bring in a tight bag
- Requires decent electronics knowledge to connect the device to a computer
5. Soeks 112 Compact Geiger Counter for Travel
If you travel a lot, you need something that is compact. Soeks 112 can be your personal radiation warning that you can put in your pocket and carry along. You can easily instantly assess the dose rate of your travel with it.
It uses SBM20-1 Geiger muller tube. Thus, we are impressed with its size. Many DIY Geiger counters with this sensor don’t have this tubular size. Though small, as consequence, it’s not able to measure alpha radiation, only for beta and gamma radiation. If you think you don’t really close (few centimeters) to alpha radiation source, you are sure that you don’t inhale it nor eat it, this is a great pick.
The reading is µS/h. The measuring range is 0.01-999 uSv/h. It produces a click sound along with a red flash whenever exposed to the environment having a radiation level above the normal range. Also, you can easily configure the threshold for background radiation and a level to get notify (alarm) when reached. The CPM/CPS reading is none which is a drawback.
Its power comes from the small 2 × LR44 batteries. This battery should last more than 100 hours. In case you expect to use it longer, you can buy the backup.
Soeks 112 is great to use as a detector. Whenever you visit a certain site you concern there is radioactivity, this small-sized compact Geiger counter will fit in your pocket. Ready to go anywhere. Its price is also friendly.
- Pocket size, ready to carry in the pocket
- SBM20-1 Geiger muller tube: beta and gamma
- Adjustable warning level
- No CPM/CPS reading
- Small LCS screen display
- Not measure alpha radiation
Things to Consider Buying A Geiger Counter
1. Capability to Measure the 4 Radiations
The best Geiger counter should be able to detect and measure the 4 radiations: alpha, beta, gamma, and X-ray. Some counters are only able to detect beta, gamma, and X-ray. This limitation is commonly the factor of the sensor/Geiger Muller tube. Different GM (Geiger Muller) tube models will have different capabilities.
2. Detector Sensitivity
Even though it’s able to cover the 4 radiations, the sensitivity may be different.
A Geiger counter will be called sensitive if it can count more particles compared to the other counters. For example, higher sensitive Geiger counter A counts 1000 particles while the B counts only 500 particles even though they measure the same object for 1 hour.
When talking about detector sensitivity, we are talking about the tube as well. There are 4 common tube models on the markets: LND-7317 (American made), LND-712 (American made), SBT-11 (Russian), and SBM20-1 (Russian).
The LND-7317 pancake-shaped is the highest sensitive but easy to break. LND-712 short-tube-shaped measures alpha, beta, gamma, and X-ray but less sensitive than LND-7317. The SBM20 long tube-shaped detects
alpha, beta, gamma, and X-ray. Lack of alpha detection makes this sensor not suitable for most uses. Compared to LND-712, the SBM20 is less sensitive and more fragile.
It’s also important to know the specification of the sensor. Alpha, beta, gamma, and X-ray particles come with a certain energy. The summarize of each radiation energy can be expressed in a range and the unit is eV.
- Alpha: 4 – 12 MeV; alpha particles from Nd-144, Hf-174, Te-108 are less than 4 MeV (Table of isotopes)
- Beta: 100 – 800 keV; beta particles from C-12 and Tritium are less than 100 keV (radioactivity.eu.com)
- Gamma: more than 100 keV (Arpansa.gov.au)
- X-ray: 100 eV to 100 keV (Arpansa.gov.au)
By knowing their energy range, we know the GM tube spec that we require.
3. Purpose of Buying
The people who want to check the radiation from a nuclear plant (because they live near it) should buy a Geiger counter for continuous monitoring. In this case, you don’t the one able to pick alpha.
But for people who want to detect and measure radioactivity of rocks, antique watch, antique ceramic, etc, an accurate Geiger counter that covers the 4 radiations are required.
4. Battery / Power
Measuring radioactivity somewhere far out there requires 4 radiation coverage and lots of power consumption. Preppers would take this factor as big consideration.
While measuring in the house, office, school, or lab you can make use of AC power. In this case, an external power port and an additional AC adapter are necessary.
5. Data Transfer
If the instrument can store the measurement readings in its internal memory, it’s good. Especially if it’s downloadable too. That means you can move it from the internal memory to your computer for further processing. It can turn into graphics, spreadsheets, etc. In this case, a special data output port is necessary. It’s not weird if you have to install a particular software on your computer to process the data. Even you can connect the two devices to see the measurements in real-time mode.
6. Dosimeter Feature
If your Geiger counter is able to convert the reading into dose accumulation (Sievert), it’s a plus point. To properly measure the dose rate that your body receiver, make sure the geiger counter is put at chest/waist level and/or distanced apart one foot from the ground.
How It Works
The name Geiger counter may/does come from the way it works. It employs the Geiger Muller tube as the sensor. The tube is filled with a certain gas.
This gas cannot get out from the tube but the particle from radioactive elements can enter and hit the gas atom. The particle being said is Gamma. While alpha and beta need to enter from the tube window. This window is covered with mica. The mica allows all the particles to enter but it prevents the gas from get outside.
Some products can even prevent the alpha particle or alpha and beta particles from entering the tube. In this scenario, perhaps the mica is doubled behind with aluminum foil (for alpha) and a thicker aluminum plate (for alpha and beta).
Electrodes are employed to support in making pulse. While the particles enter the tube and hit the gas atoms, the positive ions are attracted to anode electrode while the negative ions are attracted to katode electrode. The potential voltage happens and generates pulse. Pulse is turned to sound by electronic circuit.
DIY Geiger Counter
You can do it. The sensor you can buy is either SBM-20 or LND-712 or LND-7317.
How to Calibrate Geiger Counter
You can use Cs-137 as the standard. In this case, you have to calculate how many particles that your Geiger counter measures in comparison with the number of particles you should measure.
Your GM should measure 1000 particles, in fact, you get the reading of 900. That means your error is 10%. Whenever you measure with your GM, subtract the reading by 10%, you are closer to the true reading.
This way is what you can do in-home at a low price.
You could also pay a calibration company to calibrate your Geiger counter to at least a NIST traceable standard. This way is recommended for industries.
This is the example of a calibration certificate https://www.imagesco.com/geiger/pdf/certification.pdf
Can I Measure Radon with Geiger Counter?
Geiger counter is not designed to measure Radon but it can give a sign of the existence of Radon. Radon gives off alpha particles. Therefore, your Geiger counter must be able to measure Alpha radiation.