Geiger Counter Radiation Detector- Handheld Rechargeable Beta Gamma X-ray Radiation Meter Dosimeter, RM 9000 Giger Counters Nuclear Radiation Detector with High Sensitivity Preset Alarm LCD Display

The radiation monitor fits in my hand and has a length and width similar to a common smartphone but I would say it’s three times thicker than one. I received mine with the two required AA batteries already installed. The brand name of the batteries is Warriors with the expiration stamped on it.The monitor’s LCD display has four different colors – black, white, green and red. It tells me the time, however, I have to set it anew after every shutdown. The display also indicates the battery charge in the upper right corner, the current radiation reading prominently in the middle with a graph showing radiation over time. Above the current reading, to the right, I can see at what level of radiation the alarm is set. And left to the alarm value is the highest measured radiation level displayed in either a green background when it is below respectively in red when it is above the set alarm level. By the way, I noticed the background changes either to green or red when you change the alarm level depending on whether the new alarm level is either below or above the highest measured radiation level. I had to figure this out myself as it was not detailed in the manual.The manual is very short but in decent English; I could understand the instructions and follow them correctly. It states that the monitor detects X, γ and hard β rays in microsieverts per hour. The measurement range is from 0.01 to 100 microsieverts per hour and the display is updated every second.I set the time by pressing the exit button and then the up and down arrow buttons to change the hour. When I reached the desired hour, I pressed the OK button. I applied the same procedure with the minutes and seconds. Once I pressed the OK button for the seconds, the time is set. Its displayed in 24-hour format. As mentioned, I have to set the time anew every time I turn the monitor on but it takes just a couple of seconds. Most of the time, I don’t set the time if I need a quick reading only.The display shows the radiation value in microsieverts per hour. I can set the value at which the alarm sounds by long-pressing the OK button and then use the up and down arrow buttons to increase respectively decrease by 0.05 increments. Unlike the time setting, I was relieved to see that the monitor remembers the alarm setting.If a reading goes over the the set alarm level,I put the monitor to the test by measuring the radiation of a 50-lb bag of potassium citrate. The reading went up slowly and then spiked at 0.42 μSv/h and stayed around 0.28 μSv/h with minor spikes.Yet, the main reason I used it was to test my granite countertop in my kitchen. I got concerned because according to the EPA, neither imported nor domestic granite products require radiation testing. If present, uranium, thorium or radium in granite will decay into radon, a colorless, odorless, radioactive gas that may cause lung cancer. I don’t understand this lack of oversight. I have a massive granite countertop in my kitchen where I spend much time each day preparing meals from scratch because of allergy reasons. I was afraid of being exposed to excessive radiation and radon from the granite. Fortunately, none of the spots I tested came even close to the 3.33 microsieverts level which is a level too high for my comfort and should be probably for everyone, too.

Geiger counters like this are "accurate" only within the loosest meaning of the word. There are resources on the internet that go into limitations of similar designs, so I cannot offer much encouragement in this respect.Some of its limitations can be overcome. First, battery life is poor (about 6 hours runtime). Second, it has no built-in memory, so even if you were able to change its calibration, this calibration would be lost on power off. Third, measurements are via an audible click (or beeps for higher-level radiation) and it has no way to extract measurements - you are left relying on the LCD display which is colorful - but limited to, "what you see is what you get."I modified it by adding an Arduino Nano to supply 3V power and connected the Nano to the internal buzzer to "calculate" counts, counts/hour and conversions to approximations of Seivert and Roentgen measurements via a Windows PC application. I added a graphical display and data logging to the Windows 10/11 program. This program includes rough calibration methods. The application will be available for free download from my website (search for hardandsoftware(dot)net), before the end of 2022.I enjoyed playing with it.

You never know what awaits us! This is always good to have!

I have no idea how to use this, it doesn’t come with instructions. I can’t google instructions because this actually doesn’t have a brand name on it. Very disappointed considering I paid over $60 for it.It’s definitely getting sent back.

As a nuclear expert I can say I bought this on a whim. I have numerous pieces of natural radioactive materials at my home that I use in lectures or presentations. However, I normally would borrow a radiation detection meter from work, but I recently retired and thought I'd get a small little detector for the demos. This meter fits the bill. The principles and materials used in its assembly and operation are well known. It functions easily and responds to my demonstration pieces accordingly, but I'm certain the readouts are not as accurate or the range of the instrument. Since, this is being used for a demo and not for a diagnostic or health related safety determination, it works as intended. I trust it to detect radiation, an increase or decrease in radiation and I'll leave it at that.

Not usable due to poor quality. Couldnt get a reliable reading period.

Absolutely not good for a novice. Instructions useless for the beginner. Returning.

It turns off after 10 seconds, not the batteries changed them.