---
product_id: 829250
title: "MONITOR4 Analog-Based Ionizing Radiation Detector"
brand: "radiation alert"
price: "€ 10.81"
currency: EUR
in_stock: false
reviews_count: 8
url: https://www.desertcart.nl/products/829250-monitor4-analog-based-ionizing-radiation-detector
store_origin: NL
region: Netherlands
---

# Three selectable ranges Dual-scale analog meter Detects alpha, beta, gamma MONITOR4 Analog-Based Ionizing Radiation Detector

**Brand:** radiation alert
**Price:** € 10.81
**Availability:** ❌ Out of Stock

## Summary

> 🔒 Safeguard Your Space: Know Before You Go!

## Quick Answers

- **What is this?** MONITOR4 Analog-Based Ionizing Radiation Detector by radiation alert
- **How much does it cost?** € 10.81 with free shipping
- **Is it available?** Currently out of stock
- **Where can I buy it?** [www.desertcart.nl](https://www.desertcart.nl/products/829250-monitor4-analog-based-ionizing-radiation-detector)

## Best For

- radiation alert enthusiasts

## Why This Product

- Trusted radiation alert brand quality
- Free international shipping included
- Worldwide delivery with tracking
- 15-day hassle-free returns

## Key Features

- • **Stay Informed:** Monitor ionizing radiation levels effortlessly.
- • **Versatile Use:** Ideal for labs, industrial settings, and safety checks.
- • **Instant Alerts:** Flashing counter and beeping for immediate awareness.
- • **Precision Display:** Needle-point analog meter for accurate readings.
- • **Customizable Sensitivity:** Three operation ranges for tailored detection.

## Overview

The MONITOR4 Analog-Based Ionizing Radiation Detector is a sophisticated tool designed to measure potentially harmful ionizing radiation in various environments. It features a dual-scale analog meter for precise readings, customizable sensitivity with three operation ranges, and immediate alerts for increased radiation levels, making it essential for safety in industrial and laboratory settings.

## Description

The Radiation Alert Monitor 4 is a hand-held radiation detector with an analog display over three selectable operational ranges for detecting potentially harmful ionizing alpha and beta particles, and gamma and x-ray radiation. This meter has a dual-scale, analog, needle-point display of counts per minute (CPM), and milliRoentgen (mR) per hour. It detects the four main types of ionizing radiation: alpha and beta particles, and gamma rays and x-rays. It has three selectable operational ranges (X1, X10, or X100) to be adjusted when the meter face peaks at the highest mR level. The Monitor 4 has a red, flashing counter and a beeping noise to indicate each ionizing radiation event. It has a halogen-quenched Geiger Mueller (GM) tube with a thin, mica end window for sensing ionizing radiation. It is used to check radiation levels in the environment and objects, such as particle accelerators, x-ray shielding, and industrial gauges. An audio indicator with an internally mounted beeper can be turned off for silent operation. The Monitor 4 cannot be returned.Specifications Reading Ranges 0 to 0.5, 0 to 5, or 0 to 50 milliRoentgen (mR) per hour, or 0 to 500, 0 to 5,000, or 0 to 50,000 cycles per minute (CPM). Accuracy Factory-calibrated by pulse generator, with accuracy + or -15% of reading full-scale, relative to Cesium 137. Energy Sensitivity 1,000 CPM/mR/hr (Cs137). Detection Alpha down to 2.5 mega (million) electron volts (MeV), with typical detection efficiency at 3.6 MeV at greater than 80%. Beta at 50 kilo (thousand) electron volts (keV) with typical 35% detection efficiency. Beta at 150 kilo (thousand) electron volts (keV) with typical 75% detection efficiency. Gamma and x-rays down to 10 keV typical. Temperature Range -20 degrees to 55 degrees C (-4 degrees to 131 degrees F) and an internal detector. GM Detector Halogen-quenched with window thickness of 1.5 to 2.0 mg/cm2. The effective diameter is 0.92 cm/0.36”. Dimensions Dimensions are 209 mm x 71 mm x 50 mm (8.2” x 2.8” x 1.9”). Weight 178 g (6.3 oz). Output 3.5 mm headphone jack for use with observer software (not included) and Windows-based computers. Normal Background Radiation Approximately 5 to 20 CPM. Battery 9-V alkaline battery (not included) for approximately 2,000 hours of continuous use in a normal background. Radiation detectors can detect a broad range of ionizing alpha and beta particles, and gamma and x-rays that may be emitting harmful levels of radiation. They sense ionizing radiation with an enclosed Geiger Mueller (GM) tube to count radiation particles or rays. Alpha and beta particles are measured in counts per minute (CPM) or counts per second (CPS). Gamma rays and x-rays are measured in milliRoentgens (mR) per hour, microSieverts (μSv) per hour, or milliSieverts (mSv) per hour. Alpha particles are positively charged and heavier than beta particles, and have a limited range of approximately 3 to 5 centimeters by air. Alpha particles can be shielded by objects such as paper and unopened skin. High-energy beta particles are electrons, heavier than gamma rays, and can take either a positive or negative charge. Beta particles can be shielded by aluminum or wood. High-frequency (short wavelength) gamma rays are the strongest and lightest rays. Gamma rays are more penetrating than alpha and beta particles. They can be shielded by dense materials such as lead, and large masses of concrete, hardened steel, or water. X-rays are man-made gamma rays, and have essentially the same properties and function. Radiation detectors commonly have either an analog or a digital display. Analog radiation detectors output with a needle-point scale, and digital units generate a numerical LCD digit display. Radiation detectors are commonly used by hobbyists for safety detection and rock inspection, and professionals in the in the nuclear, medical, mining, instructional, and research industries.SE International manufactures radiation detection products and accessories under the Radiation Alert brand. The company was founded in 1979 and is headquartered in Summertown, TN.What’s in the Box?Monitor 4 radiation detectorCarrying case with belt clipInstruction manualConformite Europeene (CE) certification

## Features

- Radiation detector used to check levels of potentially harmful ionizing particles and rays in the environment and in objects such as particle accelerators, x-ray shielding, and industrial gauges
- Detects ionizing radiation types such as alpha and beta particles, and gamma rays and x-rays
- Dual-scale analog meter with needle-point display of counts per minute (CPM) and milliRoentgen (mR) per hour
- Three selectable operation ranges of X1, X10, and X100 for adjustment when peak mR levels are met
- Red, flashing counter and a beeping noise indicate each ionizing radiation increase event

## Images

![MONITOR4 Analog-Based Ionizing Radiation Detector - Image 1](https://m.media-amazon.com/images/I/71V8Ji6jnqL.jpg)
![MONITOR4 Analog-Based Ionizing Radiation Detector - Image 2](https://m.media-amazon.com/images/I/61tCiMZTmEL.jpg)
![MONITOR4 Analog-Based Ionizing Radiation Detector - Image 3](https://m.media-amazon.com/images/I/61sHMyuD-RL.jpg)
![MONITOR4 Analog-Based Ionizing Radiation Detector - Image 4](https://m.media-amazon.com/images/I/51kgQ-b43nL.jpg)
![MONITOR4 Analog-Based Ionizing Radiation Detector - Image 5](https://m.media-amazon.com/images/I/41-Q7fNflSL.jpg)

## Customer Reviews

### ⭐⭐⭐⭐⭐ Excellent geiger counter for the money.
*by G***T on October 8, 2011*

I recently purchased the Monitor 4 geiger counter due to the ongoing nuclear crisis in Japan. I have been very pleased so far. It is very sensitive, accurate, durable and easy to use. Plus, the price is fair. I strongly recommend anyone who purchases this geiger to also purchase the Observer geiger software Radiation Alert OBSERVER Software For Collecting Counts From Radiation Detectors. When used together with the software, it turns the Monitor 4 into a very capable instrument. I have been using both together to check for low-levels of food and drink contamination. It has been very useful so far. I have also owned the Inspector+ geiger counter. That geiger counter has a super-sensitive pancake sensor. Only a 10-minute count is required for that instrument to get a fairly accurate reading of low-level contamination. BUT the same thing can be accomplished with the Monitor 4 when used with the Observer software. This can be done by taking a longer timed count of at least 20 minutes (but 30 minutes to 1 hour is even better). The reason the longer timed count is necessary is because the Monitor 4 has a much smaller sensor compared to the Inspector+. But in the end the same thing can be accomplished when used with the software. Plus the Monitor 4 is in stock NOW. The Inspector+ is back ordered everywhere by at least 6-12 months. You really can't go wrong with the Monitor 4 when used with the Observer software. It is a reliable, accurate, and durable instrument that will last many years. Just ask the owners of the older design Monitor 4.

### ⭐⭐ Analog needle display not useful under ordinary conditions
*by B***B on November 11, 2013*

The product is described as registering 5 to 20 CPM (counts per minute) "normal background radiation". This is how many clicks or beeps you'll get when you use the meter without any radioactive sample nearby, for instance if you are trying to detect food contamination. However, the analog needle display will not distinguish between these values. The most sensitive setting has the display read between 0 and 500 CPM, but at 5 CPM the needle will jump up a tiny bit and slowly drop back to zero after each particle is detected. You would need to connect the device to a computer in order to get such a sensitive reading. Such a reading would be made using software to count events over several minutes or an hour.It's nice that the meter has a headphone jack, which is a bit easier to interface a computer to than USB. It's also nice that the product specifications for the GM tube are more complete than other Geiger counters I've seen on Amazon. Just be aware that the needle display is not useful unless you happen to be around something that's really radioactive. Also, Geiger counters cannot be returned to Amazon, so you might be stuck with it.I wish that Amazon gave information about the sensitivity of the GM tubes in each of their Geiger counter products. I would like to find a counter which registers, say, 50 CPM for normal background radiation, using a larger tube window.

### ⭐ Geiger tube failed 2 months out of warrenty.
*by B***R on October 24, 2014*

BEWARE OF QUALITY.Unit failed after 1 year and 2 months (just out of the one year warranty) and SE charged me full repair price ($150). It was a bad geiger tube. I had used it about 3 times (for about 5 minutes each time) over the course of the year. It was not subject to any environmental issues (I left it in the original box).

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*Product available on Desertcart Netherlands*
*Store origin: NL*
*Last updated: 2026-02-28*