Monitor 4

The Monitor 4 detects Alpha, Beta, Gamma, and X-radiations. It also offers 3 operating ranges, a battery check feature, and includes a padded carrying case (right) with belt clip.

A red count light flashes with rising radiation levels, along with an audible click which can be switched off for silent operation (see below right).

Radioactivity also registers on a dual scale analog meter adjustable for 3 operating ranges up to 50 mR/hr or 50,000 CPM (below left).

Play this sound file to hear the audible clicks of the Monitor 4, recording 3 different tones, depending on which of the 3 operating ranges is set.

In addition to detecting X, Gamma, and Beta radiation, the Monitor 4 is capable of detecting Alpha radiation by virtue of a thin mica window at the end of the Geiger-Mueller tube.  It is located strategically at the top of the instrument which, combined with the ergonomic enclosure design, makes aiming the unit at a specific source for Alpha detection that much easier.  See photo at left.

This unit also has a Data Output port to record counts on a computer or data logger, as shown in the picture at right.  Click on this link for more on the on data output, and the optional Software accessories.

The Monitor 4 runs on a single 9 volt alkaline battery (included) which will last up to three months on continuous use at background levels.

Select the navigation button above, or click here for detailed Specifications on the Monitor 4.

The Monitor 4 is an excellent all-around Pocket Geiger Counter.  The switchable operating range is an especially nice feature if you are dealing with low levels of radioactivity - you can set it to the most sensitive operating range so the meter is easier to read, i.e. the needle will "jump" that much farther for the same level of radioactivity.

For the same price, the Monitor 4 is also available in a dual-scale meter that reads in ?Sv/hr (in lieu of CPM), in addition to mR/hr (see picture).  Readouts in ?Sv/hr are more popular in Canada and overseas.  So please specify below which meter configuration you wish to order.

Purchase the Monitor 4 below, or if you want to build your own Monitor 4 from a Kit, or consider the specialized Monitor 4EC model, or purchase the Software accessory, select the navigation button above or click on these links