Ion chamber trainer

A training instrument for use in teaching a trainee the proper use of a radioactivity measuring instrument includes a transmitter unit that is held and controlled by an instructor and further includes a receiver unit which is held and operated by the student and which simulates the radioactivity measuring instrument. The instructor selects a level of radioactivity to be measured by the student at a remote site, and that information is transmitted to the receiver unit in a moduated form that is not affected by atmospheric conditions or reflections from surrounding objects. Both the receiver and the transmitter include circuits that simulate the operation of a multirange meter. These circuits employ the most significant bits of a digital representation of the signal to determine which scale should be used, while the remaining digits indicate the magnitude of the signal as read on the selected scale. This technique permits the accurate simulation of both small and large levels of radioactivity over an exceptionally wide range of radioactivity levels.