The 7616 is a small but very sensitive end-window Geiger tube, able to respond to many types of ionizing radiation: Cosmic rays, X-rays, Gamma rays, Beta particles, and high-energy alpha particles. The 7616 G-M tube is QPL-qualified, meaning that it is capable of operating in the toughest military environment.

Size:
The 7616, being only 3/8ths inch diameter, and 2-1/2 inches long, makes it an ideal tube for a tiny probe, able to precisely locate a radiation source.

Use: Recommended operating voltage is nominally 760, with a working range of 710 to 950. Such a long 'plateau' makes this tube able to operate satisfactorily in a large variety of counters without modification or adjustment. as can the PRI 106B and C, 107B and C, the Hoffman Countmaster, All Detectron and RCA counters, etc.

Sensitivity: The 7616, having an end window, is considerably more sensitive to Beta particles than the 6993 commonly found in the CD V700 counters. The CD V-700 Civil Defense counter can be fitted with the 7616, making it capable of detecting low-energy beta, and high-energy alpha particles.

Radon: The daughters of Radon can then be detected with the CD V700, using a vacuum cleaner and paper towel "filter" to collect the daughters for about a minute. Placing the towel near the 7616's window will cause a rise in count proportional to the Radon concentration in the area.