Geiger Counter (Fallout)

Geiger counter is a Wattz Electronics C-Radz model Geiger Counter. It detects the presence and strength of radiation fields.

Characteristics
Geiger counters make a familiar ticking sound when radiation is detected by it. The more radiation there is the faster and louder the ticking becomes. Useful for walking in areas with high amounts of radiation or swimming/wading irradiated waters which can both be lethal or hazardous to health. The Geiger counter has a limited amount of charges, which are depleted as it is turned on and off. The Geiger counter can also be used in one of your two slots to read your rad-count.

Fallout
One can be purchased in the Cathedral from the shopkeeper.

Fallout 2
One can be found in Vault City, in the lockers on the 3rd floor of Vault 8. The door is locked, so a lockpick is needed to access it. There is also a variety of valuable loot there, too. Another can be found on a bench in the basement of New Reno Arms.

Fallout 3 and Fallout: New Vegas
It is shown that the Pip-Boy 3000 models have a built-in Geiger counter.