The Gamma Rate Meter (also known as Radiacmeter IM-179 Gamma Rate Meter) was used by Egon Spengler during the blasting of Chambermaid's cart in the Sedgewick Hotel and the battle of Gozer. Its use in the movie was never noted, but the device is.
While Ray Stantz suggested splitting up and searching the Sedgewick Hotel, Egon checked his Gamma Rate Meter. After Gozer seemingly vanished during the battle against the Ghostbusters, Egon checked his Gamma Rate Meter. He called out to Ray and stated, "This looks extraordinarily bad." An earthquake shook the roof and debris fell. Gozer's disembodied voice then demanded they choose its destructor form.
Real Life Uses
The Gamma Rate Meter reads radiation levels in the area.
- The meter wasn't made into a toy like the Ghost Sniffer.
- On page 16 of Ghostbusters Year One Issue #1, Egon uses the Gamma Rate Meter, the device he used before the disembodied voice of Gozer demanded them to chose a Destructor Form in Chapter 26: Gozer of the first movie.