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GCA-01C Analog Geiger Counters

GCA-01 Ports

   Detects Beta, X-ray and Gamma Radiation


The GCA-01C Geiger Counter is a general purpose radiation detecting instrument. It's primary radiation indicators are an audio click and an LED blink each time a radioactive particle is detected. Detects: beta, x-rays and gamma radiation. A 3.5mm Digital Output port on the side provides a TTL logic pulse each time a radioactive particle is detected. This TTL output may be used to connected to various digital adapters: The Model GCA-01 has an internal Geiger-Mueller tube.


  • Detects: Beta, Gamma and X-Rays.
       Detector Sensitivity
          . Beta above 36 KeV
          . X-Ray and Gamma above 7 KeV
  • Digital Output Port - Compatible with Digital Meter Adapter DMAD
  • External Power Jack
  • Headphone Jack
  • GM Tube dimension are approximately .375" (3/8") diameter by 4" in length.
  • Case Dimensions app. 3.5" x 5.75" x 1.25"

Geiger Counter Technical Data

Countable Pulse Resolution & Range 1 Count Per Minute (CPM) - 5000 Counts Per Second (CPS)

Radiation Resolution: (Imperial).05 mR/hr
Radiation Range: (Imperial) Background Radiation* 18-22 uR/hr - 1000 mR/hr
Radiation Resolution: (Metric).0005 mSv/hr
Radiation Range: (Metric) Background Radiation* 0.18-0.22 uSv/hr - 10.0 mSv/hr

*Background Radiation in our location on average varies between 18-22 uR/hr Imperial (0.18-0.22 uSv/hr Metric). Your background radiation may be different due to your location and elevation on the planet. 

The GCA-01C series is sensitive enough to detect background radiation as well as NORM (Naturally Ocurring Radioactive Materials) and TENORM (Technologically Enhanced Naturally Occurring Radioactive Materials) objects in your enviroment.

GCA-01C Geiger Counter

Additional Options
AC Adapter  Add $12.95
Belt Clip  Add $10.00

Geiger Counter Accessories

This page lists many adapters and nuclear accessories we offer.

Optional Belt ClipBelt clip in use

Optional Belt Clip

Adapters for Analog Geiger Counters

Digital Meter Adapter -- Turns our analog into a accurate digital geiger counter

Geiger Graph Software - Turn your Geiger Counter Setup into a Radiation Monitoring Station

Spare External Wand

Natural Uranium -- radioactive source

Radioactive Sources -- CS-137, C0-60, Sr-90, Po-210

Analog Meter

Lead Sheets (1' x 1' x .032 thick )

USB to Serial Adapter