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SKU: 610708893868

Product Description

The CRM-100™ is a general purpose geiger counter that measures alpha, beta, gamma, and X-radiation. It is intended for personal safety and educational purposes. Like the popular Radalert® 100X, the CRM-100™ features a 3-second update on its digital liquid crystal display (LCD). The LCD shows the current radiation level in your choice of milliroentgens per hour from .001 to 110 or counts per minute (CPM) from 0 to 350,000. When SI units are selected, the LCD shows readings in microsieverts per hour from .01 to 1100 or counts per second (CPS) from 0 to 3,500. This instrument also offers an accumulated total and timer function, up to 9,999,000 counts and 40 hours. A red LED blinks and a beeper chirps with each count (the chirp can be muted).




  • Halogen-quenched Geiger-Mueller detector (LND712)
  • Mica end window density is 1.5-2.0 mg/cm²
  • Side wall is 0.012″ #446 stainless steel
  • Detects Alpha, Beta, Gamma, and X-radiation

Display: 4-digit liquid crystal display with mode indicators

Accuracy: ±10% typical; ±15% max. (mR/hr and µSv/hr modes)

Alert: No Alert feature. If your intended application requires a user-adjustable Alert, we recommend the Radalert® 100X

Audio: Beeper chirps for each count (can be muted)

Calibration: Cesium 137 (gamma)

Certifications: CE Certified, RoHS Compliant, and Meets WEEE standards

Count Light: Red LED flashes with each count

Designed & Manufactured: Designed in USA by IMI International Medcom, Inc. Manufactured in Thailand under ISO 9001:2001 & ISO 14001 Certification

Operating Range:

mR/hr: .001-110 CPM: 0-350,000
µSv/hr: .01-1,100 CPS: 0-3,500
Total: 0-9,999,000 counts Timer: up to 40 hours

Options: Computer cable and software


    • Output: Stereo 3.5 mm jack sends counts to computers, data loggers, other CMOS-compatible devices, and headphones
    • Input: Mono 2.5 mm jack provides electronic calibration input

Power: One 9-volt alkaline battery; average battery life is 2,160 hours at normal background, 625 hours at 1 mR/hr with beeper off

Sensitivity: 1000 cpm/mR/hr referenced to Cs-137

Size: 150 x 80 x 30 mm (5.9″ x 3.2″ x 1.2″)

Weight: 225 grams (8 oz) including battery


This product is warranted to the original owner to be free from
defects in materials and workmanship for two years from the
date of purchase with the exception of the Geiger-Mueller tube,
which is warranted for one year. The battery is not included
in this warranty. International Medcom, Inc. will, at its own
discretion, repair or replace this instrument if it fails to operate
properly within this warranty period provided that it has not
been subjected to misuse, abuse, or neglect. Modification or
repair of this instrument by anyone other than International
Medcom, Inc. voids this warranty.

Contamination of this instrument with radioactive materials
voids this warranty. Contaminated instruments will not be
accepted for servicing at our repair facility.

The user is responsible for determining the suitability of this
product for the intended application. The user assumes all risk
and liability connected with such use. International Medcom,
Inc. is not responsible for incidental or consequential damages
arising from the use of this instrument.

The terms of this warranty are subject to change without notice.