Centronic
Centronic is a leading manufacturer of radiation detectors, gas-filled radiation detectors, silicon photodiodes, Geiger-Muller tubes, radiation tolerant cameras, coil wound components and UV instrumentation.
http://www.centronic.co.uk

Radiation Detection
Interesting experiments one can perform with homemade radiation detectors, and how to build them.
http://www.blackcatsystems.com/science/radiation.html

LND
Since 1964 LND, Inc. has been a leader in the design and manufacture of ionization chambers, Geiger tubes, x-ray proportional counters and neutron detectors.
http://www.lndinc.com/

Integrity Design and Research Co.
Integrity Design and Research Co. high quality instrumentation for ELF AC and DC measurement. Customers include Federal Government Agencies. NASA FDA US NAVY.. Magnetic Measurement Instrumentation.
http://www.gaussmeter.info/

RADRisk
Radiation and Environmental Protection Services
http://www.radrisk.com/

Landauer
Radiation dosimetry products and services to measure exposure to occupational and environmental radiation including X-ray, beta and gamma monitors, neutron badges, and radon gas detectors.
http://www.landauerinc.com

ORTEC
ORTEC is an industry leader in the design and manufacture of advanced high purity germanium and silicon detectors for gamma rays and charged particles respectively. The ORTEC brand name is synonymus with quality and innovation in nuclear instrumentation.
http://www.ortec-online.com/

International Radiation Detectors
International Radiation Detectors manufactures UV, XUV, and EUV photodiodes for applications in the vacuum ultraviolet, extreme ultraviolet and the soft x-ray spectral region and for detection of electrons. IRD also provides radiometric characterization.
http://www.ird-inc.com/

Radiation Safety Network
Home page for the Radiation Safety Network. The site is designed to assist radiation safety officers and radiation users in complying with radiation regulatory requirements.
http://www.radiationsafety.net/

Radrisk Consulting
Radiation and Environmental Protection Services. Nuclear and Electromagnetic Radiation.
http://www.radrisk.com/frontpage.htm