Radiation Monitoring
Handheld, Portables & Contamination

Tritium Monitor - Portable Model 400SBDyC

The Overhoff 400SDByC is a well established, high performance portable tritium in air survey meter. It offers excellent performance in sensitivity, stability, speed of response and gamma compensation and is particularly suited for low level monitoring in nuclear power stations and processing facilities.The 400 series has a variety of models depending upon application.


HTO discrimination is now possible with Model 400SBDγC-HTO. This is achieved by using a desiccant column resulting in measurement of HTO in the presence of other radioactive gases.

The 400 AC Model offers all features of the 400SDByC in addition to user ability to disable gamma compensation, inclusion of onboard rechargeable batteries and both manual and automatic calibration.



  • Sensitivity down to 74kBq/m3.
  • Effective gamma compensation, even in substantial non uniform gamma fields.
  • Rapid warm up takes place in less than 30 seconds and drift has been eliminated making manual zero adjustments unnecessary