Patent ID: 7592603

Claim:
A portable radiation detector comprising: a radiation sensing system that includes a first measurement channel and a second measurement channel, wherein the first and second measurement channels measure the same radiation but the second measurement channel is less sensitive than the first measurement channel; a measurement unit coupled to the radiation sensing system, wherein the measurement unit uses a signal from one of the first and second measurement channels to determine a measurement of radiation, wherein the measurement unit comprises: a rate unit operably coupled to the first and second measurement channels, wherein the rate unit determines a radiation rate; and a dose unit operably coupled to the first and second measurement channels, wherein the dose unit determines a radiation dose received by a user transporting the detector; and a control unit that switches the measurement unit from using the first measurement channel to using the second measurement channel in response to a count rate from the first measurement channel indicating that the count rate from the first measurement channel is unreliable.