Thermo Scientific ASP2e Survey Meter

The ASP-2e/NRD is a portable, battery operated counter designed for the measurement of dose equivalent rate from neutrons (Rem). The detector employed is a 9 inch diameter, cadmium loaded polyethylene sphere with a BF3 tube in the center. This detector has been shown to have a response which closely follows theoretical dose equivalent from neutrons over the energy range from 0.0025 eV (thermal) to about 10 MeV. The BF3 tube additionally provides excellent gamma rejection. The accompanying counting instrument is the Model ASP-2e. This design combines the best features from conventional analog counters and marries them with state-of-the-art digital technologies to present the user with a very capable and user-friendly instrument. A dual analog/digital display facilitates the measurement process by presenting informative data in an optimum format. While the traditional analog meter scale presents relative scale and movement of the counts received, the digital display forwards exact count rate readout together with the units employed, the counting interval or elapsed time (depending upon the operating mode selected) along with other key operational parameters such as response time selected, alarm setpoints, high voltage, battery level, etc. Microcomputer-based, the ASP-2e/NRD corrects for coincidence loss so that the upper limit range of the detector is increased by a factor of ten or more. When the useful range is exceeded, an over-range alarm is given. The instrument has a built-in speaker, serial port for PC setup and calibration, and an easy access external battery compartment to facilitate battery replacement.