APPENDIX B. GLOSSARY page20
Model AM-255
B. GLOSSARY
ADC: Analog to Digital Converter, is an integrated circuit that converts an analog signal into a
binary number that can be used by the microprocessor.
CPS or cps: Counts Per Second
High Background Alarm/Fault: The condition that occurs if the counts exceed the
programmed high background level. This condition prevents further operation until the problem
is corrected. Normally set in cps.
LLD: The Lower Level Discriminator provides a threshold, usually adjustable, that determines
the lowest signal level that will be accepted as a nuclear pulse by the system’s electronics. Some
systems have both upper and lower level discriminators that can be used to set a discriminator
window. The discriminator window can be used to effectively reduce the background counts,
and increase system sensitivity to certain isotopes. Also see ULD.
Low Background Alarm/Fault: The condition that occurs if the counts fall below the
programmed high background level. This condition prevents further operation until the problem
is corrected. Normally set in cps.
POST: Power On Self Test
