6
O
ONYX OPERATION MANUAL
5. How ONYX Works
The ONYX
uses a 2-‐inch(7.1cm)
Pancake
Geiger-‐Mueller
tube with a low-‐density mica window to detect ionizing
radiation. The Geiger tube generates a pulse of
electrical current each time radiation passes through
and causes ionization. Each pulse is electronically
detected and registers as a count. ONYX
displays this
collected data in the mode you choose: Counts Per
Minute (CPM), microSieverts per Hour (μSv/hr) or
microRoentgens per-‐hour (μR/hr).
The number of counts detected by ONYX
varies from
second to second, due to the random nature of
radioactivity, but averaging protocols provide a fairly
stable average of that random data
.
6. Applications of ONYX
If you work around radiation sources, ONYX
is a good instrument for personal health protection.
In normal environments, the instrument can
also provide peace of mind, by letting you know if there
are any unexpected radiation sources in your
environment. If you are documenting contamination or
collecting data for the Safecast Global Network or other
networks, you may share the data you collect.
