All dates issued by ORAU have an OxA number. There are different series of numbers corresponding to different levels of service and QA. Samples which have recieved the
full treatment are issued a unique OxA number [nnnn]. Others are identified by
their wheel number [www] and the position in that wheel [pp]. In the case
of measurements made with standards provided by other laboratories the wheel numbers are
is a different series [xxx].
- OxA-nnnn [Full treatment and QA; standard procedures]
- OxA-C-xxx-pp [AMS measurement; external standards]
- OxA-V-www-pp [Combustion; d13C; AMS measurement; external chemistry]
- OxA-W-www-pp [AMS measurement; ORAU standards]
- OxA-X-www-pp [Research measurement using non-standard techniques]
Samples given this type of number are subject to the full QA treatment at
all stages:
- sampling
- chemical pre-treatment
- combustion
- stable isotope and CN measurement
- AMS measurement
- archaeological interpretation
These dates are ususally published in ORAU datelists in Archaeometry.
Samples given this number are measured for outside laboratories. The standards and known
age material is supplied by those laboratories and they perform all of the QA. ORAU only
performs QA test on the:
- AMS measurement (internal consistency of external standards)
Samples given this number are made on material pretreated in other laboratories. Only the d13C
is measured in order to correct for fractionation. The results issued directly by the AMS
operators and are not subject to archaeological or stable istotope scrutiny. QA is performed
on:
- combustion
- AMS measurement
Samples given this number are made on material pretreated and combusted in other laboratories.
The results issued directly by the AMS
operators and are not subject to archaeological or stable istotope scrutiny. QA is performed
on:
- AMS measurement (ORAU standards are used)
These samples are research measurments using non-standard or
experimental methods.
QAP 15/03 Issue 1 29/09/99