The system is composed of an Aer'ODE software, a spectrophotometer, a thickness gauge and an IBM Compatible PC. Aer'ODE software totally controls the spectrophotometer and the thickness gauge to ensure the automatic setting of these measuring devices (Absorbance mode, Wavelength, zero of absorbance and zero , unit for thickness ).

Calibration curve fitting

A set of irradiated dosimeters at known doses, is used in order to build the calibration curve (ASTM E1261). The software chooses automatically the best polynomial fit with the F-value (F-statistic) or r2 criteria according to ASTM E1707. Calibration parameters are directly stored under a data base to be available for routine dose measurements without any transcription error.

Routine Dose Measurement

The software proposes single (FWT, Harwell, Risö, CTA, ...) or continuous dose measurements (CTA, Risö, Sunna,...).

The serial interfaces directly capture the reading parameters of the dosimeters (Absorbance, thickness). The specific absorbance (OD/t) is calculated through the PC with a maximum uncertainty of 2,5 %. Based on the calibration curves previously built into the PC, a mathematical calculation links this parameter to the dose absorbed by the dosimeter. Each dose value is associated with an uncertainty evaluation according to ASTM E1707.

Electron Beam Energy Evaluation

This procedure is based on dose measurements with strip films like CTA, Risö B3, Sunna ... inserted in a wedge of material (Polyethylen, Polystyren, Aluminium).This option gives the depth dose distribution and based on the ASTM E1649, the following parameters : Rp, R50, E, Ea, Ep respectively, the half value depth, practical range, mono-energetic energy, average energy and most probable energy for energies between 1 and 10 MeV are calculated.

Instrument Check

The routine utilization in dosimetry laboratories contributes greatly to compliance with quality assurance requirements in any field relating to radiation processing. In this context, the software performs instrument checks (Absorbance, Wavelength, thickness and film length control) on a regular basis in order to prove the validity of the dose measurements.

Absorbance test screen	Wavelength test screen
Thickness gauge test screen

Data storage

Following the operator's instructions, the analysis results are stored into the data base. This type of storage gives rapid and reliable access to the data saved at each level of the control systems (calibration, dose measurements, instrument checks). A printer then issues the forms necessary for interpretation and storage of information. The files can be opened under Access or Excel.

Adaptations

It is important to note that the use of this device is characterized by a great flexibility. Moreover, Aérial can adapt the Aer'ODE software to the specific needs, requirements and readout instruments of the customer.

Efficiency - Reliability

The principle of the Aer'ODE system is a major contribution to the efficient control of dosimetry in an irradiation plant.
Being fully automatic PC controlled, the system is time saving and reduces quite significantly the risk of dosimeter reading errors. As the software runs under Window NT, 2K, XP systems, it is also possible to integrate it into the global control system of a radiation unit.

Quality Assurance

Finally, its routine utilization in dosimetry laboratories contributes greatly to compliance with quality safe requirements in any field related to radiation. In this context, quality assurance specifications are provided with each analysis system so as to carry out the specified tests on a regular basis and ensure its good working condition.
Being fully automatic PC controlled, this stand-alone or integrated system (link with irradiation plant network) is time saving, reduces quite significantly the risk of dosimeter reading errors and provides maximum benefit according to the quality assurance requirements   (EN 552, ISO 11137, ASTM E 1204, E 1431 ... ).