Users Manual Part 2

Clinical User’s Guide IBA | 15-5|
Volume 1 - Treatment Session
|Part II - Using Treatment Room Equipment Resetting a Dose Counter Electronic Unit |
Figure 15-2. Dose Counter Electronic Unit (DCEU) - detail
x10 Preset Value
Effects of Temperature and/or Pressure
Changes in the Treatment Room
Fluctuations in temperature and/or pressure have an impact on beam measurement
performed by Ionization Chamber 2/3 (IC2/3), which are located in the nozzle. The
impact is irrespective of the type of ionization chamber, be it sealed or open air
1
.
To ensure correct IC2/3 measurement, the ambient treatment room temperature and
pressure are measured and recorded every morning.
If, in the course of the day, temperature and/or pressure is observed to be deviating
from the values measured in the morning, these new values must be recorded using
the Dosimetry Manager. For detailed information on the Dosimetry Manager, refer to
Appendix A, Using the Dosimetry Manager.
preset display
Reset button
1. IC measurement is proportional to ambient temperature and pressure. A variation
in temperature of 1 °C or a variation in atmospheric pressure of 3 hPa from the
values registered in the Dosimetry Manager implies approximatively an error of
0.3%.