Owner`s manual

Operator manual REX-***R(F)
LISTEM Corporation 36/90
3.5 AEC operation
3.5.1 Introduction
AEC makes regular strength of the film by controlling the exposed time.
It uses the Ionchamber as the sensor to measure the amount of X-ray. And if the amount of
incident X-ray come to the set radiation amount, the exposure is stopped.
3.5.2 Minimum response time & maximum exposure time
MRT is the minimum time to operate the system and MET is long exposure time as possible to
finish a irradiation.
Even though you set the exposure time very shortly, the AEC function of the REX-RF Series
doesn't make the excessive strength pictures regardless of MRT. And you can protect a patient
from the excessive exposure, even though there is any problem in AEC equipment, as the MET is
designed not to excess 600mAs per irradiation.
3.5.3 Intensifying screen & Film selection
It is necessary to control AEC system according to the collation of Film/Screen.
REX-RF Series is controlled on the strength with the standard of the rare earth type intensifying
screen/ortho type, and it should be set the strength compensation value of AEC differently
according to the intensifying screen and used film. This process should be carried out in the
factory, and it can be controlled suitably by the customer's ask.
3.5.4 Suggestions for using AEC
- Adjust perfectly pose of a patient to central beam.
- Use the AEC only when you use the grid.
- It is basic to select the suitable sensor in taking a X-ray with AEC.
- Adjust the terminal of strength control to “0” for the normal patients, and control the terminal only
for the extremely different figures or pathological situation.
- Therefore, don't often control the terminal of strength control.
- Select the central sensor for taking all of the skulls.
You may get a faint or dark picture when you use AEC, as follows;
-
When you take a lumbar you may get such picture, if the inner gas covers
the part of the field selection accidentally.
-
If the part which has abnormality in the absorption by region covers the
position of the sensor, you may get such picture.
- If the dye covers the position of the sensor, you may get such picture.
To adjust the proper strength by using AEC, you should adequately select the Positioning and
Field Selection