ACR Electronics L-32 FIELD MARKER LIGHTING SYSTEM Technical Information PDF herunterladen (Seite 39)

assembly.

When the maximum

is measured, the

entrance exposure of a unit

lead plate

protects the

intensifier from excessive

image

entrance

exposure

rates.

Also, it is good practice to avoid long exposures at the

maximum factors minimizing the chance of exceeding the

thermal rating of the x-ray tube.

These measurements

should be completed at

least

annually or

after

replacement of the x-ray tube, generator recalibration,

filter thickness change or adjustment to the AERC.

II-7-D. Qualitative Evaluation of Automatic Exposure late

Control Devices

Normally, one

should ensure

that the

automatic

exposure rate control device is functioning at least

annually or after repairs.

is a simple qualitative

The procedure described below

check. It

should

not be

considered a substitute for the quantitative

check which

should be completed

during

the original acceptance

testing of the automatic exposure rate control device and

subsequent calibrations.

In general,

the fluoroscopic

system's AERC should

select the fluoroscopic techniques listed in Table IV.

The various design strategies of accomplishing this are

discussed in Reference # 14.

These suggested technique

factor combinations are only rough guidelines, Equipment

and

selections in practice depend on the gain of

the image intensifier,

AERC sensor f-stop, the SID, the

FOV, and the AERC sensor gain adjustment and reference

voltage settings.

Thus, generally one should not pass

judgement on the AERC function unless the operational

logic of the AERC is understood.

1 2 ... 34 35 36 37 38 39 40 41 42 43 44 ... 60 61

Kommentare zu diesen Handbüchern

Keine Kommentare

ACR Electronics L-32 FIELD MARKER LIGHTING SYSTEM Technical Information Seite 39

Kommentare zu diesen Handbüchern