MTR302/A - R302F/A - R302L/A DHHS
MANUALE ISTRUZIONI / INSTRUCTION MANUAL
Modello/Model R302/A
Calibration
1
R30
2/A
- Cali
bration
Ralco
srl
CALIBRATION
C
ENTERING
, X-
RAY
B
EAM
• Place a 35x43 cm. (14x17") cassette on the table top or other flat, horizontal surface.
• Position the x-ray tube/collimator assembly with the focal spot at 1 meter (40") over the
cassette with the x-ray beam perpendicular to the cassete surface. Do not use measure-
ment indicators on the system as reference values, but measure the distance from the
focal spot to the cassette surface.
If the x-ray beam cannot be positioned vertically use clamps, masking tape, or other material
as required, to position the x-ray tube and image receptor. The x-ray tube and the image
receptor must be set out at the specified FFD/SID distance perpendicularly to the x-ray tube as
described in the following procedure.
• Use the collimator light to centre the cassette in the field.
• Mark the location of the cassette with masking tape
or other means so that it may be removed and
replaced in the same position.
• Place white paper on top of the cassette to provide
maximum contrast for the light field.
• Set the collimator to provide a field size of 30x30 cm.
(14x14") at one meter (40").
• Activate the light field and use it to position 18 coins
as shown in the diagram.
• Position each pair of coins touching one another so
that the inner coin is lighted as much as possible and
the outer coin is lighted as little as possible.
• The points where the coins contact will define the
edges of the light field.
• The extra two coins are to be set:
• one in a corner to ascertain film position.
• the other at the instersection of the diagonals to define film centre.
• Set the x-ray generator to produce a density of about 50 kVp, 5 mAs.
• Make an exposure.
• Remove the cassette and process the film.
• Use the test film to check the alignments described below.
T
HE
FOLLOWING
PROCEDURES
REQUIRE
THAT
X
-
RADIATION
BE
PRODUCED
.
T
AKE
ADEQUATE
PRECAUTIONS
TO
MAKE
CERTAIN
THAT
NO
PART
OF
THE
HUMAN
BODY
IS
EXPOSED
TO
X
-
RADIATION
,
DIRECT
OR
INDIRECT
.
I
F
THE
DISTANCE
OF
1
M
FFD/SID
CANNOT
BE
DETERMINED
,
USE
THE
FFD (SID)
VALUE
CLOSEST
TO
ONE
METER
AND
CALCULATE
THE
MEASUREMENT
TOLERANCES
AS
THE
APPROPRIATE
PERCENTAGES
OF
THE
DISTANCE
.
Summary of Contents for R 302F/A
Page 4: ...MTR302 A R302F A R302L A DHHS Contents 2 ...
Page 77: ...info_cl fm ...