MTR221/A - MTR221/A DHHS
MANUALE ISTRUZIONI / INSTRUCTION MANUAL
Modello/Model R221/A - R221/A DHHS
C
ALIBRATION
19
R22
1/A
- R221
/A DHHS -
C
alib
ration
Ralco
srl
CALIBRATION
C
ENTERING
X-
RAY
B
EAM
WITH
C
OLLIMATOR
L
IGHT
• Place a 35 x 43 cm. (14 x 17") 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 cassette surface. Do not use
measurement indicators on the system as reference values, but measure the distance from
the focal spot to the cassette surface with a tape measure of similar device.
• Use the collimator light to center 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 30 x 30
cm. (12” x 12") at 1 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 intersection of the diagonals to define film center.
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
SID
CANNOT
BE
DETERMINED
,
USE
THE
SID
VALUE
CLOSEST
TO
ONE
METER
AND
CALCULATE
THE
MEASUREMENT
TOLERANCES
AS
THE
APPROPRIATE
PERCENTAGES
OF
THE
DISTANCE
.
I
F
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
.
T
HE
X-
RAY
TUBE
AND
THE
IMAGE
RECEPTOR
MUST
BE
SET
OUT
AT
THE
SPECIFIED
SID
DISTANCE
PERPENDICULARLY
TO
THE
X-
RAY
TUBE
AS
DESCRIBED
IN
THE
FOLLOWING
PROCEDURE
.
Summary of Contents for MTR 221/A
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