GE AMX-II User Manual

GENERAL ELECTRIC MEDICAL SYSTEMS AMX- X-RAY UNIT
7-1576 SM A0654E
5. Remove the cylinder by pressing the latch.
54 Large Field Size Check
1. Position a loaded 14” x 17” (35.5 cm x 43.2 cm) cassette under the collimator (17” (43.2 cm) dim-
ension transverse to the axis of the tube unit). Using the collimator measuring tape set the source-to-
image distance at 40“. (1.016 m).
2. Adjust the blades to yield a field size of 14“ x 17” (35.5 cm x 43.2 cm). Place a coin on the cassette
to identify the anode end of the x-ray tube.
CAUTION: THE FOLLOWING PROCEDURE REQUIRES THE PRODUCTION OF X-RAYS. OB-
SERVE RADIATION SAFETY RULES. A LEAD PROTECTIVE SCREEN, LEAD
APRON UNIT OR OTHER PROTECTIVE MEDIUM SHOULD BE USED TO AVOID
UNNECESSARY EXPOSURE. X-RAY REQUIREMENT INDICATED BY
3. Make a 50 KVP, 1 mas exposure and develop the film.
If cutoff in the transverse direction is observed, correct lead finger spacing should be verified. Refer to
Section 2-2. This should be done as follows:
4. Remove collimator lamp cable.
5. Remove the (5) 8-32 unc x 3/4” soc hms holding the collimator to the interface plate.
NOTE: Be careful not to loosen any of the 10-32 unf hex hms securing the interface plate to the
tube unit.
6. Place the collimator upright on a table (use soft material between the collimator and table top to
protect the finish). Fully close the transverse set of blades.
With this set of blades full closed, the lead finger spacing (measured at the top edge) should be between
5/32" (3.96 mm) and 3/16” (4.76 mm) and centered. If the spacing is greater, gently bend the fingers
toward each other until the gap is within this range. If the spacing is less, bend the fingers apart until the
gap is within these limits (preferably toward the 3/16” (4.76 mm) dimension). If the latter is done, visu-
ally check that the lower portion (heel) of each finger will not cause cutoff of the primary x-ray beam at
large field sizes.
Replace the collimator and make another exposure at the field size specified in Step 2. If cutoff is still
observed, alignment of the blade and/or shutter assemblies is faulty and the collimator must be replaced.
5-5 Field Lamp Voltage Check
The voltage at the collimator lamp socket must be at least 19.0 VAC RMS at a minimum battery voitage of
110 vdc. This is an indirect test of illumination level to meet HEW requirements.
Because the lamp voltage is a square rather than sine wave, the voltage measured with a Fluke 8000A Digital
Meter will be greater than the true RMS value. Lamp voltage can be measured with a True RMS caiculat-
ing digital meter such as a Weston/Schlumbuger, model 4445. Do not use an iron-vane AC voltmeter be-
cause it will load the lamp circuit.
1. o Remove the Blade Control knobs and collimator nameplate per Section 4.
2. Measure No Load Battery Voltage using a digital voltmeter.
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GE AMX-II Specifications

General

Brand	GE
Model	AMX-II
Category	Medical Equipment
Language	English