Specifications

E. CALCULATIONS
2.5 = X
S X + 13.95
2.5X + (2.5) 13.95 = XS
(2.5) 13.95 = XS - 2.5X
34.875 = X (S - 2.5)
X = 34.875
S - 2.5
The misalignments are calculated as follows:
Length misalignment = L
1
+ L
2
≤ 2% SID
Width misalignment = W
1
+ W2 ≤ 2% SID
Calculate 2% of the measured SID. Each of the misalignments, length or width,
must be less than or equal to 2% of the measured SID for compliance.
NEMA Standards 5-15-79
.03 METHOD III - ALTERNATE TEST STAND METHOD
A. GENERAL
1. The image of the radiation field on the film must be of uniform density
with sharply defined edges.
2. The graduated template is utilized to minimize the amount of error
introduced into the measurement of the X-Ray field size.
3. The actual versus indicated SID must be determined prior to performing
this test.
B. EQUIPMENT
1. Manufacturer’s recommended test stand.
2. Cassettes and film.
3. Graduated template.
November 2005 ( 5 - 13) Linear MC150-C Collimator