Fluke Biomedical 07-649 - Manual (Page 10)

Nuclear Associates 07-649
Operators Manual
2-4
2.9 Time and mAs (Manual Mode Only)
If AEC is not used routinely for spot films, then record the following Manual mode technique values. If
time is pre-selected as part of the technique, then record it in the appropriate boxes. Time values are
recorded in milliseconds. Some units have pre-selected mAs; for these units, record the mAs value
selected and leave the mA and time blank. If the unit gives a post exposure digital readout of mAs, this
value should be recorded as mAs.
Spot or Photospot Technique Data with Barium Simulator (Copper)
Have the operator set up, at the console, the techniques routinely used for a spot or photospot film for the
upper GI examination of a standard patient with barium in the beam. Record the film copper kVp and film
copper mA selected.
If AEC is not used routinely for spot films, then record the following Manual mode technique values. If
time is pre-selected as part of the technique, then record it in the appropriate boxes. Time values are
recorded in milliseconds. Some units have pre-selected mAs; for these units record the mAs value
selected and leave the mA and time blank. If the unit gives a post exposure digital readout of mAs, this
value should be recorded as mAs.
Setup
Place the 1 mm sheet of copper on top of the phantom. Use an empty cassette for the barium spot film
measurements.
Set the x-ray unit for the four-on-one format. Without making any changes in the standard patient
techniques, with the phantom and probe properly positioned and the beam collimated to the four markings
on the phantom, take a spot or photospot film. Record the exposure as Film Copper Exposure #1.
Be sure that an empty cassette is in the spot film device: you are ready to make subsequent exposures.
Make an exposure, read and record the exposure measurement in mR as Film Copper Exposure #2
Time. Repeat this procedure, read and record Film Copper Exposure #3 and Copper Film #3 time.
2.10 Fluoroscopy HVL Data
Remove the copper from the top of the phantom. For the HVL measurement on all units, use the same
kVp used for the fluoroscopic upper GI examination.
HVL Manual Mode
The unit must be in the Manual mode with automatic brightness control (ABC) disabled for this method.
With the phantom and probe properly positioned, adjust the size of the fluoroscopic x-ray beam until it is
slightly larger than the sensitive volume of the probe head.
Set the probe selector switch to the Exposure Rate mode. Without making any changes in the standard
patient techniques, make an exposure of at least 15-second duration. Adjust the mA to obtain an
exposure rate of at least 1000 mR/min (1 R/min).
Record the kVp in the HVL section of the data form. Record the exposure rate in mR/min as exposure
rate for 0 mm of aluminum.
Place 1.5 mm aluminum on the tabletop directly beneath the sensitive volume of the probe and make a
second exposure of 15-seconds. Record the output in mR/min for 1.5 mm of aluminum.