Fluke Biomedical 8000 Victoreen - Manual (Page 51)

Operation
Modes of Operation
2
2-39
5.1
R/min
HVL INTERN RATE LOW
MODE CHAMBER MODE SENS SAVE
After the second exposure has started, the NERO mAx displays the exposure rate. When the rate has
stabilized or the desired rate has been achieved, press the SAVE softkey (softkey 4) to save the rate
measurement.
5.1
R/min
HVL INTERN RATE LOW TURN OFF
MODE CHAMBER MODE SENS BEAM
Turn off the x-ray beam. The NERO mAx has stored the measured exposure rate and will set up for the
next exposure as soon as the beam turns off.
5.1
R/min
ENTER THICKNESS: 3.30 mmAl EXPOSURE # 02
HVL
MODE THICKNESS REJECT
While the exposure rate from the second exposure is displayed, the user is prompted to enter the
thickness of the aluminum filter. To enter the filter thickness, press the THICKNESS softkey to
increment the filter thickness or use the UP and DOWN keys to increment and decrement the filter
thickness. When the correct filter thickness is displayed, press the ENTER key. If a filter thickness is
repeated, the NERO mAx will ask for confirmation that the latest exposure data is to be accepted.
Pressing the enter key accepts the HVL exposure data after the absorber thickness has been entered.
Pressing the reject key rejects the exposure data and the user is prompted to make the exposure over.
5.1
R/min
HVL 3.50
mmAl
Please Wait…
HVL INTERN RATE LOW
MODE CHAMBER MODE SENS
The HVL is calculated and displayed after the new exposure data has been entered and a “Please wait…”
message is displayed while the NERO mAx prepares for the next exposure. If the NERO mAx displays
“LOW” above the calculated HVL, the average of the added filtration is more than 10% less than the
calculated HVL and more aluminum filtration is needed. If the NERO mAx displays “HIGH” above the
calculated HVL, the added filtration is more than 10% above the calculated HVL and some of the
aluminum filtration should be removed. When more than two exposures have been made, the NERO
mAx checks the HVL data for goodness of fit by calculating its correlation coefficient (“r”), if the fit is poor
(r< 0.98), the “r” value will flash.