Fluke Biomedical 8000 Victoreen - Manual (Page 64)

Victoreen 8000
Operators Manual
4-2
For more information on using NERO mAx with the Excel Add-in, please see the NERO mAx Toolkit for
Excel Instruction Manual.
NERO mAx does not respond
If the NERO mAx does not respond to depression of any of its keys it may be “locked-up” (its
microprocessor is no longer be executing its program properly). When this occurs, it is necessary to reset
the unit by cycling its power (turning it off then on). After reset, the unit will return to its normal operating
mode.
The NERO mAx may also appear to be locked up if one of its buttons is stuck in the depressed position.
If the button beneath a menu function is stuck, the reverse video highlight for that function will be
continuously cycling through the menu selections. If the button beneath a numeric value (time, date, etc.)
is stuck, that value will continuously increment. If the button with no menu function is stuck, there is no
indication on the display and the NERO mAx will not respond to any keypress. To determine if this is the
problem, simply depress each key. If a key does not depress, it may be stuck down and needs to be lifted
up. If a key’s function cannot be restored, repairs may be needed. Please contact Fluke Biomedical at
440248.9300 for assistance.
NERO mAx LCD goes blank or slows down during printing
When the NERO mAx is used with older, slower printers which have relatively small print buffers, the
printer may slow the NERO mAx down. The NERO mAx continuously monitors the status of the printer
during the printing process. When the printer’s print buffer fills and it cannot accept any more data, the
NERO mAx stops sending characters and waits until the printer can accept more data before continuing.
This prevents existing x-ray exposure data from being overwritten by new exposure data so that no
exposure data is lost. Wait until the printer stops printing, then continue.
4.2 Modes of Operation
4.2.1 Radio Mode
For an explanation of error messages, see Section 4.3--Error Messages.
The NERO mAx still says “MAKE EXPOSURE” after an exposure has been made
This happens when the x-ray beam intensity is below the NERO mAx’s detectability limit. To overcome
this, switch to high sensitivity, switch to the next lower kV filter range (if the kV is still within range) or
decrease the distance between the detector and the x-ray tube. See Appendix B, mA limits vs. kV, for
assistance in establishing the correct sensitivity for the chosen mA and kV.
If the NERO mAx still does not respond to exposures that are within the limits in Appendix B, mA limits vs.
kV, it may be in need of repair. Please call Fluke Biomedical at 440248.9300 for assistance.
Measured kV is not what is expected
If the measured kVp appears to be high, there may be an overshoot at the beginning of the exposure. To
eliminate this possibility, delay the start of data acquisition by 10 milliseconds (see Radio Mode). The
NERO mAx Excel Add-In may be used to extract the kV and radiation waveforms from the NERO mAx for
examination. See Section 4.5--Waveforms - Overshoot.
The amount and type of filtration in the x-ray beam also effects measured kVp. The filtration that the
NERO mAx is calibrated with is printed on the NERO mAx calibration report.
Incorrect kVp measurements will also result if the NERO mAx detector is not aligned properly in the x-ray
beam. The NERO mAx detector should be aligned along the axis of the x-ray tube, located in the center
of the beam with the top of the detector facing the tube. The x-ray beam should be collimated to the
alignment marks on the top of the detector. See section "Positioning the Detector" for more information.