Fluke Biomedical Victoreen NERO mAx 8000 User manual

Victoreen®8000
NERO® mAx
Users Manual
December 2006
Manual No. 8000-100-1 Rev. 9
©2006 Fluke Corporation, All rights reserved. Printed in U.S.A.
All product names are trademarks of their respective companies

Fluke Biomedical
Radiation Management Services
6045 Cochran Road
Cleveland, Ohio 44139
440.498.2564
www.flukebiomedical.com/rms

i
Table of Contents
Section 1: General Information................................................................................... 1-1
1.1 Product Description ..................................................................................... 1-1
1.2 New Features of Firmware 2.3..................................................................... 1-3
1.3 Specifications............................................................................................... 1-4
1.4 Battery Operation and Charging.................................................................. 1-5
1.5 Printing......................................................................................................... 1-6
1.6 Scope Output............................................................................................... 1-6
1.7 Procedures, Warnings, and Cautions .......................................................... 1-7
1.8 Receiving Inspection.................................................................................... 1-8
1.9 Storage........................................................................................................ 1-8
Section 2: Operation.................................................................................................... 2-1
2.1 Description................................................................................................... 2-1
2.2 General........................................................................................................ 2-1
2.3 Using the NERO mAx.................................................................................. 2-5
2.3.1 LCD Backlight Control............................................................................ 2-6
2.3.2 Measured Quantities .............................................................................. 2-7
2.4 Quick Start................................................................................................... 2-9
2.5 Modes of Operation ................................................................................... 2-10
2.5.1 Radio Mode.......................................................................................... 2-12
2.5.2 Mammo Mode ...................................................................................... 2-17
2.5.3 Fluoro Mode......................................................................................... 2-20
2.5.4 AMSE Mode......................................................................................... 2-25
2.5.5 CT Exposure Mode............................................................................... 2-28
2.5.6 Exp Mode............................................................................................. 2-30
2.5.7 HVL Mode ............................................................................................ 2-32
2.5.8 Cal Mode.............................................................................................. 2-43
2.5.9 Setup Mode.......................................................................................... 2-44
2.5.10 Unit ID .................................................................................................. 2-46
Section 3: Calibration.................................................................................................. 3-1
3.1 General........................................................................................................ 3-1
3.2 Calibration Check ........................................................................................ 3-1

ii
Section 4: Troubleshooting ........................................................................................ 4-1
4.1 General........................................................................................................ 4-1
4.2 Modes of Operation ..................................................................................... 4-2
4.2.1 Radio Mode............................................................................................ 4-2
4.2.2 Mammo Mode ........................................................................................ 4-5
4.2.3 Fluoro Mode ........................................................................................... 4-5
4.2.4 AMSE Mode........................................................................................... 4-6
4.2.5 Exposure Mode & CT Exposure Mode................................................... 4-6
4.2.6 HVL Mode .............................................................................................. 4-6
4.3 Error Messages ........................................................................................... 4-7
4.4 Power Up Diagnostic Messages................................................................ 4-11
4.5 Waveforms - Overshoot............................................................................. 4-12
4.6 Waveforms - Partial kV Waveforms........................................................... 4-14
4.7 Waveforms - Self Rectified ........................................................................ 4-16
4.8 Waveforms - Dental with Filament Preheat................................................ 4-16
Section 5: Maintenance............................................................................................... 5-1
5.1 Fuse Replacement....................................................................................... 5-1
5.2 Battery Replacement ................................................................................... 5-1
5.3 Routine Cleaning......................................................................................... 5-2
Appendix A: Temperature and Pressure .......................................................................A-1
A.1 Temperature and Pressure..........................................................................A-1
Appendix B: mA Limits vs. kV........................................................................................B-1
B.1 mA Limits vs. kV ..........................................................................................B-1
Appendix C: Exposure and Rate Resolution and Limits..............................................C-1
C.1 Exposure and Rate Resolution and Limits...................................................C-1
Appendix D: CT Exposure Resolution...........................................................................D-1
D.1 CT Exposure Resolution..............................................................................D-1
Appendix E: Ion Chamber of Sensitive Volume............................................................E-1
E.1 Ion Chamber of Sensitive Volume ...............................................................E-1
Appendix F: Replacement Parts .................................................................................... F-1
F.1 Replacement Parts......................................................................................F-1
F.2 Accessories .................................................................................................F-2

1
General Information
Product Description
1-1
Section 1
General Information
1.1 Product Description
NOTE
To proceed directly to "Quick Start", go to Section
2.4.
To proceed directly to "Setup Mode", go to Section
2.5.9.
The Victoreen NERO™ mAx Model 8000, Non-invasive Evaluator of Radiation Output, uses an
innovative system of menus and softkeys to provide an intuitive, user friendly operating environment. All
measurement modes and options are displayed on the NERO mAx’s LCD and all functions are controlled
by the 5 softkeys beneath the display and the 3 keys to the right of the display.
The NERO mAx consists of the NERO mAx control console, detector, detector cable, filter slides, AC
adapter, HVL plates, manual, Microsoft® Excel Add-in and carrying case.
The NERO mAx control console is compact and easy to use. The sophisticated electronics necessary to
provide highly accurate, reproducible measurements while maintaining an intuitive, user friendly operating
system are in the NERO mAx control console. The NERO mAx’s rechargeable battery is also housed in
the control console. The front panel of the control console contains a backlit 240 x 64 pixel, dot matrix
LCD display and eight push buttons. Connectors for power input, RS-232, printer, scope output and the
NERO mAx detector are located on the control console’s rear panel.

Victoreen 8000
Operators Manual
Figure 1-1.Control Console Front Panel
Figure 1-2. Control Console Rear Panel
1-2
The NERO mAx detector contains sensors for simultaneously measuring kV, exposure or rate and
invasive mA or mAs. Solid-state detectors are used to measure kV. An ion chamber, located in the top
of the detector, is used for exposure/rate measurements. In addition, connectors for an external ion
chamber are provided on the rear panel of the 8000 detector. The NERO mAx detector’s interface
connector is also located on the detector’s rear panel. The front panel has a keyed opening for the model
8000-filter slides and a connector for mAs leads.

1
General Information
Product Description
1-3
The NERO mAx filter cards contain the various filters needed to accurately measure kilovoltage. Each
filter card is coded so that the NERO mAx “knows” which filter is in use and its position. The NERO mAx
also verifies that the filter card is valid for the selected measurement mode. In addition, the filter cards
are keyed so that they may only be inserted one way. The W/Al filter card is labeled with the kVp ranges
for which it is calibrated. The Mammo filter card is labeled for the x-ray tube targets for which it is
calibrated.
The serial numbers of the NERO mAx control console unit, detector and filter cards must be matched in
order to obtain accurate results. Since the control console unit, detector and filter cards are calibrated
together, they must be used together for accurate measurements.
1.2 New Features of Firmware Release 2.3
This release adds several new features to the Radiographic mode that give the NERO mAx greater
flexibility when making kV and exposure time measurements on all types of radiographic and dental x-ray
machines.
1. The %kV setting provides more time measurement options:
• Time measurements from 90%, 80%, and 75% of the peak kV.
• Pulse counting and zero crossing settings for single-phase generator time measurements.
2. User settable measurement delay allows:
• kV overshoot portion of waveform to be excluded from kV analysis.
• Exclusion of x-ray generator preheat pulses from kV and time analysis.
More information on these new features may be found in “Using a Measurement Delay” and “Using %kV
and Exposure Time Measurements” at the end of Section 2.5.1--Radio Mode.

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1-4
1.3 Specifications
Kilovoltage
Measured during the first 480 ms of exposure
Accuracy: 0.5 kV or ± 1%
Reproducibility: 0.5 kV or ± 1%
Range: W/Al 30 - 60 kV
50 - 100 kV
80 - 160 kV
Mo/Mo 22 - 35 kV
Mo/Rh 22 - 40 kV
Mo/Al 22 - 49 kV
Rh/Rh 25 - 49 kV
Rh/Al 25 - 49 kV
Time To Display
Radio & Mammo: 3 seconds for 0.1 second exposure
1 second for each 32 ms of exposure time
Fluoro & AMSE: 15 seconds for all exposures
Time
Measured during entire exposure at 90% rise/fall of waveform.
Accuracy: 1 ms
Range: 1 ms to 60 sec
Exposure/Exposure & Rate
Measured during entire exposure; kVp corrected.
Accuracy: ± 5%
Reproducibility: (Radio & Mammo Modes) ± 2% or 2 mR
Range: 1 mR minimum
mAs and mA
Measured during entire exposure
Accuracy: ± 2%
Reproducibility: ± 1% or 0.2 mAs
Range: 1 - 1000 mA
HVL
Accuracy: ± 5%
Range: .1 - 99.9 mmAl
Physical
Display: 240 x 60 pixel, super twist LCD w/ccfl backlight
Power: 115 or 230 VAC External Supply. Rechargeable internal batteries supply more than
4 hours of continuous service with overnight charge.

General Information
Specifications
1
1-5
Size:
Console: 9.00" x 9.12" x 3.25" (22.86 mm x 23.17 mm x 8.26 mm)
Detector: 6.56" x 3.70" x 2.58" (16.66 mm x 9.4 mm x 6.55 mm)
Slides Only: 2.4" x 6.25" x 0.31" (6.1 mm x 15.88 x 0.8 mm)
Operating Conditions:
10° C to 40°C (50° F to 104° F)
Maximum 90% relative humidity (non-condensing)
Weight:
Console: 4 lbs. 9.0 oz. (2.067 kg)
Detector: 1 lb. 10.4 oz. (with slide) (.747 kg)
Slides Only: 2.9 oz. & 3.2 oz. (.090 kg & .094 kg)
HVL Set 2.30 mm, 1.0 mm, 0.3 mm
Calibration
W/Al calibrated with 4.5 millimeters of Aluminum total filtration
Mo/Mo calibrated with 30 microns of Molybdenum filtration
Mo/Rh calibrated with 25 microns of Rhodium filtration
Mo/Al calibrated with 1 millimeter of Aluminum filtration
Rh/Rh calibrated with 25 microns of Rhodium filtration
Rh/Al calibrated with 1 millimeter of Aluminum filtration
1.4 Battery Operation and Charging
The NERO mAx has an internal rechargeable battery which provides up to four hours of continuous
operation depending upon usage. The NERO mAx draws twice as much power from its from its battery
when it is actively making measurements than it does when in an idle state with its backlight off. To
conserve and extend battery life, the NERO mAx incorporates several power saving features. The
display backlight automatically turns off after one minute of inactivity. The backlight turns on when any
key is pressed or an exposure is made while in any measurement mode. In addition, the NERO mAx
exits from any measurement mode after five minutes of no activity. Pressing the ENTER key restores the
NERO mAx to its previous measurement mode.
The NERO mAx utilizes two levels of protection to assure reliable operation when the battery charge
becomes low. The first level of protection is a warning that is displayed when there is approximately 20
minutes of battery life remaining. During this time, the AC adapter may be plugged into the NERO mAx to
continue operation without interruption. The second level occurs when the battery charge is insufficient to
guarantee proper operation. When this occurs, the low battery indicator in the lower left corner of the
front panel illuminates and the instrument shuts down, becoming inoperable. When this happens, the AC
adapter can be plugged into the NERO mAx to restore operation. The NERO mAx “remembers” what
mode it was in before it shut down and returns to that mode upon power up. Pressing the ENTER key
returns the NERO mAx to its measurement mode.
The battery is charged whenever the NERO mAx is connected to its AC adapter and the adapter is
plugged into a suitable power source. When the power switch is on, the battery is charged at a low rate
that is enough to sustain the battery’s charge. When the power switch is off, the battery is charged at a
high rate.
To fully charge the battery, make sure that the NERO mAx is turned OFF, plug the AC adapter into the
rear of the NERO mAx console and plug the adapter into a suitable power source. The green battery

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Operators Manual
1-6
charge indicator on the front panel of the NERO mAx console illuminates when the battery is charging.
When the battery charge indicator is off, the battery is charged. It may take up to 16 hours to fully
recharge a severely discharged battery.
1.5 Printing
All of the exposure results displayed by the NERO mAx may be printed automatically if desired. The
data that is sent to the printer includes the NERO mAx’s mode of operation and selected options, the
current time and date, and the measured data. The NERO mAx uses a standard IBM compatible PC
printer cable.
With the NERO mAx turned off, plug the computer end of a standard IBM compatible PC printer cable into
the printer port at the rear of the NERO mAx then plug the printer end of the cable into the printer and turn
the printer on. Plug the AC adapter into the 8000 if needed (see Section 1.4--Battery Operation and
Charging) and turn the instrument on. From the readout menu, select setup screen and turn the
automatic printing on as follows:
SETUP CLOCK −> OFF
CAL PRINT −> ON
HVL UNITS −> R
EXP AIR −−− > 20.5 C 734 mmHg
CT EXP DATE −−> Oct. 10, 1996
AMSE TIME −−> 10 30 45
MODE SELECT ON/OFF
From the SETUP screen, use the SELECT softkey (under column 1) to select PRINT. When PRINT is
selected, the print selection blinks and a highlight (reverse video) extends across the other display field.
Press the ON/OFF softkey (under column 2) to turn automatic printing to ON. Now, whenever a
measurement is made, all of the measured results that are displayed on the NERO mAx’s screen will also
be sent to the printer.
If the printer is off line, out of paper or is otherwise non functional, the NERO mAx will display a printer
error message and printing will be disabled. If the printer becomes functional and returns to an on line
status with no errors, the NERO mAx will resume printing with the next exposure.
To turn automatic printing off, follow the procedure outlined above and toggle PRINT to OFF.
1.6 Scope Output
The NERO mAx scope output provides a real time output of the radiation waveform from the NERO mAx
detector. This output is from the less filtered detector; “channel A”. This signal can have a maximum
amplitude of approximately 5 volts. This signal is always available at the scope output BNC connector.
The NERO mAx does not need to be in a kVp measurement mode to provide a real time scope output,
but the NERO mAx detector must be in the beam.
To use the real time scope output, connect the NERO mAx’s scope output to an oscilloscope input using
a suitable BNC cable. Set the oscilloscope horizontal deflection controls to the desired sweep period and
adjust the scope to trigger on a positive slope. Some experimentation will be necessary to get the trigger
level and the vertical deflection adjusted properly. Generally, exposures made at the top of the selected
kV range will have signals above one volt and exposures made near the bottom of the selected kV range
will have signals in the tens of millivolts.

1
General Information
Procedures, Warnings, and Cautions
1-7
1.7 Procedures, Warnings, and Cautions
The equipment described in this manual is intended to be used for the detection and measurement of
ionizing radiation. It should be used only by persons who have been trained in the proper interpretation of
its readings and the appropriate safety procedures to be followed in the presence of radiation.
Although the equipment described in this manual is designed and manufactured in compliance with all
applicable safety standards, certain hazards are inherent in the use of electronic and radiometric
equipment.
WARNINGS and CAUTIONS are presented throughout this document to alert the user to potentially
hazardous situations. A WARNING is a precautionary message preceding an operation that has the
potential to cause personal injury or death. A CAUTION is a precautionary message preceding an
operation that has the potential to cause permanent damage to the equipment and/or loss of data.
Failure to comply with WARNINGS and CAUTIONS is at the user’s own risk and is sufficient cause to
terminate the warranty agreement between Fluke Biomedical and the customer.
Adequate warnings are included in this manual and on the product itself to cover hazards that may be
encountered in normal use and servicing of this equipment. No other procedures are warranted by Fluke
Biomedical. It shall be the owner’s or user’s responsibility to see to it that the procedures described here
are meticulously followed, and especially that WARNINGS and CAUTIONS are heeded. Failure on the
part of the owner or user in any way to follow the prescribed procedures shall absolve Fluke Biomedical
and its agents from any resulting liability.
Indicated battery and other operational tests must be performed prior to each use to assure that the
instrument is functioning properly. If applicable, failure to conduct periodic performance tests in
accordance with ANSI N323-1978 (R1983) Radiation Protection Instrumentation Test and
Calibration, paragraphs 4.6 and 5.4, and to keep records thereof in accordance with paragraph 4.5 of the
same standard, could result in erroneous readings or potential danger. ANSI N323-1978 becomes, by
this reference, a part of this operating procedure.
Warning Summary
The following WARNINGS are provided for your reference and may appear throughout the NERO mAx
manual: WARNING
Extreme caution should be used when making
connections to the mAs terminals of the X-ray
generator or detector. Improper connections may
result in injury, damage to the NERO mAx, and/or
damage to the x-ray generator. Tube current (mA
and mAs) measurements should only be made by
persons familiar with the calibration and repair of x-
ray machines.
WARNING
An electric shock hazard exists between the ion
chamber bias connector and ground.

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Operators Manual
1-8
Caution Summary
The following CAUTIONS are provided for your reference and may appear throughout the NERO mAx
manual:
NOTE
CAUTION
CAUTION
Use extreme caution when connecting to the mAs
terminal of the detector.
If line voltage surges beyond 15% of normal, a
power line conditioner must be used, otherwise
damage to the charging circuit will occur.
Note Summary
In the event of a transient induced lockup of the
Model 8000 NERO mAx, it is necessary to reset the
unit by cycling its power (turning it off then on).
After reset, the unit will power up in its normal
operating mode.
1.8 Receiving Inspection
Upon receipt of the package:
1. Inspect the carton(s) and contents for damage. If damage is evident, file a claim with the carrier
and notify Fluke Biomedical at 440.248.9300.
2. Remove the contents from the packing material.
3. Verify that all items listed on the packing list have been received and are in good order.
1.9 Storage
If the unit is to be stored prior to use, pack it in the original container, if possible, and store in an
environment free of corrosive materials, fluctuations in temperature and humidity, and vibration and
shock.
Prior to use, check the condition and functionality of the device. Also check that the calibration is still
valid. Periodic recalibrations are usually required by individual radiation safety and/or quality assurance
programs. Please consult your local radiation safety or quality assurance office if you have any
questions.

Operation
Description
2
2-1
Section 2
Operation
2.1 Description
The NERO mAx consists of the NERO mAx control console, detector, detector cable, filter slides, AC
adapter, HVL plates, manual, Microsoft Excel Add-in and carrying case.
The NERO mAx control console is compact and easy to use. The sophisticated electronics necessary to
provide highly accurate, reproducible measurements while maintaining an intuitive, user-friendly operating
system are contained in the NERO mAx control console. The NERO mAx’s rechargeable battery is also
housed in the control console. The front panel of the control console contains a backlit 240 x 64 pixel, dot
matrix LCD display and eight push buttons. Connectors for power input, RS-232, printer, scope output
and the NERO mAx detector are located on the control console’s rear panel. The ON/OFF switch is
located on the right side of the control console.
The NERO mAx detector contains sensors for simultaneously measuring kV, exposure or rate and
invasive mA or mAs. Solid-state detectors are used to measure kV. An ion chamber, located in the top
of the detector, is used for exposure/rate measurements. In addition, connectors for an external ion
chamber are provided on the rear panel of the 8000 detector. The NERO mAx detector’s interface
connector is also located on the detector’s rear panel. The front panel has a keyed opening for the model
8000-filter slides and a connector for mAs leads.
The NERO mAx filter cards contain the various filters needed to accurately measure kilovoltage. Each
filter card is coded so that the NERO mAx “knows” which filter is in use and its position. The NERO mAx
also verifies that the filter card is valid for the selected measurement mode. In addition, the filter cards
are keyed so that they may only be inserted one way. The W/Al filter card is labeled with the kVp ranges
that it is calibrated for. The Mammo filter card is labeled for the x-ray tube targets that it is calibrated for.
The serial numbers of the NERO mAx control console unit, detector and filter slides must be matched in
order to obtain accurate results. The control console unit, detector and filter slides are calibrated
together, and must be used together for accurate measurements.
2.2 General
Positioning the Control Console
Position the NERO mAx control console on a stable, flat surface within 25 feet of the detector. If a printer
is to be used with the NERO mAx it should also be placed on a stable, flat surface.
Positioning the Detector
Correct and reproducible positioning of the NERO mAx detector in the x-ray beam is very important in
obtaining accurate and reproducible results from the NERO mAx. Fluke Biomedical has printed several
alignment marks on top of the detector to assure correct, reproducible positioning of the detector.
The black circle is the minimum collimated beam size required for accurate exposure, rate and kVp
measurements. This circle defines the diameter of the NERO mAx’s internal ion chamber.

Victoreen 8000
Operators Manual
2-2
NOTE
The dashed gray rectangle is the minimum
collimated beam size required for accurate kVp
measurements only. This rectangle outlines the
NERO mAx’s kV detectors. Exposure and rate
results from an x-ray beam collimated to this area
will be incorrect because the beam is not
illuminating all of the internal ion chamber.
The black square and the dashed black crosshairs are alignment marks to aid in positioning the NERO
mAx detector in the x-ray beam.
The red arrows on the detector indicate the axis of the detector that should be aligned with the x-ray tube
axis for the most accurate measurements. This minimizes any heel effect.
Radiographic
Install the W/Al filter slide in the detector and set the filter slide to the desired kVp range. Position the
detector under the x-ray tube with the top of the detector facing up. Align the detector along the axis of
the x-ray tube to minimize heel effect. Set x-ray tube SDD (normally 26 inches) and collimate the beam
size to the round or square alignment marks on the top of the detector. Align the x-ray beam by making
the light field crosshairs coincident with the crosshairs on the top of the detector.
Dental
Set the detector on a flat, stable surface and position the x-ray tube so that the cone is just above the
detector's top surface.

2
Operation
General
2-3
NOTE
Do not rest the cone on the detector. This may
depress the top of the ion chamber and cause
incorrect exposure measurements.
Make sure that the detector is aligned along the axis of the x-ray tube and that the tube is perpendicular
to the detector's top surface and is centered over the detector crosshairs.
Mammography
Install the Mammo filter slide in the detector and set the filter slide for the x-ray machine’s target material.
Position the detector under the x-ray tube with the top of the detector facing up. Align the detector along
the axis of the x-ray tube to minimize heel effect. Set x-ray tube SSD (normally 26 inches) and collimate
the beam size to the square alignment marks on the top of the detector. Line up the front edge of the
square alignment mark on the top of the detector with the front edge (toward the chest wall) of the
collimated x-ray beam.
Fluoroscopy
Install the W/Al filter slide in the detector and set the filter slide to the desired kVp range. The kVp range
is the range closest to the detector front panel.
Position the detector upside down on the table (the top of the detector must be positioned toward the x-
ray tube) and align the detector along the axis of the x-ray tube to minimize heel effect. Using the
centering marks provided on the table (or other centering methods), center the detector over the x-ray
beam. Don protective clothing and energize the fluoroscope to view the detector on the fluoro screen.
Move the fluoroscope so that the lead shield containing the NERO mAx’s detector diodes (opaque
rectangle) is centered on the screen.
X-Ray Tube Axis
Fluoro Detector Positioning
Collimate to this area

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Operators Manual
2-4
For automatic brightness control machines, place appropriate shielding over the detector to drive the
output to its maximum. A folded lead apron, gloves or a lead sheet may be used. For manual systems,
set the machine for its maximum output and use appropriate shielding to protect the image intensifier.
Other Applications
The basic principles are the same for other applications. In general, the detector should be located 18 to
40 inches from the x-ray source. The detector should be aligned with the x-ray tube axis with the top of
the detector facing the x-ray source. The detector should be in the center of the x-ray beam and the
beam should be collimated to the round or square alignment marks on the top of the detector.
For chest x-ray machines, the detector may be strapped or taped to the table in front of the film cassette.
For panoramic dental machines, the detector may be strapped or taped to the film cassette holder.
Inserting the Filter Slide
The NERO mAx filter slides are inserted into the front of the detector. The filter slides are keyed so that
they may only be inserted one way. To insert the filter slide, place the filter slide in the opening in the
front of the detector and gently push. The slide will click into place at each of its positions. Move the filter
slide until the desired kVp range (W/Al) or target material (Mammo) is closest to the detector front panel
(below “kVp RANGE”).
Connections to the NERO mAx
The NERO mAx detector and control console are connected to each other via a 25-foot cable. The
NERO mAx power should be turned off when connecting the detector to the control console, connecting
an external ion chamber to the detector or connecting the mAs leads.
mAs Connections
WARNING
Extreme caution should be used when making
connections to the mAs terminals of the X-ray
generator. Improper connections may result in
injury, damage to the NERO mAx, and/or damage
to the x-ray generator. Tube current (mA and
mAs) measurements should only be made by
persons familiar with the calibration and repair of x-
ray machines.
Two mAs cables are provided with the NERO mAx; 12-ft. long mAs leads and 12-ft. long mAs extension
leads. The mAs leads are black, with a miniature phone plug at one end and alligator clips at the other
end, the mAs extension leads have clear insulation with two banana plugs at one end and alligator clips
at the other end. The miniature phone jack of the black mAs leads plugs into the mAs jack on the front
panel of the NERO mAx detector. The alligator clips may then be connected to the generator’s mAs
terminals. If the black mAs leads have insufficient length, the mAs extension leads may be used to
provide additional length. The mAs extension leads may be used in two ways; the extension lead banana
jacks may be plugged into the generator’s mAs terminals (if the generator has banana jacks) or the
extension leads may be reversed and the alligator clips can be clipped to the generator’s mAs terminals.
The opposite end of the mAs extension leads are to be connected to the alligator clips at the end of the
black mAs leads. When using the mAs extension leads, care should be used to make sure that the leads
are not shorted together when they are connected.

2
Operation
General
2-5
The mAs leads should always be connected in the ground return of the high voltage transformer.
Damage to the generator or the NERO mAx or inaccurate measurements may result if the mAs leads are
connected to any point other then the ground return of the x-ray tube current. Tube current
measurements should only be made on generators providing open and short circuit protection of the
metering circuit and where the circuit operates near ground potential. The polarity of the mAs input signal
is not important because a full wave bridge is used in the NERO mAx mAs input circuit.
Printer Connections
When using the NERO mAx with a printer, both the printer and the NERO mAx should be turned off prior
to connection. The NERO mAx uses a standard IBM PC printer cable. For more information on printing
with the NERO mAx, see Section 1.5--Printing.
AC Adapter
The AC adapter may be plugged into the NERO mAx at any time. For more information on using the AC
adapter with the NERO mAx, see Section 1.4--Battery Operation and Charging.
Scope Output
The NERO mAx’s scope output may be connected to a suitable oscilloscope at any time. For more
information regarding the real time scope output, see Section 1.6--Scope Output.
2.3 Using The NERO mAx
The NERO mAx uses an innovative system of menus and softkeys to provide an intuitive, user-friendly
operating environment. All measurement modes and options are displayed on the NERO mAx’s LCD and
all functions are controlled by the 5 softkeys beneath the display and the 3 keys to the right of the display.

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Operators Manual
2-6
The NERO mAx display is divided into 5 columns, each column corresponds to the push button (softkey)
directly beneath it. The left most column is the “MODE” column that is used to select the NERO mAx’s
operating mode. The remaining four columns (1 through 4) display various options for each mode.
A highlight (reverse video block) denotes the selected menu element in each column. A blinking highlight
(reverse video block) locates the “active” menu column and highlights the selected menu element in that
column.
Legends, which describe the function of each softkey, appear along the bottom of the display. These
legends are separated from the rest of the display by a horizontal line. The time and date may be
displayed in the upper right corner of the display.
There are eight push buttons on the front panel of the NERO mAx. The five buttons directly beneath the
display are “softkeys”, their functions change according to the NERO mAx’s mode of operation. These
softkeys are used to select the NERO mAx’s mode of operation and various options within each mode.
These softkeys are also used to increment numerical values such as time or date. The “MODE” softkey
has two functions. First, it may be used to select the NERO mAx’s operating mode. Second, it may be
used to exit from any active measurement mode.
The “UP” and “DOWN” keys to the right of the display are also used to select the NERO mAx’s mode of
operation and various options within each mode. The “UP” and “DOWN” buttons move the highlight up
and down within each selected column to select various options. When the “UP” button is pressed, the
highlight moves up one menu element and wraps around when it reaches the top of the column and
returns to the bottom. When the “DOWN” button is pressed, the highlight moves down one menu element
and wraps around when it reaches the bottom. If only two options are available, the highlight toggles
between the two selections. In the calibration and setup modes, the “UP” and “DOWN” buttons are used
to toggle between options or to increment and decrement numeric values.
The “ENTER” button to the right of the display is used to initiate data acquisition and measurement with
options that have been selected. It also is used to accept numeric data in situations requiring data entry.
Each of the NERO mAx’s operating modes has a menu. All available menu options for each mode are
displayed in columns 1 through 4 above each softkey. All menus are left justified. This means that
changes made in columns on the left (such as the MODE column) may affect the columns of options to
the right. Softkey legends appear along the bottom of the display and as the menu options change, the
softkey legends change. The left most menu column is the ‘mode’ column, which displays the available
operating modes. The legend above the “MODE” softkey never changes, as this key always selects the
mode of operation of the NERO mAx.
Pressing the softkey under any column (MODE, 1 - 4) moves the blinking highlight into that menu column,
thereby selecting that column, and moves the highlight up through the available options. The highlight
wraps around when it reaches the top of the column and returns to the bottom. If only two options are
available, the highlight toggles between the two selections. In the calibration and setup modes, some of
the softkeys are used to toggle between options or to increment numeric values.
To make a measurement with the NERO mAx, simply highlight the desired measurement mode and
options and press the enter button. For more information on a specific measurement mode, see the
manual section that applies to that mode or x-ray generator type.
All of the NERO mAx’s operating modes are described in "Modes of Operation", following "Quick Start".
2.3.1 LCD Backlight Control
As a power saving feature, the NERO mAx LCD backlight turns off after one minute of no activity. The
backlight turns back on when any button is pressed. When the NERO mAx backlight turns off while
exposure results are being displayed, the backlight may be restored without affecting the displayed
exposure results by pressing any key except the MODE key. Pressing the mode key exits from the active
measurement mode and returns to the menu screen, erasing all exposure data.

Operation
Using the NERO mAx
2
2-7
2.3.2 Measured Quantities
kV
The NERO mAx calculates kVp from the ratio between two differentially filtered detector channels (A&B).
When an x-ray exposure is made, the NERO mAx samples the two detector channels simultaneously at a
rate of 100,000 samples per second. The detector waveforms are digitized by a pair of 100 kHz 16 bit
A/D converters and stored in memory.
The NERO mAx has sufficient memory to store up to 480 milliseconds of waveform data. For
radiographic exposures that exceed 480 milliseconds in length, the NERO mAx stores the first 320
milliseconds of the waveform and the last 160 milliseconds. This method allows storage of both the rising
and falling edges of the x-ray waveform. In the fluoro and AMSE modes, the NERO mAx stores a 480-
millisecond sample of the x-ray waveform after the SAVE key is pressed.
A delay of up to 999 milliseconds may be used to delay the start of kV data acquisition in the Radio and
Mammo modes. This delay may be used to skip events that occur at the beginning of an exposure, such
as an overshoot or undershoot. When a delay is used, only the kV data acquisition is effected.
Exposure, mAs and time measurements are not delayed and are measured over the entire exposure.
After the exposure is complete, the NERO mAx searches the stored channel A and B waveforms for ratio
peaks, when a peak is found it is stored. These peaks are then averaged and the average kVp is
calculated. While the NERO mAx searches for ratio peaks, it also looks for the highest peak, when the
highest peak is found it is stored and peak kV is calculated. Effective kV is calculated from the ratio of the
integrated A and B waveforms which is analogous to the density ratio in the kVp film cassette.
When calculating kVp average in the radiographic mode, the NERO mAx only includes peaks that are
above the selected %kV in its kVp average calculation. When ZERO or 1ØPULSE are selected, the
NERO mAx includes all detected peaks in the kVp average calculation.
The NERO mAx calculates kV as a function (F) of the ratio between the two detector channels, A and B
(r). The calculations used to calculate kV peak, kV effective and kVp average are summarized below:
kVp Average = F (r), where r is the average peak ratio B/A
kV Peak = F (r), where r is the peak ratio B/A
kV Effective = F (r), where r is the ratio ∑B/A∑
The calibration information that the NERO mAx uses to calculate kV is stored in nonvolatile memory in the
NERO mAx control console.
Time
The NERO mAx measures exposure time by determining the time between the first and last passage
through a preset percentage of kVp average. To accomplish this, the NERO mAx calculates the detector
ratio that corresponds to the preset percentage of the exposure's kVp, then measures the time between
those points on the rising and falling edges of the ratio waveform. In the Radiographic mode, the
percentage of kVp average over which the NERO mAx measures radiographic exposure time may be
selected using the %kV key. In the Mammographic mode, the percentage is fixed at 90% of kVp
average.
In the radiographic mode, when 75%, 80%, or 90% kV is selected, the NERO mAx measures exposure
time between the 75%, 80%, or 90% points on the kV waveform. When zero crossing (ZERO) is
selected, the NERO mAx measures radiographic exposure time from the moment x-rays are detected
until they are no longer detected. When 1ØPULSE is selected, the NERO mAx counts the number of x-
ray pulses in a pulsed or single-phase radiographic exposure. This is primarily for use with single phase
full and half wave rectified generators.
In pulsed and single-phase applications when time is measured in pulses (1ØPULSE), use of a
measurement delay may introduce errors in the pulse count because the NERO mAx does not count
pulses during the delay time. In pulsed and single-phase applications when time is measured at a

Victoreen 8000
Operators Manual
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percentage of kV, use of a measurement delay can also introduce errors. If the delay terminates between
pulses, when no x-rays are present, the NERO mAx waits until the beginning of the next pulse to begin
timing. If the delay terminates during a pulse, when x-rays are present, the NERO mAx begins timing
immediately.
When a delay is used in making measurements in the Radio and Mammo Modes, the NERO mAx
calculates exposure time differently. If a positive measurement delay is used in making a measurement,
the NERO mAx includes the delay time in its calculated exposure time. In addition, the exposure time
may be slightly longer than the exposure time between the selected %kV points on the kV waveform.
This is because the Model 8000 does not store the leading edge of the x-ray output waveform; it waits for
the specified delay time before acquiring kVp data. Because of this, the %kV point on the rising edge of
the kV waveform is not stored and the rise time of the waveform appears to be instantaneous. The
difference between the actual and measured exposure times is the rise time between zero and the
specified %kV. When a negative measurement delay is specified, the NERO mAx does not include the
delay time in the measured exposure time. The measured exposure time is from the beginning of data
acquisition or the %kV point on the first rising edge after the delay until passage through the %kV point on
the falling edge of the kV waveform.
More information on using the %kV function or using a measurement delay may be found at the end of
the Radio Mode section under "Using %kV and Exposure Time Measurements" or "Using a Measurement
Delay".
Exposure and Exposure Rate
The NERO mAx measures exposure by integrating the signal from an ion chamber (either internal or
external) and applying the proper conversion factor(s) to calculate exposure (R or Gy). Exposure rate is
calculated by sampling the integrated charge from the ion chamber at one-second intervals and dividing
the integrated charge by the sample period and applying the proper conversion factor(s). In the Pulsed
Fluoro and AMSE modes, the NERO mAx calculates exposure per pulse or frame by sampling the
integrated charge from the ion chamber at one second intervals and dividing by the number of pulses or
frames that it counts in a one second interval and applying the proper conversion factor(s). The NERO
mAx's ion chamber is internally vented and all exposure and rate measurements are corrected for air
density based upon user entered temperature and pressure.
The NERO mAx’s internal ion chamber is factory calibrated to provide accurate exposure and rate
measurements over the entire kVp range of the NERO mAx. These exposure and rate measurements
are adjusted by applying energy dependent correction factors that are determined by comparison to
applicable N.I.S.T. techniques.
In addition to the factory calibration, a user entered multiplier is available for exposure and rate
measurements made with the NERO mAx’s internal ion chamber.
When using external ion chambers, exposure and rate are calculated using the user entered calibration
factor (R/nC or Gy/nC) for the selected chamber. When making measurements in the CT Exposure mode
with a CT chamber, user entered beam width is also used in calculating exposure and rate.
mAs and mA
The NERO mAx measures mAs by integrating the signal from the mAs input during an x-ray exposure.
To calculate mA, the integrated signal from the mAs input is sampled at one-second intervals and divided
by the sample period. In the Pulsed Fluoro and AMSE modes, the NERO mAx calculates mAs per pulse
or frame by sampling the integrated signal from the mAs input at one second intervals and dividing by the
number of pulses or frames that it counts in a one second interval. The mA(s) circuitry is factory
calibrated using a calibrated current source and is not user adjustable.
HVL
In the HVL mode, the NERO mAx calculates half value layer based upon a series of exposure or rate
measurements made with varying thicknesses of aluminum absorbers placed in the x-ray beam. The
exposure or rate measurements may be made using the NERO mAx’s internal ion chamber or an external