Preva Dental X-ray System
User Manual
Effective: May 2018
00-02-1576 Rev. X01
Preva Dental X-ray System — User Manual
Preva Dental X-ray System
User Manual
Lincolnshire, Illinois 60069 USA
Phone: 800-MIDMARK 800-643-6275
© Midmark Corporation 2018, U.S. Patents D470237, D469182, D470589, and 6,837,468
Midmark Corporation
675 Heathrow Dr.
Fax: (847) 415-9801
midmark.com
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Preva Dental X-ray System — User Manual
Table of Contents
GENERAL INFORMATION .......................................................................................................................... 4
INTENDED USE ............................................................................................................................................. 4
WARNINGS / PRECAUTIONS ........................................................................................................................... 5
X-RAY PROTECTION ..................................................................................................................................... 6
PRODUCT DESCRIPTION ................................................................................................................................ 6
CERTIFIED COMPONENTS .............................................................................................................................. 8
AUTHORIZED REPRESENTATIVES .................................................................................................................... 8
EXPLANATION OF SYMBOLS ON TECHNICAL LABELS ........................................................................................ 9
COMPLIANCE WITH APPLICABLE
OBTAINING TECHNICAL SUPPORT ................................................................................................................ 13
OPERATING INSTRUCTIONS ................................................................................................................... 14
USING THE OPERATOR PANEL ..................................................................................................................... 14
TAKING AN X-RAY ....................................................................................................................................... 16
ABOUT THE 20CM CONE (30-A2195) AND THE 30 CM CONE (30-A2200) ....................................................... 17
RECOMMENDED MAINTENANCE ........................................................................................................... 18
REGULAR MAINTENANCE............................................................................................................................. 18
CLEANING AND DISINFECTING ...................................................................................................................... 18
S
TANDARDS
............................................................................................ 10
CHECKING SYSTEM FUNCTIONS ........................................................................................................... 19
SYSTEM FUNCTION CHECKLIST ................................................................................................................... 20
NEW TUBE SEASONING PROCEDURE ............................................................................................................ 21
SOLVING PERFORMANCE ISSUES ......................................................................................................... 22
PERFORMANCE ISSUES ............................................................................................................................... 22
OBTAINING TECHNICAL SUPPORT ................................................................................................................ 22
SYSTEM CONFIGURATION ...................................................................................................................... 23
PREPROGRAMMED EXPOSURE TIMES ........................................................................................................... 23
CHANGING LANGUAGE ................................................................................................................................ 24
SYSTEM CONFIGURATION MODE .................................................................................................................. 25
ADJUSTING THE DISPLAY ............................................................................................................................ 26
CHANGING PREPROGRAMMED EXPOSURE SETTINGS ..................................................................................... 27
RECORD YOUR EXPOSURE SETTINGS (8” [20 CM] CONE) ............................................................................... 29
RECORD YOUR EXPOSURE SETTINGS (12” [30 CM] CONE) ............................................................................. 30
SHOWING CURRENT SYSTEM CONFIGURATION ............................................................................................. 31
CHANGING THE CONE SIZE ......................................................................................................................... 32
DIAGNOSTIC MODE ..................................................................................................................................... 33
SPECIFICATIONS ...................................................................................................................................... 34
PREVA DENTAL X-RAY SYSTEM ................................................................................................................... 34
STATEMENTS AND INFORMATION ACCORDING TO 21 CFR SUB CHAPTER J ..................................................... 35
THERMAL CHARACTERISTICS CHARTS .......................................................................................................... 36
STATEMENTS AND INFORMATION ACCORDING TO CANADIAN RADIATION EMITTING DEVICES REGULATIONS, PART II
SCHEDULE II ......................................................................................................................................... 37
OF
DOSE INFORMATION ................................................................................................................................... 39
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Preva Dental X-ray System — User Manual
General Information
Intended Use
The intended use of the Preva Dental X-Ray System is to act as a diagnostic source for
radiographic dental imaging.
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Preva Dental X-ray System — User Manual
Warnings / Precautions
Radiation Safety
•
radiation.
To avoid the risk of electric shock, this equipment
•
USB connector on the
Before cleaning or disinfecting, this equipment must always be
ray System is ordinary type medical equipment
leak inside the equipment.
Explosion Safety
This equipment must not be used in the presence of flammable or
vapor must be allowed to disperse before using the equipment.
Only qualified and authorized personnel may operate this equipment
observing all laws and regulations concerning radiation protection.
• The operator at all times must remain at a safe distance from the focal
spot and the X-ray beam for operator protection.
• Full use must be made of all radiation safety features on the equipment.
• Full use must be made of all radiation protection devices, accessories
and procedures available to protect the patient and operator from X-ray
Electrical Safety
WARNING:
must only be connected to supply mains with protective earth.
Because the design of the Preva power supply circuit may momentarily
draw high current, do not use this device with any wall outlet that has
a GFCI (Ground Fault Circuit Indicator). Outlets with GFCI breakers
are designed to trip when they sense a small amount of current passing
from the line to earth ground. Outlets with GFCI could compromise the
operation of the intra-oral X-ray device and the GFCI circuit itself.
• Only qualified and authorized service personnel should remove covers
on the equipment.
• All maintenance that requires removing of protective covers must be
executed by service personnel when the patient is not present.
• The sensor shall only be replaced when the operator and any part of the
machine does not touch the patient.
CAUTION: Operator is not to touch the
Articulated Arm.
• This equipment must only be used in rooms or areas that comply with all
applicable laws and recommendations concerning electrical safety in
rooms used for medical purposes, e.g., IEC, US National Electrical code,
or VDE standards concerning provisions of an additional protective earth
(ground) terminal for power supply connection.
•
disconnected from the main electrical supply.
• The Preva Dental X-
without protection against ingress of liquids. To protect against shortcircuit and corrosion, no water or any other liquid should be allowed to
potentially explosive gases or vapors, which could ignite, causing personal
injury and/or damage to the equipment. If such disinfectants are used, the
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Preva Dental X-ray System — User Manual
Control Unit
The Control Unit provides for the input power connection and control of the
consists of the mounting base and Operator Panel.
Tubehead
The Tubehead contains the X-ray tube, high voltage circuit, and a round
hole be blocked as it provides an air vent to allow the
Articulated Arm
The Articulated Arm provides the articulation support for the Tubehead and
Attention:
The equipment must only be installed and operated in accordance with the safety procedures and
operating instructions given in this manual and in the Installation Guide for the purposes and
applications for which it was designed. Modifications and/or additions to the equipment may only
be carried out by Midmark Corporation or by third parties expressly authorized by Midmark
Corporation to do so. Such changes must comply with legal requirements as well as with the
generally accepted technical rules. It is the responsibility of the user to ensure that existing legal
regulations regarding installation of the equipment with respect to the building are observed.
CAUTION: Do not hang lead aprons on the horizontal extension arm.
X-Ray Protection
X-ray equipment may cause injury if used improperly.
It is recommended that operators of an intraoral dental X-ray device stand a minimum of 2 meters
(6.6 feet) away from the focal spot and out of the path of the X-ray beam.
The Preva Dental X-ray System provides a high degree of protection from unnecessary X-radiation.
However, no practical design can provide complete protection nor prevent operators from exposing
themselves or others to unnecessary radiation.
The instructions contained in this manual must be read and followed when operating the
Preva. Your Midmark Sales Corporation dealer will assist you in placing the Preva in
operation.
Product Description
The Preva Dental X-ray System is a high-frequency intra-oral X-ray machine. The Preva consists of
five components, as shown in Figure 1 Component Diagram: the Control Unit, the Tubehead, the
Articulated Arm, the Horizontal Arm, the Cone, and the Remote Control option.
Tubehead and Operator Panel. It provides automatic line voltage
compensation, kVp control, and exposure time control. The Control Unit
Cone. The tubehead is shipped already assembled to the Articulated Arm.
WARNING: There is a small hole in the plastic handle covering
the back of the Tubehead. Under no circumstances should this
Tubehead oil to expand and contract as the unit is operated.
the reach and coverage of the Tubehead to the patient.
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Preva Dental X-ray System — User Manual
Horizontal Arm
The Horizontal Arm helps provide the necessary reach for the Preva. It
56, 66, 76 and 82 inches [142, 167, 193, 208 cm].
Modular Beam
The Cone establishes the distance from the X-ray tube to the patient’s skin.
(30-A2200) can be ordered as an option.
Handswitch
To make exposures in addition to or replacing the use of the exposure
Model
The Preva is available as both a wall mount and mobile unit. See the Preva
Installation and
The Preva Dental X-ray System should only be installed and serviced by
f you need assistance locating an
back cover of this manual.
Diagram
pivots around a shaft inserted in the top of the Control Unit and contains an
access cover to connect the cable from the Horizontal Arm to the Control
Unit. It is available in four lengths on wall mount units providing reaches of
Limiting Device
[BLD]
Configurations
Service
It provides positioning assistance and collimates the X-ray beam to within a
defined circle at its end. The Preva is shipped with the standard 8-inch [20
cm] Cone (30-A2195) attached to the Tubehead. A 12-inch [30 cm] Cone
button, an optional Handswitch (30-A2040) can be ordered.
Installation and Service Manual for installation and mounting instructions.
approved Midmark dealer personnel. I
approved dealer, contact Midmark Corporation using the information on the
Figure 1 Component
CAUTION: Do not hang lead aprons on the horizontal extension arm.
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Preva Dental X-ray System — User Manual
Certified Components
System
Component
Modular BLD, Spacer, White
Reference Number
30-A2208
Authorized Representatives
North
Midmark Corporation
Fax: 847-415-9801
Europe
CE Partner 4U
America
Tubehead
Control Unit. Preva
Control Unit. Preva Mobile
Modular BLD, 20 cm Lg., 70 mm Cone, Gray
Modular BLD, 30 cm Lg., 70 mm Cone, Gray
Modular BLD, 20 cm Lg., 60 mm Cone, White
Modular BLD, 30 cm Lg., 60 mm Cone, White
Modular BLD, 30 cm Lg., 60 mm Cone, Gray
Modular BLD, 20 cm Lg., 30x40 mm Cone, White
Modular BLD, 30 cm Lg., 30x40 mm Cone, White
Modular BLD, 20 cm Lg., 20x30 mm Cone, White
Modular BLD, 20 cm Lg., 35x45 mm Cone, Gray
Modular BLD, 20 cm Lg., 35x45 mm Cone, White
Modular BLD, 30 cm Lg., 35x45 mm Cone, Gray
Modular BLD, 30 cm Lg., 35x45 mm Cone, White
Modular BLD, Base, Gray
Modular BLD, Spacer, Gray
675 Heathrow Dr.
Lincolnshire, Illinois 60069 U.S.A.
Phone: 800-MIDMARK (800-643-6275)
30-A1027
30-A0010
30-A0013
30-A2195
30-A2200
30-A2196
30-A2201
30-A2229
30-A2198
30-A2203
30-A2199
30-A2221
30-A2222
30-A2223
30-A2224
30-A2205
30-A2206
Esdoornlaan 13
3951DB Maarn
The Netherlands
www.cepartner4u.eu
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Preva Dental X-ray System — User Manual
Explanation of Symbols on Technical Labels
Type B: Protection against electric shock (IEC 60601.1-1988)
Consult written instructions in User Manual.
WARNING X-RAY
ARE OBSERVED.
X-RAY EMISSION
Mains HOT WIRE
Mains NEUTRAL WIRE
Earth Ground
The symbols appearing on the product and/or in the technical manuals.
THIS X-RAY UNIT MAY BE DANGEROUS TO PATIENT AND OPERATOR
UNLESS SAFE EXPOSURE FACTORS AND OPERATING INSTRUCTIONS
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Preva Dental X-ray System — User Manual
Compliance with Applicable Standards
The following regulatory documents app
ly:
Radiation
The certified components of the Preva Dental X-ray System comply with Radiation
UL 2601-1
Classified by Underwriters Laboratories Inc. with respect to electrical shock, fire
60601-2-28.
General
IEC 60601-1:1995
oxygen or nitrous oxide.
EMI/EMC
IEC 60601-1-2:2007
Degree of
IEC 60529:2001
Imaging
IEC 61223-3-4:2000
EMC
Information regarding potential EMC interference and advice for avoidance
adjacent to other
equipment, configuration should be carefully adjusted to ensure that
electromagnetic interference (EMI) does not degrade performance.
Specifically, mobile RF communications equipment can effect medical
when integrated with
IEC 60601. If not, this may result in degraded electromagnetic
Protection
File Number:
E181750
Safety
Protection
Performance Standards 21 CFR, Subchapter J, at the time of manufacture.
The certified components of the Preva Dental X-ray System comply with IEC 606011-3 Radiation protection/X-ray equipment.
and mechanical hazards only in accordance with UL 2601-1, and CAN/CSA C22.2
NO, 601.1-M90, and to the following particular standards, IEC 60601-2-7, IEC
Protection against electrical shock – Class II
Degree of protection against electrical shock – Type BF Applied Part
Degree of protection against ingress of water – IP67
Not suitable for use in the presence of flammable anesthetic mixture with air or with
Degree of protection against ingress of water – IP67
Performance
Statement
Line pair resolution – better than 8 lp/mm
Low contrast resolution – all holes visible
• The Preva Dental X-ray System is considered as non-life-supporting
equipment. While using Preva Dental X-ray System
electrical equipment. Please refer to the EMC table below.
• Usage limitation: Preva Dental X-ray System
ClearVision Sensors shall be used with IEC 60950 or IEC 60601 compliant
computers. Also, any device between the integrated Preva Dental X-ray
System and the computer (USB Hub) shall be compliant with IEC 60950 or
compatibility.
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Preva Dental X-ray System — User Manual
Guidance and manufacturer's declaration - electromagnetic emissions
The Preva Dental X-ray System is intended for use in the electromagnetic environment specified below. The customer or the user of the
Preva Dental X-ray System should assure that it is used in such an environment.
Emission test
Compliance
Electromagnetic environment – guidance
RF emission
Group 1
The Preva Dental X-ray System uses RF energy only for its internal function. Therefore,
emissions are very low and are not likely to cause any interference in nearby
electronic equipment.
RF emission
CISPR 11
Class B
The Preva Dental X-ray System is suitable for use in all establishments, including
Harmonic emission
IEC 61000-3-2
Class A
Voltage fluctuations/
Complies
Guidance and manufacturer's declaration - electromagnetic immunity
The Preva Dental X-ray System is intended for use in the electromagnetic environment specified below. The customer or the user of the
Preva Dental X-ray System should assure that it is used in such an environment.
Compliance
level
Electromagnetic
environment – guidance
Electrostatic discharge (ESD)
± 6 kV contact
± 6 kV contact
Floors should be wood, concrete or ceramic
tile. If the floors are covered with synthetic
material, the relative humidity should be at
least 30%.
Electrical fast transient/burst
± 2 kV for power supply lines
± 2 kV for power
output lines
Mains power quality should be that of a
transient/ burst supply lines typical
Surge
IEC 61000-4-5
± 1 kV line(s) to line(s)
± 2 kV line(s) to earth
Not Applicable.
Voltage dips, interruptions,
IEC 61000-4-11
< 5% UT (>95% dip in UT) for 0.5 cycle
< 5% UT (>95% dip in UT) for 5 s
Not Applicable.
Power frequency (50/60 Hz)
IEC 61000-4-8
3 A/m
3 A/m
Power frequency magnetic fields should be at
levels characteristic of a typical location in a
typical commercial or hospital environment.
NOTE: UT is the a.c. mains voltage prior to application of the test level.
CISPR 11
flicker emissions
IEC 61000-3-3
Immunity test IEC 60601 test level
IEC 61000-4-2
IEC 61000-4-4
and voltage variations on
power supply input lines
± 8 kV air
± 1 kV for input/output lines
< 40% UT (60% dip in UT) for 5 cycles
< 70% U
(30% dip in UT) for 25 cycles
T
its RF
domestic establishments and those directly connected to the public low-voltage power
supply network that supplies buildings used for domestic purposes.
± 8 kV air
supply lines
± 1 kV for input/
commercial or hospital environment.
magnetic field
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Preva Dental X-ray System — User Manual
Guidance and manufacturer's declaration - electromagnetic immunity
The Preva Dental X-ray System is intended for use in the electromagnetic environment specified below. The customer or the user of the
Preva Dental X-ray System should assure that it is used in such an environment.
Immunity
test
IEC 60601
test level
Compliance
level
Portable and mobile RF communications equipment should be used no closer to
equipment, including cables, than the
n applicable to the
Recommended separation distance:
Conducted RF
IEC 61000-4-6
3 V
150 kHz to 80 MHz
3 V
= 1.2 ×√
Radiated RF
3 V/m
3 V/m
= 1.2 ×√
= 2.3 ×√ 800 MHz to 2.5 GHz
Where P is the maximum output power rating of the transmitter in watts (W)
is the recommended separation
d by an electromagnetic
Interference may occur in the vicinity of equipment marked with the following
NOTE 1: At 80 MHz and 800 MHz, the higher frequency range applies.
These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from
structures, objects, and people.
a
Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land mobile radios, amateur radio,
Over the frequency range 150 kHz to 80 MHz, field strengths should be less than [V1] V/m.
Recommended separation distances between portable and mobile RF communications equipment and
Preva Dental X-ray System
The Preva Dental X-ray System is intended for use in the electromagnetic environment in which radiated RF disturbances are controlled. The
communications equipment.
Rated maximum output
power of transmitter, W
Separation distance according to frequency of transmitter
m
150 kHz to 80 MHz
= 1.2 ×√
80 MHz to 800 MHz
= 1.2 ×√
80 MHz to 2.5 GHz
= 2.3 ×√
0.01
0.12
0.12
0.23
0.1
0.37
0.37
0.74 1 1.17
1.17
2.34
10
3.69
3.69
7.38
100
11.67
11.67
23.34
For transmitters rated at a maximum output power not listed above, the recommended separation distance d in meters (m) can be
guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption and reflection from
structures, objects, and people.
any part of the Preva Dental X-ray System
recommended separation distance calculated from the equatio
frequency of the transmitter.
Electromagnetic environment – guidance
IEC 61000-4-3
NOTE 2:
AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To assess the electromagnetic environment
due to fixed RF transmitters, an electromagnetic site survey should be considered. If the measured field strength in the location in which the
Preva Dental X-ray System is used exceeds the applicable RF compliance level above, the Preva Dental X-ray System should be observed to
verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as re-orienting or relocating the
Preva Dental X-ray System.
b
customer or the user of the sensor can help prevent electromagnetic interference by maintaining a minimum distance between portable and
mobile RF communications equipment (transmitters) and the sensor as recommended below, according to the maximum output power of the
80 MHz to 2.5 GHz
according to the transmitter manufacture and d
distance in meters (m).
Field strengths from fixed RF transmitters, as determine
site survey, a should be less than the compliance level in each frequency range. b
symbol:
80 MHz to 800 MHz
determined using the equation applicable to the frequency of the transmitter, where P is the maximum output power rating of the transmitter
in watts (W) according to the transmitter manufacturer.
NOTE 1: At 80 MHz and 800 MHz, the separation distance for the higher frequency range applies.
NOTE 2: These
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Preva Dental X-ray System — User Manual
Obtaining Technical Support
Contact
Midmark Corporation
Hours: 8:00 a.m. – 5:00 p.m. Central Time
675 Heathrow Dr.
Lincolnshire, Illinois 60069 U.S.A.
Phone: 800-MIDMARK (800-643-6275)
Fax: 847-415-9801
imagingtechsupport@midmark.com
13
Operating Instructions
Using the Operator Panel
Power On
When powering on the Preva Dental X-ray System, the Operator Panel
powering off the system.
Figure 2
1. Large, LED screen displays technique settings. It also displays
exposure.
1 2 3 4 5
7 8 6
9
Settings
Preva Operator
Panel
displays the selections from the most recent exposure taken prior to
Icons
14
menu selections when the system is in menu mode.
2. Up and Down arrows are used to change kV, mA and time settings.
3. Tooth Icon: Pressing this button allows the user to select Incisor,
Bicuspid, Bitewing, Upper or Lower Molar.
4. Receptor Icon: Choices are: Digital, D Speed film, E/F Speed Film.
If using phosphor plates, select E/F Speed Film Setting.
5. Patient Size Icon: Press to select Large or Small
6. Ready Indicator: Circle lights up to indicate that the system is ready
to produce X-ray.
7. Right Arrow Button: Use this button to move between kV, mA and
time selections. This button is also used as an “Enter” key when the
system is in menu mode.
8. Radiation Indicator: This symbol lights up when an X-ray is
produced.
9. Exposure Button: Pressing this button will produce an X-ray
Preva Dental X-ray System — User Manual
Exposure
When the system is powered on, the operator panel, Figure 2, displays the
ge receptor type, and patient size. Use the Tooth Selection, Image
programmed exposure settings, refer to the
Preprogrammed Exposure Settings tables in this manual.
Adjusting
Preset exposure settings can be adjusted prior to making an exposure. Use
this manual.
Exposure Button
The Exposure button is used to initiate an X-ray exposure. For a complete
When a premature release of the Exposure button occurs, the
notify the operator momentarily and then return to
Ready Indicator
The Ready Indicator illuminates when the system is ready to make an
Ready Indicator is flashing, no exposure can be made.
Radiation
The Preva has a visible and an audible Radiation Indicator. When an
heard.
Settings
Exposure
Settings
and Ready
Indicator
exposure settings (kV, mA, and seconds) for the currently selected tooth,
ima
Receptor Type, and Patient Size buttons to select other exposure settings.
For a table of the factory-
the right arrow to select the exposure setting to adjust. Then use the up and
down arrow buttons to adjust the value.
To save new presets, see the System Configuration Mode information in
exposure, the button must be pressed and held until the Radiation Indicator
no longer illuminates and the audible signal is no longer heard. Releasing
the Exposure button immediately terminates the X-ray exposure.
CAUTION: Releasing the Exposure button prior to the completion
of the X-ray exposure will result in an incomplete exposure of the
image. This may require the operator to re-take the radiograph.
system will
operating mode.
Indicators
exposure. Immediately after an exposure, the Ready Indicator flashes until
the X-ray tube cools down sufficiently to make the next exposure. When the
exposure is in progress, the Radiation Indicator on the Operator Panel is
illuminated and an audible tone is heard. The exposure is complete when
the Radiation Indicator is extinguished and the audible tone is no longer
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Preva Dental X-ray System — User Manual
Taking an X-ray
1. Turn the power switch, located at the upper right of the Control Unit, to the “On”
Position the Tubehead to the patient using standard accepted positioning
storage position.
It may be necessary to increase or decrease the kV, mA, or time from the preset
position. The Ready Indicator on the front of the Operator Panel, (Figure 2), will
light.
2. Verify that the unit is set for the correct Image Receptor Type. The icon for the
currently selected Image Receptor Type is illuminated. To change the Image
Receptor type, press the Image Receptor Type button until the correct Image
Receptor Type is selected.
3. Verify that the system is set for the appropriate Patient Size. The icon for the
currently selected Patient Size is illuminated. To change the Patient Size, press
the Patient Size button until the correct Patient Size is selected.
4. Verify that the unit is set for the Tooth to be imaged. The icon for the currently
selected Tooth is illuminated. To change the Tooth Selection, press the Tooth
Selection button until the correct Tooth is selected.
5. If desired, preset exposure settings for the combination of Image Receptor
Type, Tooth Selection, and Patient size, selected in steps 2-4, can be adjusted
prior to making an exposure. Use the right arrow to select the exposure setting
to adjust. Then use the up and down arrow buttons to adjust the value. Skip this
step if you are using preprogrammed exposure settings.
Note: When exposure settings are being adjusted, the Tooth Selection, Image
Receptor Type, and Patient Size buttons are turned off.
6.
procedures.
7. Prepare to take an X-ray.
It is recommended that operators of an intraoral dental X-ray device stand a
minimum of 2 meters (6.6 feet) away from the focal spot and out of the path of
the X-ray beam.
8. Take an X-ray. Press and hold the Exposure button until the audible signal is no
longer heard and the Radiation Indicator is no longer illuminated. Releasing the
Exposure button or coil-cord hand switch at any time will immediately terminate
the exposure.
Note: When using the coil-cord hand switch, it is recommended that the
operator exit the operatory if possible.
Note: In order to comply with regulations and good safety practices, the
technique factors must be visible to the operator from the remote location.
9. Return the Tubehead to the storage position.
Note: Be careful not to strike the Tubehead on anything when returning it to the
values for one exposure. To do so:
1. Press the Enter button to highlight the value to change.
2. Use the up or down button to increase or decrease the value (no lights on the
display will be lit to indicate the preset values).
3. Press the Exposure button.
4. Press any other button (Tooth, Film or Patient Size) to return the display to the
preset values.
For information on estimated radiation doses for all Technique Factors combinations
using the 20 cm cone, refer to “Dose Information
” section in this manual.
16
Preva Dental X-ray System — User Manual
About the 20cm Cone (30-A2195) and the 30 cm Cone (30-A2200)
The Preva Dental X-ray System is factory set for use with the standard supplied
ee the System
Configuration information in this manual.
8-inch [20 cm] Round Cone [30-A2195].
A 12-inch [30 cm] Round Cone [30-A2200] is also available.
Using the longer cone requires longer exposure times.
For instructions to set the system to use the longer cone, s
17
Recommended Maintenance
Regular Maintenance
In the interest of equipment safety, a regular maintenance program must be established. This
Midmark Corporation X-ray equipment.
Cleaning and Disinfecting
Cleaning /
Employ personal protective equipment to prevent the spread of infections.
Follow the disinfectant manufacturer’s recommendations
Cleaning
If not using a barrier, between each patient, perform the following cleaning and
maintenance program should consist of annual system function checking. It is the owner’s responsibility
to arrange for this service and to assure that the personnel performing this are fully qualified to service
Disinfecting
Methods
Clean the outside of the system using a damp towel or non-alcohol based
disinfectant.
CAUTION
• Do not allow liquids to drip into the system electronics.
• Do not spray cleaner or disinfectant directly onto the machine.
• Protect the system from contamination using barriers available
from dental distributors.
•
when using their cleaner or disinfectant.
disinfecting steps.
1. Remove gross bio-burden from the cone, handles and structure with a
disposable towel moistened with water.
2. Dry the cone, handles and structure with disposable towels.
3. Wipe the cone, handles and structure with a germicidal broad spectrum
disinfectant product following the disinfectant manufacturer’s instructions.
4. Clean any remaining disinfectant residue from the system with a disposable
towel moistened with water. This additional step prevents possible product
discoloration or corrosion.
5. Dry the cone, handles and structure with paper towels.
CAUTION: The Preva Dental X-ray System is not waterproof.
Use only moistened, not saturated, towels.
18
Checking System Functions
The following checks must be performed to complete the installation of the Preva Dental X-ray System
and as part of the recommended maintenance as indicated in the User Manual. Failure to perform these
checks may result in an installation that does not comply with U.S. Radiation Performance Standards 21
CFR Subchapter J.
CAUTION: If the Preva Dental X-ray System does not perform the functions in the
System Function Checklist, then the system is not to be used. See the
Troubleshooting section of the Installation Guide or contact Midmark
Corporation’s Imaging Technical Support.
19
Preva Dental X-ray System — User Manual
System Function Checklist
Wall Mounting
Ensure that the wall support is adequate and that the system is properly
mounted to the wall.
Labels
Ensure that all certified components bear labels that include the model and
Tubehead
Check for oil leaks or other evidence that could indicate internal damage.
Tubehead
Ensure that the Tubehead maintains its position around the horizontal axis
Tubehead for easy movement while remaining in position after moving.
Suspension
Check that all movements are smooth and quiet. Verify that the Tubehead is
properly counterbalanced for vertical drift and that the Horizontal and
Power Switch
Verify that the switch is working properly and that the Ready Indicator is
illuminated when the power switch is in the ON position.
Operator Panel
With the power switch, located at the upper right of the Control Unit, in the ON
check the function of the selection buttons for Tooth Selection, Image
indicator lamps to indicate the selected item.
Exposure Button
Verify that the Exposure button on the Operator Panel is functioning properly.
Exposure
Make several exposures and verify that the Radiation Indicator illuminates and
Premature
Select the longest exposure time possible using the up and down arrows.
“Pre-termination Error” and returns to normal operating mode.
Coil-cord Hand
If a coil-cord hand switch is used, inspect the switch housing and coil cord for
User Information
Make certain that the user of the system has received the User Manual.
serial number, date of manufacture and a statement of certification as noted
elsewhere in this manual.
Replace the Tubehead, if necessary.
Rotation
Controls
Indicators
Termination
while remaining easy to rotate and position. Also check the vertical pivot of the
Articulated Arms do not drift horizontally.
position, verify that technique factors appear on the Operator Panel. Also,
Receptor Type and Patient Size. Pressing a selection button should cause
To make an exposure, press and hold the Exposure button until the Radiation
Indicator is extinguished and the audible signal is no longer heard.
the audible signal is heard.
Initiate an exposure but release the Exposure button after a brief period of
time before the timer terminates the exposure. Verify that the display indicates
Switch Option
damage or wear. Replace if evidence of damage is present.
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Preva Dental X-ray System — User Manual
New Tube Seasoning Procedure
X-ray tubes that sit dormant for several months can become electrically unstable.
This process establishes stable high voltage operation and will
8. Make five exposures at this level, observing the normal cooling time.
To remedy this condition, it is recommended you perform a new tube seasoning
procedure.
ultimately extend the life of the tube. Repeat this procedure before returning to
normal operation any time the system has been unused for more than two months.
1. Verify system operation.
2. Energize the system.
3. Select 60 kilovolts [kV], 7 milliamperes [mA], and the exposure time of one
second.
4. Make five exposures at this level, observing the normal cooling time.
5. Select 65 kilovolts, 7 milliamperes, and the exposure time of one second.
6. Make five exposures at this level, observing the normal cooling time.
7. Select 70 kilovolts, 6 milliamperes, and the exposure time of one second.
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Preva Dental X-ray System — User Manual
Performance Issues
Light or Dark
1. Adjust the selected exposure time, kilovoltage [kV] or tube current to
ssary, reprogram the technique
and tube current during an exposure using the
invasive meter to
computer.
No X-ray
If no X-ray is produced, check the following:
Pre-termination
Early release of the exposure switch will cause a pre-termination error to occur.
Obtaining Technical Support
If the above steps do not resolve any of the error issues that you are experiencing, suspend use of the
Contact
Midmark Corporation
Solving Performance Issues
X-ray Images
Error
X-ray unit and contact Midmark Technical Support for assistance.
produce an acceptable image. If nece
factors, as explained in the System Configuration information in this
manual.
2. Verify the kilovoltage
diagnostic mode, as explained in the System Configuration section (pg. 23)
of this manual. Alternatively, you may employ a nonevaluate kilovoltage and exposure time.
3. Inspect the condition of the remaining imaging chain components such as
the film, chemistry and processor, or the condition of the X-ray sensor and
1. Verify that the line cord (if one is in use) is properly connected.
2. Verify that the power switch is in the ON position.
After five seconds, the system will return to the normal operating condition. Be
advised that this will result in an underexposed image.
675 Heathrow Dr.
Lincolnshire, Illinois 60069 U.S.A.
Phone: 1-800-MIDMARK (800-643-6275)
Fax: 847-415-9801
imagingtechsupport@midmark.com
Hours: 8:00 a.m. – 5:00 p.m. Central Time
22
Preva Dental X-ray System — User Manual
The tables below show the factory default exposure settings for each combination of Tooth, Image
the System Configuration mode. For details, see the System Configuration Mode section.
System Configuration
Preprogrammed Exposure Times
Receptor Type, and Patient Size on the Operator Panel. These exposure settings can be modified using
Note: To see the dosages for kV and mA combinations, see the " Dos e Information
manual.
" section of this
23
Preva Dental X-ray System — User Manual
w down to Exit and press the right arrow key then
Changing Language
Five languages are preprogrammed in the display panel. To change follow the
steps below.
1. Push and hold the Tooth and Patient selection switches, a menu screen
will appear after about 5 seconds. (See Figure 3)
2. Using the down arrow highlight “Configure Unit” and press the right arrow
key. (See Figure 3)
3. “Select Languages” on the next screen is highlighted press the right arrow
key.
4. Select the desired language and press the right arrow key. If you do not
see your desired language listed arrow down to “More” and press the right
arrow key.
5. After selection arro
repeat this procedure to return to the main screen.
Figure 3
Preva Operator
Panel
24
Preva Dental X-ray System — User Manual
System Configuration Mode
About System
The Preva Dental X-ray System has a software-driven system configuration
• Displaying Diagnostic Data
Using System
1. To enter system configuration mode, depress the Tooth Selection and
seconds. The display shows the Main System Configuration menu, as
decrease values.
Configuration
Mode
Configuration
Mode
mode. When the Preva is in system configuration mode, you can perform the
following procedures:
• Adjusting the Display
• Changing Preprogrammed Exposure Settings
• Changing the Cone Size
• Showing Current System Configuration
Patient Size Selection buttons on the Operator Panel simultaneously for 5
shown in Figure 4, and the Ready Indicator blinks.
2. To select menu items while in system configuration mode, use the up and
down arrows to highlight a menu option. Then use the right arrow button as
an Enter button to select the highlighted option. When changing presets, the
right arrow button is also used to select the technique factor.
3. After selecting a menu option, use the up and down arrows to increase or
Figure 4
Main System
Configuration Menu
25
Preva Dental X-ray System — User Manual
Adjusting the Display
The Preva Dental X-ray System allows the operator to adjust the display image.
shown in Figure 4.
Adjusting
1. Select ADJUST CONTRAST from the menu. You will see the Progeny
logo.
3. Press the right arrow to save your settings.
Reversing the
1. Select REVERSE IMAGE from the menu. The text and display background
1. From the system configuration main menu, shown in Figure 4, select ADJUST
DISPLAY. You will see the Display Options menu shown in Figure 5.
2. Selecting EXIT returns the display to the Main System Configuration menu
Contrast
2. Use the up and down arrows to increase or decrease the contrast between
the menu text and the display background.
®
Image
Figure 5
Display Options
Menu
colors will be swapped.
2. Press the right arrow to save your settings.
26
Preva Dental X-ray System — User Manual
Changing Preprogrammed Exposure Settings
The Preva Dental X-ray System allows the operator to increase or decrease
settings, refer to Factory
cone will reset exposure
Displaying the
1. From the Main System Configuration menu, shown in Figure 4, select
shown in Figure 4.
Changing All
1. Select ALTER DENSITIES from the Preset Options menu. The first Image
Receptor Type illuminates. The display shows the selected Image
Using the Image Receptor Type button, select the image receptor to
densities will be increased or decreased for the selected receptor.
4. Press Enter to save your settings.
image density for all presets for a receptor simultaneously or to change each of
the technique factors for a preset individually. You can also restore factory
default settings. For charts of the factory default
Preprogrammed Exposure Settings section in this manual.
Note: If the 12-inch [30 cm] cone is going to be used, configure the Preva for
use with the 12-inch cone before changing preprogrammed exposure settings.
Configuring the Preva for use with the 12-inch
settings to the default settings used with the 12-inch cone.
Note: Before changing presets, use one of the Record your Exposure Settings
tables provided in this manual to record the presets you are programming.
Make sure to use the correct table (for 8-inch cone or 12-inch cone) based on
the cone size being used.
Preset Options
Menu
Figure 6
Preset Options Menu
Receptor
Settings Globally
CHANGE PRESETS. You will see the Preset Options menu shown in Figure
6.
2. Selecting EXIT returns the display to the Main System Configuration menu
Receptor Type and current density.
2.
adjust.
3. Use the up and down arrow buttons to specify a percentage by which
Densities can be increased or decreased according to values provided on
the display.
27
Preva Dental X-ray System — User Manual
Preprogramming
1. Turn the system on.
: When you are working in service mode, the green light next to the
Changing Presets
1. Turn the system on.
you that you are entering Edit Preset Mode, and Tooth Size, Image
change.
Recall Presets
1. Turn the system on.
5. Select NO using the down arrow button and retain current presets.
to Digital Sensors
Individually
2. Push and hold the Tooth and Patient selection switches, a menu screen
will appear after about 5 seconds.
3. Select CHANGE PRESETS from the Menu Options screen.
4. Select SELECT RECEPTOR from the Preset Options menu (Figure 6).
5. Press the up or down button to highlight the sensor or phosphor plate to
change, and press Enter.
6. Select YES or NO on the Verification screen.
7. Exit the Preset Options menu.
8. Exit the Menu Options menu. A message of “Saving Settings” will display
briefly, and then the system will return to the normal operational mode.
Note
exposure button will blink.
2. Push and hold the Tooth and Patient selection switches, a menu screen
will appear after about 5 seconds.
3. Select EDIT PRESETS from the Preset Options menu. The display notifies
Receptor Type, and Patient Size are illuminated.
4. Use the Tooth Selection, Image Receptor Type, and Patient Size Selection
buttons to select the preset to change. The display shows the current
values for the preset.
5. Use the right arrow button to highlight the technique factor (tube voltage
in kilovolt [kV], tube current in milliamp [mA] or duration in seconds [s]) to
change.
6. Use the up and down arrow buttons to set the value for the selected
technique factor and preset.
7. Repeat steps 2-4 to change additional presets.
8. When you have completed all changes, press the Tooth Selection and
Patient Size Selection buttons simultaneously for 5 seconds to record the
2. Push and hold the Tooth and Patient selection switches, a menu screen
will appear after about 5 seconds.
3. To return all presets to factory defaults, select RECALL PRESETS from the
Preset Options menu. The menu will ask you to confirm your choice.
4. Select YES using the up arrow button and return all presets to factory
default settings. Selecting YES will erase any custom presets that have
been set up.
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Preva Dental X-ray System — User Manual
8-inch (20 cm) Cone
Digital Receptor
D-speed Film
E/F Speed Film
Tooth Selection
Setting
Adult
Child
Adult
Child
Adult
Child
Incisor
kV
mA
seconds
Bicuspid
kV
mA
seconds
Bitewing
kV
mA
seconds
Lower
kV
mA
seconds
Upper
kV
mA
seconds
Record Your Exposure Settings (8” [20 cm] Cone)
If the preprogrammed exposure settings do not produce the density desired, adjust the settings using
System Configuration mode. Record your settings in the table below.
Molar
Molar
29
Preva Dental X-ray System — User Manual
12-inch (30 cm) Cone
Digital Receptor
D-speed Film
E/F Speed Film
Tooth Selection
Setting
Adult
Child
Adult
Child
Adult
Child
Incisor
kV
mA
seconds
Bicuspid
kV
mA
seconds
Bitewing
kV
mA
seconds
Lower
kV
mA
seconds
Upper
kV
mA
seconds
Record Your Exposure Settings (12” [30 cm] Cone)
If the preprogrammed exposure settings do not produce the density desired, adjust the settings using
System Configuration mode. Record your settings in the table below.
Molar
Molar
30
Preva Dental X-ray System — User Manual
Showing Current System Configuration
The Preva Dental X-ray System displays the current system configuration. This
, select
Press any button on the Operator Panel to return to the Configuration
menu.
display is informational only.
1. From the Main System Configuration menu, shown in Figure 4
CONFIGURE UNIT. You will see the Configuration menu shown in Figure 7.
2. Select SHOW CONFIG. The display will show:
• Current software version
• Cone size
• Diagnostic mode on or off
3.
Figure 7
Configuration
Menu
31
Preva Dental X-ray System — User Manual
Changing the Cone Size
Selecting SET CONFIG. from the Configuration menu, shown in Figure 7,
menu.
Using a 12-inch
1. From the Main System Configuration menu, shown in Figure 4, select
5. Using the up arrow, select YES to install presets for the 12-inch Cone.
displays the Set Configuration menu, Figure 8, with options to change the cone
size. The Preva Dental X-ray System is factory set for use with the standard
supplied 8-inch [20 cm] Cone. The 12-inch [30 cm] Cone [30-A2200] is available.
Using the longer Cone requires longer exposure times, which the Preva
automatically selects when you change the Cone size in the Set Configuration
[30 cm] Cone
Figure 8
Set Configuration
Menu
CONFIGURE UNIT. You will see the Configuration menu shown in Figure 7.
2. Select SET CONFIG. You will see the Set Configuration menu, shown in
Figure 8.
3. From the Set Configuration menu, use the up and down arrows to highlight
12” CONE SIZE.
4. Press the right arrow button to select the 12” CONE. The display warns you
that selecting the 12-inch Cone will override custom presets with the default
factory settings for the 12-inch Cone.
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Preva Dental X-ray System — User Manual
Diagnostic Mode
About
The Preva Dental X-ray System has a diagnostic mode in which you can display
a summary of maintenance data or display feedback values after each
Showing the
1. From the Main System Configuration menu, shown in Figure 4, select
. The following maintenance data are
4. Press any button on the Operator Panel to return to the Configuration menu.
Showing
If you take an X-ray (following the steps in “T ak ing an X -ray”) while in diagnostic
, select
press the Tooth Selection and Patient Size
the Set Configuration menu, highlight and select DIAG MODE OFF.
Diagnostic
Mode
Maintenance
Summary
Feedback
Values After an
Exposure
exposure.
CONFIGURE UNIT. You will see the Configuration menu shown in Figure 7.
2. Select SET CONFIG. You will see the Set Configuration menu, shown in
Figure 8.
3. To display a summary of maintenance data, highlight select SHOW MAINT
from the Configuration menu
displayed:
• Total kJ (kilojoules—total system heat on X-ray tube)
• Exposure Count
• Reboots (power up cycles)
• OT Counts (over-threshold counts)
mode, the display shows feedback values for that exposure. Until you exit
diagnostic mode, the display will continue to show feedback values after each
exposure.
1. From the Main System Configuration menu, shown in Figure 4
CONFIGURE UNIT. You will see the Configuration menu shown in Figure 7.
2. Select SET CONFIG. You will see the Set Configuration menu, shown in
Figure 8.
3. From the Set Configuration menu, use the up and down arrows to highlight
DIAG MODE ON. Press the right arrow button to turn on diagnostic mode.
4. Exit System Configuration mode by highlighting and selecting EXIT in the
Configuration and Main menus.
5. Prepare to take an X-ray.
It is recommended that operators of an intraoral dental X-ray device stand a
minimum of 2 meters (6.6 feet) away from the focal spot and out of the path
of the X-ray beam.
6. Take an X-ray.
The display will show the following feedback values:
• kV
• mA
• Filament current
7. Press any button on the Operator Panel to clear the feedback values from
the display.
8. To exit diagnostic mode,
Selection buttons simultaneously for 5 seconds to display the Main System
Configuration menu. From the Main System Configuration menu, highlight
and select CONFIGURE UNIT. Then highlight and select SET CONFIG. On
33
Preva Dental X-ray System — User Manual
Preva Dental X-ray System
Line Voltage
AC 100 V to 250 V, 50 Hz or 60 Hz
Line Load
250 V, UL Recognized – It is recommended that branch circuit does
not exceed 15A
Tube Potential
60 kV, 65 kV, 70 kV
Tube Current
4 mA, 5 mA, 6 mA, 7 mA (7 mA is not available at 70 kV)
Irradiation Time
20 ms through 2 s
Maximum Deviation from
Peak tube potential, maximum deviation: ±5%
Exposure time: min 20 ms, max. 2 s, max. deviation: ±5%+1 ms
Minimum Source to Skin
8-inch cone (20 cm)
Focal Spot
0.4 mm (per IEC 60336)
Operating Temperature
+50 °F to +95 °F (+10 °C to +35 °C)
Storage Temperature
-31 °F to +150 °F (-35 °C to +66 °C)
Maximum Altitude
12,000 ft (3,657 m)
X-ray Beam Dimension
Diameter of 2.72 inches (7 cm) at the end of the 7 inch Cone.
Cones with smaller diameter or rectangular beams are available.
Humidity Range
10 to 80 % non-condensing
Specifications
Indicated Values
Distance
(Operation & Storage)
Tube current, maximum deviation: ±1 mA
12-inch cone (30 cm)
34
Preva Dental X-ray System — User Manual
Statements and Information According to 21 CFR Sub Chapter J
1020.30 (h) (1) (i)
Instructions for the use of the Preva and precautionary statements are
part of this User’s Manual.
1020.30 (h) (1) (ii)
As described in the Recommended Maintenance section, the Preva
Midmark Corporation X-ray equipment.
1020.30 (h) (2) (i)
Leakage technique factors: 70 kV, 0.4 mA
equivalent at 70 kV
1020.30 (h) (2) (ii)
The cooling curve charts for the anode can be found on page 36.
meaningful separate cooling curve for the tube housing.
1020.30 (h) (2) (iii)
Since the Preva operates as a complete system in only one mode as
1020.30 (h) (3) (i)
Rated nominal line voltage: 110 V – 230 V
Line voltage regulation: 10% of the nominal line voltage
1020.30 (h) (3) (ii) and (iii)
The maximum momentary line current (less than 5 s) of the Preva is
65 kV, 7 mA, 2 s.
1020.30 (h) (3) (v)
Generator rating at maximum technique factor of 65 kV, 7 mA is
455 W. Duty cycle is 1:15.
1020.30 (h) (3) (vi)
Maximum deviation from indicated values:
1020.30 (h) (3) (viii)
The measurement criteria for all technique factors used in
tube voltage.
should be serviced on an annual basis to ensure proper functionality.
It is the owner’s responsibility to arrange for this service and to assure
that the personnel performing this service are fully qualified to service
Minimum filtration (half-value layer) in useful beam: 1.7 mm Al
Please note that due to the integrated design of the Preva, there is no
a high frequency X-ray system, there is no need to provide a tube
rating chart.
10 A when operated on 120 V (1.2 kW). Operation at higher input
voltage will reduce the maximum current (5 A at 240 V). The
technique factors producing the maximum momentary line current are
a) Peak tube potential, maximum deviation: ±5%
b) Tube current, maximum deviation: ±1 mA
c) Exposure time: min 20 ms, max. 2 s, max. deviation: ±5%+1 ms
paragraphs (h) (3) (iii), and (h) (3) (vi) is 90% of the selected peak
35
Preva Dental X-ray System — User Manual
Thermal Characteristics Charts
Figure 9
Toshiba Tube Rating
Chart
Figure 10
Kailong Tube Rating
Chart
Thermal Characteristics Chart
36
Preva Dental X-ray System — User Manual
2(h)(i)-(iv)
For each X-ray tube assembly:
2(i)
Duty cycles: 1:15
2(j)
To operate the equipment at the maximum line current, the following are necessary:
2(k)
Loading factors that constitute the maximum line current condition for the X-ray generator:
2(l)
Recommended loading factors for each patient size: refer to the System Configuration
Statements and Information According to Canadian Radiation
Emitting Devices Regulations, Part II of Schedule II
Specifications Pr eva
• Nominal focal spot size: is 0.4 mm.
• Cooling curves for the anode and X-ray tube housing: refer to the Thermal
Characteristics Charts in the Specifications
• X-ray tube rating charts: refer to the tube rating figures within the Specifications
section of the Preva Installation and Service Manual (00-02-1577).
• Focal spot position: the following illustration shows the focal spot position and the
focal spot marks on the Preva tubehead.
section of this manual.
Rectification type: Constant potential, high frequency
Generator rating: 60 kV, 65 kV, 70 kV
• Nominal line voltage: AC 110 V to 230 V, 50 Hz or 60 Hz
• Maximum line current: 10 A
• Line voltage regulation: 10% of the nominal line voltage
65 kV, 7 mA, 2 s
section of this user manual.
37
Preva Dental X-ray System — User Manual
2(o)
The operating range and the maximum deviation for any setting within the operating
Factor
Nominal Value
Deviation
Peak Tube Potential
60kV, 65kV, 70kV
±5%
Tube Current
4mA, 5mA, 6mA, 7mA
±20%
Exposure Duration
min 20 ms, max. 2 s
±5% of 20ms, whichever is greater
2(q)
Removable protective de vic es : the m odular beam-limiting devices (BLDs) available for
3(a)
Shape and dimension of the exit field: the shape and dimension of the exit field is
3(b)(ii)
Nominal X-ray image receptor air kerma range that is needed for the intended use:
3(b)(iii)
Recommendations for typical loading factors at specified distances between the focal
3(c)
The method by which the distance between the focal spot and the skin can be
3(e)(i)
For the air kerma at a given distance from the focal spot for every selectable
3(e)(ii)
The maximum deviation of the air kerma: refer to the Dose Information section of this
range for each loading factor are summarized below:
Note: 7mA is not
available for 70kV.
use with Preva are described in the Product Description section and listed by part
number in the Certified Components section of this user manual. Information on the
effectiveness of the BLDs is provided in the Dose Information section. Instructions for
BLD replacement are provided in Technical Advisory Notice (TAN) 55-60-004,
available in the Midmark.com Technical Library.
determined by the size of the BLD. For a list of available BLD sizes, refer to the
Certified Components section of this user manual.
refer to the Dose Information section of this user manual. For dose administered
when using the ClearVision sensor, refer to the Dose Information section of the
ClearVision Installation and User Manual (00-02-1663).
spot and the skin of 20 cm to achieve the air kerma referred to in subparagraph (ii):
refer to the
Dose Information section of this user manual.
determined using the focal spot indicators is determined by the length of the BLD. For a
list of available BLD sizes, refer to the
Certified Components section of this user
manual.
combination of loading factors, refer to the Dose Information section of this user
manual.
user manual.
38
Preva Dental X-ray System — User Manual
Dose Information
The X-ray tube output is defined as the quotient of the air kerma at a specified distance from the X-ray
tube focus by the tube current–exposure time product. The Preva X-ray tube output at 20 cm is shown in
the following table.
Table 1: Preva X-ray tube output at 20 cm from the X-ray tube focus
Peak X-ray Tube Voltage 60 kV 65 kV 70 kV
X-ray Tube Output
The Preva X-ray tube output is not calibrated to the listed values and may change over the life of the
product. The presented data are based on statistical analysis of limited number of measurements made
on a limited number of Preva intraoral X-ray systems. The maximum deviation of the estimate does not
exceed 40% with confidence 99.9%. Calibrated measurement equipment must be used periodically,
and at least annually, to obtain precise values for the X-ray tube output and air kerma for each individual
machine at the technique factors of interest.
The incident air kerma is defined as the kerma to air from an incident X-ray beam measured on the
central beam axis at the position of the patient surface. Only the radiation incident on the patient or
phantom and not the backscattered radiation is included.
The incident air kerma for Preva at 20 cm from the X-ray tube focus is shown in the following table. The
values are calculated based on the X-ray tube output.
1.374 mGy·mA⁻¹·s⁻¹ 1.560 mGy·mA⁻¹·s⁻¹ 1.783 mGy·mA⁻¹·s⁻¹
Table 2: Preva incident air kerma at 20 cm from the X-ray tube focus
Exposure
Time
0.020 s 0.110 mGy 0.137 mGy 0.165 mGy 0.192 mGy 0.125 mGy 0.156 mGy 0.187 mGy 0.218 mGy 0.143 mGy 0.178 mGy 0.214 mGy
0.025 s 0.137 mGy 0.172 mGy 0.206 mGy 0.240 mGy 0.156 mGy 0.195 mGy 0.234 mGy 0.273 mGy 0.178 mGy 0.223 mGy 0.267 mGy
0.032 s 0.176 mGy 0.220 mGy 0.264 mGy 0.308 mGy 0.200 mGy 0.250 mGy 0.300 mGy 0.349 mGy 0.228 mGy 0.285 mGy 0.342 mGy
0.040 s 0.220 mGy 0.275 mGy 0.330 mGy 0.385 mGy 0.250 mGy 0.312 mGy 0.374 mGy 0.437 mGy 0.285 mGy 0.357 mGy 0.428 mGy
0.050 s 0.275 mGy 0.344 mGy 0.412 mGy 0.481 mGy 0.312 mGy 0.390 mGy 0.468 mGy 0.546 mGy 0.357 mGy 0.446 mGy 0.535 mGy
0.064 s 0.352 mGy 0.440 mGy 0.528 mGy 0.616 mGy 0.399 mGy 0.499 mGy 0.599 mGy 0.699 mGy 0.456 mGy 0.571 mGy 0.685 mGy
0.080 s 0.440 mGy 0.550 mGy 0.660 mGy 0.769 mGy 0.499 mGy 0.624 mGy 0.749 mGy 0.874 mGy 0.571 mGy 0.713 mGy 0.856 mGy
0.100 s 0.550 mGy 0.687 mGy 0.824 mGy 0.962 mGy 0.624 mGy 0.780 mGy 0.936 mGy 1.092 mGy 0.713 mGy 0.892 mGy 1.070 mGy
0.125 s 0.687 mGy 0.859 mGy 1.031 mGy 1.202 mGy 0.780 mGy 0.975 mGy 1.170 mGy 1.365 mGy 0.892 mGy 1.114 mGy 1.337 mGy
0.160 s 0.879 mGy 1.099 mGy 1.319 mGy 1.539 mGy 0.998 mGy 1.248 mGy 1.498 mGy 1.747 mGy 1.141 mGy 1.426 mGy 1.712 mGy
0.200 s 1.099 mGy 1.374 mGy 1.649 mGy 1.924 mGy 1.248 mGy 1.560 mGy 1.872 mGy 2.184 mGy 1.426 mGy 1.783 mGy 2.140 mGy
0.250 s 1.374 mGy 1.718 mGy 2.061 mGy 2.405 mGy 1.560 mGy 1.950 mGy 2.340 mGy 2.730 mGy 1.783 mGy 2.229 mGy 2.675 mGy
0.320 s 1.759 mGy 2.198 mGy 2.638 mGy 3.078 mGy 1.997 mGy 2.496 mGy 2.995 mGy 3.494 mGy 2.282 mGy 2.853 mGy 3.423 mGy
0.400 s 2.198 mGy 2.748 mGy 3.298 mGy 3.847 mGy 2.496 mGy 3.120 mGy 3.744 mGy 4.368 mGy 2.853 mGy 3.566 mGy 4.279 mGy
0.500 s 2.748 mGy 3.435 mGy 4.122 mGy 4.809 mGy 3.120 mGy 3.900 mGy 4.680 mGy 5.460 mGy 3.566 mGy 4.458 mGy 5.349 mGy
0.640 s 3.517 mGy 4.397 mGy 5.276 mGy 6.156 mGy 3.994 mGy 4.992 mGy 5.990 mGy 6.989 mGy 4.564 mGy 5.706 mGy 6.847 mGy
0.800 s 4.397 mGy 5.496 mGy 6.595 mGy 7.694 mGy 4.992 mGy 6.240 mGy 7.488 mGy 8.736 mGy 5.706 mGy 7.132 mGy 8.558 mGy
1.000 s 5.496 mGy 6.870 mGy 8.244 mGy 9.618 mGy 6.240 mGy 7.800 mGy 9.360 mGy 10.920 mGy 7.132 mGy 8.915 mGy 10.698 mGy
1.250 s 6.870 mGy 8.588 mGy 10.305 mGy 12.023 mGy 7.800 mGy 9.750 mGy 11.700 mGy 13.650 mGy 8.915 mGy 11.144 mGy 13.373 mGy
1.600 s 8.794 mGy 10.992 mGy 13.190 mGy 15.389 mGy 9.984 mGy 12.480 mGy 14.976 mGy 17.472 mGy 11.411 mGy 14.264 mGy 17.117 mGy
2.000 s 10.992 mGy 13.740 mGy 16.488 mGy 19.236 mGy 12.480 mGy 15.600 mGy 18.720 mGy 21.840 mGy 14.264 mGy 17.830 mGy 21.396 mGy
4 mA 5 mA 6 mA 7 mA 4 mA 5 mA 6 mA 7 mA 4 mA 5 mA 6 mA
Note: The röntgen (R), the legacy unit of quantity exposure, was used prior to the use of air kerma. Values of
exposure in röntgen can be converted to air kerma in gray using the conversion 0.876×10–2 Gy/R. Similarly, air kerma
values in gray can be converted to exposure in röntgen using the conversion 114 R/Gy
60 kV 65 kV 70 kV
39
Preva Dental X-ray System — User Manual
Fax: 847.415-9801
Manufacturer
Midmark Corporation
675 Heathrow Drive
Lincolnshire, IL 60069 USA
Phone: 847-415-9800
www.midmark.com
Contacting Technical Support
Phone: 1-800-MIDMARK (1-800-643-6275)
Hours: 8:00 a.m. – 5:00 p.m. Central Time
Email: imagingtechsupport@midmark.com
Technical Library
www.midmark.com/technical-library
40
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