User Manual
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Contents
Operating Manual
Technical Manual
Service Manual
D596.131.00/05 en 2016-01 ext/Hn
General Information
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
General Information
– The product bears the CE-mark "CE 0124"
in accordance with the Council Directive
93/42/EEC about Medical Devices and fulfills
the essential requirements of Annex I of this
directive. The product is a class IIb device
(MDD).
– Product standards
The product fully complies with the requirements of the following standards:
– IEC 60731
– Electrical Safety
The product fully complies with the requirements of the following standards:
– IEC 61010-1
– Electromagnetic compatibility
The product fully complies with the requirements of the following standards:
– IEC 60601-1-2
– PTW-Freiburg cannot be held liable for dam-
age resulting from the use of accessories
or consumables from other manufacturers or
when the user ignores the instructions and
information given in this manual.
– The warranty period is 1 (one) year and begins
on the day of delivery. It is unaffected by
repairs covered by the warranty regulations.
– PTW-Freiburg only considers itself responsi-
ble for the safety, reliability, and performance
of the product if the assembly, extension, readjustment, modification, or repair is carried out
by PTW-Freiburg or by persons authorized by
PTW-Freiburg, and if the product is used in
compliance with the technical documentation.
– In case of any questions concerning the ser-
vice, support, or warranty, please contact your
supplier.
– The user manual is an integral part of the prod-
uct. It should always be kept near the product.
Observance of the manual is a prerequisite for
proper product performance and correct operation.
– Operator safety, specified measuring accu-
racy, and interference-free operation can
only be guaranteed if original products and
parts are used. Furthermore, only the accessories listed in this manual are approved by
PTW-Freiburg and only they or other accessories whose use has been expressly permitted by PTW-Freiburg may be used in conjunction with the product. Safe operation and
proper product performance are not guaranteed if accessories or consumables from other
manufacturers are used.
– This manual is in conformity with the product
specifications and all applicable safety standards that are valid as at the printing date. All
rights are reserved for devices, circuits, techniques, software, and names as referred to in
the manual.
– PTW-Freiburg reserves the right to make mod-
ifications.
Please contact PTW or your local representative for the most current information concerning the products of interest.
– No part of the technical documentation may
be reproduced without written permission from
PTW-Freiburg.
2 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
General Information
– PTW-Freiburg is a registered manufacturer
according to the ElektroG (Elektro- und Elektronikgeräte-Gesetz).
Elektro-Altgeräte-Register (EAR). Registration
number DE15599992
– PTW-Freiburg works in strict accordance with
a quality management system that is continuously updated according to the national and
international standards.
PTW-Freiburg
Physikalisch-Technische Werkstätten
Dr. Pychlau GmbH
Lörracher Str. 7
79115 FREIBURG
Germany
Tel.: +49 761 49055-0
Fax: +49 761 49055-70
info@ptw.de
www.ptw.de
D596.131.00/05 en 3
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Table of Contents
Table of Contents
General Information........................................................................................................2
Table of Contents........................................................................................................... 4
List of Figures.................................................................................................................5
Intended Use................................................................................................................... 6
Safety Information.......................................................................................................... 7
Operating Manual...........................................................13
1 Application................................................................................................................. 13
2 Measuring Ranges.................................................................................................... 18
Technical Manual...........................................................21
3 Technical Specifications.......................................................................................... 21
4 Electromagnetic Compatibility according to IEC 60601-1-2..................................29
5 Accessories and Spare Parts.................................................................................. 35
Service Manual...............................................................37
6 Cleaning......................................................................................................................37
7 Preventive Maintenance........................................................................................... 39
8 Disposal of the Product........................................................................................... 40
Literature........................................................................................................................41
Index...............................................................................................................................42
4 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
List of Figures
List of Figures
Figure 1: Farmer chamber types 30010, 30011, 30012................................................................................... 6
Figure 2: Farmer chamber type 30013............................................................................................................. 6
Figure 3: Definition of the patient environment...............................................................................................12
Figure 4: Drawing of the Farmer chamber type 30010 (dimensions in mm)..................................................24
Figure 5: Drawing of the Farmer chamber type 30013 (dimensions in mm)..................................................24
Figure 6: Drawing of the Farmer chamber type 30011 (dimensions in mm).................................................. 28
Figure 7: Drawing of the Farmer chamber type 30012 (dimensions in mm)..................................................28
D596.131.00/05 en 5
Intended Use
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Intended Use
Farmer chambers types 30010, 30011, 30012,
and 30013 are standard chambers for absolute
and relative dosimetry in combination with precision electrometers according to IEC 60731.
With their outside dimensions they are compatible
with the Farmer chambers from other manufacturers. The chambers differ in the material used for
the chamber walls and for the central electrode.
Furthermore, the Farmer chamber type 30013 is
waterproof. The chambers are used for measurements in the radiation beam in radiotherapy or for
reference purposes in secondary standard laboratories.
The Farmer chambers types 30010, 30011,
30012, 30013 will be referred to as detectors in
the following chapters. A differentiation between
the Farmer chambers types 30010, 30011, 30012,
and 30013 is only made when necessary due to
technical differences.
Figure 1: Farmer chamber types 30010,
30011, 30012
Figure 2: Farmer chamber type 30013
6 D596.131.00/05 en
Type 30010, 30011, 30012, 30013
Safety Information
Farmer Chamber
Ionization Chamber
Safety Information
This is the safety alert symbol. It is used
to alert the user to potential hazards.
Obey all safety messages that follow this
symbol to avoid any possible bodily injury
or equipment damage.
All safety messages consist of the following components:
– Safety alert symbol and signal word
– Type of danger
– Source of danger
– Consequence
– Measures to prevent hazards.
Signal Words
DANGER
Indicates an imminent hazard. If not avoided,
the hazard will result in death or serious injury.
WARNING
Indicates a hazard. If not avoided, the hazard
can result in death or serious injury.
CAUTION
Indicates a potential hazard. If not avoided, the
hazard can result in minor or moderate injury.
NOTICE
Indicates a potential hazard. If not avoided, the
hazard can result in product damage.
HINT
Provides application tips or other useful information to ensure that you get the most from
your equipment.
D596.131.00/05 en 7
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Safety Information
Safety Information
Strictly observe the following safety information concerning the signal words DANGER and
WARNING. Failure to do so endangers the lives
of the patient, user, and other persons involved.
DANGER
Operation in areas where an explosion may
occur or in oxygen-enriched atmospheres.
Explosion Hazard!
Do not operate the product in areas of risk
where an explosion may occur. Explosion
hazards may be caused, for example, by the
use of combustible anesthetics, skin-cleansing
agents, and disinfectants.
Do not operate the product in oxygen-
enriched atmospheres. The atmosphere is
considered to be oxygen-enriched when more
than 25 % of oxygen or nitrous oxide is added
to the ambient air.
DANGER
Electricity is a source of risk, particularly when
the product is not in perfect operating condition
or when it is operated inappropriately.
Shock Hazard!
– Switch on products on which moisture con-
densation has developed as a result of temperature changes only after they are completely dry.
– Liquids must not enter the product. If liquids
have entered the product, dry the product
or wait for it to dry completely. The product must be thoroughly inspected by service
personnel before being used again.
DANGER
Electricity is a source of risk, particularly when
the product is not in perfect operating condition
or when it is operated inappropriately.
Shock Hazard!
– Before using the product, verify that it is in
correct working order and operating condition.
– Before putting the product into operation,
inspect all connection cables, connectors,
housing, and covers for signs of damage.
Replace damaged cables and connectors
immediately.
8 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Safety Information
DANGER
Electricity is a source of risk, particularly when
the product is operated inappropriately.
Shock Hazard!
Exclusion of operation in the patient environment:
Do not operate the product nor any peripheral devices in the patient environment (see
Figure 3).
Exclusion of operation with patient contact:
The product is not intended for use in direct
contact with the patient. Ensure that neither the
product nor any peripheral devices come into
contact with the patient.
DANGER
Electricity is a source of risk, particularly when
the product is operated inappropriately.
Shock Hazard!
Use of peripheral devices:
Connect only peripheral devices (PC, printer)
that meet the requirements of the standard
IEC 60950-1 (UL 60950-1) or the standard
IEC 61010-1.
Connect devices to other devices or to parts
of systems only if it has been ascertained that
this connection does not impair the safety of the
patient, the operator, or the environment.
If the device specifications do not contain information regarding the connection of the device
to other equipment, consult, for example, the
manufacturers of the other equipment or other
informed experts to verify that the connection
does not impair the safety of the patient, operator, or environment. Always observe the standard IEC 61010-1.
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Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Safety Information
WARNING
Improper handling.
Hazards to Persons!
The product is a medical device and must
only be handled by persons who are trained
in the use of such equipment and are capable
of applying it properly. The operator must be
trained in the use and operation of the product.
WARNING
Magnetic and electrical fields are capable of
interfering with the proper performance of the
product.
Product Failure!
– When operating the product, make sure that
all external devices operated in its vicinity comply with the relevant EMC requirements. X-ray equipment, MRI devices, radio
systems, cell phones, etc. are possible
sources of disturbance as they may emit
higher levels of electromagnetic radiation.
Keep the product away from these devices
and verify its performance before use.
– Do not use cables longer than specified.
This might impair the electromagnetic compatibility characteristics of the product.
WARNING
Radiation is a source of risk, particularly when
the product is operated inappropriately.
Risks to Persons!
Exclusion of operation as a controlling
instrument:
Use the product as a measuring device only. Do
not use measuring results to control an equipment that produces radiation, e.g., a radiodiagnostic equipment or a radiotherapy unit.
WARNING
Application for uses other than those stated in
the user manual.
Bodily Injury! Equipment Damage!
Always apply the product in compliance with its
intended use.
Failure to do so may lead to severe or even fatal
injuries and/or equipment damage and may
void the warranty.
WARNING
Hazards originating from other system components.
Hazards to Persons! Equipment Damage!
– Do not use the product in the immedi-
ate vicinity or placed on top of or below
other equipment. However, if the application requires an arrangement of devices
as described above, the product should be
monitored in order to ensure its proper functioning in the specific arrangement.
– Make sure that the product is used in an
electromagnetic environment as described
in IEC 60601-1-2.
10 D596.131.00/05 en
Observe the safety information provided in the
user manuals of the system components.
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Safety Information
CAUTION
Use of the product without observing the user
manual.
Bodily Injury! Equipment Damage!
Always use the product in compliance with the
user manual. Otherwise, the provided protection may be impaired.
Use the product only in conjunction with
the products approved by PTW for this purpose and/or the products listed in the section
"Intended Use".
Use the product within the rated range of use
as indicted in the section "Technical Specifications".
Handle the product with care.
NOTICE
To avoid damage to the cables and connectors,
observe the following points:
– Do not kink the cables. Observe the stated
minimum bend radius of the cables. Never
exert pressure on the cables. Do not step
on the cables. Do not roll trolleys over the
cables. Do not pull or twist the cables.
– Disconnect the cables from the devices dur-
ing transport and when the devices are not
in use. Do not let the cables hang down
unrestrained.
– The connectors must always be clean. Do
not allow connectors to lie on the floor.
Always protect connectors when pulling
them through cable conduits.
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Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Safety Information
HINT
Observe the user manuals of all connected
devices!
Symbols on the Nameplate
Symbol Description
Refer to the user manual!
The product bears the CE-mark.
Manufacturer and date of manufacture
Reference number
Serial number
Separate collection for electrical
and electronic equipment!
(refer also to the section "Disposal of the Product")
For a description of additional symbols, if
applicable, please refer to the equipment
description.
Figure 3: Definition of the patient environment
12 D596.131.00/05 en
1 Application
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Application
Operating Manual
1.1 Quick Start (Workflow)
CAUTION
Electricity is a source of risk, particularly when
the product is operated inappropriately.
Shock Hazard! Equipment Damage!
Do not open the detector.
CAUTION
Improper handling.
Erroneous Measurements! Malfunction!
Before switching on the connected devices,
check that all plugs are properly connected.
NOTICE
To avoid equipment damage, observe the
information about electrometer connection and
setup and about measurements provided in the
user manual of the electrometers used.
HINT
PTW recommends transferring all components
of the measuring system from the storage room
to the treatment room well in advance of the
measurement to allow the temperature in the
devices to adapt to the ambient temperature. If
the difference in temperature is high, the measurement quality may be impaired (particularly
when measurements are performed in phantoms).
D596.131.00/05 en 13
Connect the electrometer and switch it on.
•
Perform all necessary adjustments at the elec-
•
trometer. Verify that the high voltage is correctly adjusted.
Connect the detector.
•
Allow for a stabilization time of 15 minutes
•
before starting the measurement.
For absolute dosimetry: Determine the correc-
•
tion factor for the air density correction. If possible, set the correction factor at the electrometer or note it down for the correction of the
measured value.
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Application
1.2 General Application Information
The detectors are intended to be used with PTW
precision electrometers according to IEC 60731.
The detectors are used for dose and dose
rate measurement for the measuring quantities
'absorbed dose to water' and 'air kerma'. They are
applied in absolute and relative dosimetry or for
calibration measurements in air or in solid state
phantoms.
Only the Farmer chamber, type 30013, is waterproof. These detectors are intended to be used in
a water phantom.
Pre-irradiate the detector.
•
Check the leakage current. The leakage cur-
•
rent should be low and stable.
Perform a zero adjustment.
•
Perform the measurement.
•
The black line on one side of the chamber stem
should face the radiation source during use.
NOTICE
To avoid damage to the detector, observe the
following points:
The wall around the sensitive volume is very
delicate and can easily be damaged.
Do not touch the wall with your hands or with
tools.
During storage, protect the chamber wall with
the build-up cap.
Handle the detectors with extreme care when
inserting them into adapters (for phantoms or
check devices) or removing them.
14 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Application
Operate the detectors only in the rated ranges
of use indicated in section 3 "Technical Specifi-
cations". Other operating conditions may lead to
incorrect results.
HINT
Using the detectors with other electrometers
or within other rated ranges of use is the sole
responsibility of the user.
WARNING
High voltage is a source of risk.
Bodily Injury!
The combination of different connection systems to connect the detectors requires special
precaution. Connect high voltage only via an
active current limitation (I
When the detectors are properly connected, high
voltage is not applied to any of the exposed components.
< 0.5 mA).
max
Air Density Correction
The detectors are vented and require air density
correction. The correction factor kTP for air density
correction is calculated according to the following
formula.
T temperature in sensitive volume [°C]
P atmospheric pressure at measuring
site [hPa]
T
calibration temperature 20 °C or 22 °C
0
P
atmospheric pressure for calibration
0
1013.25 hPa
Check the aeration for proper functioning by
comparison with other chambers or by using a
radioactive check device.
Connection cables with an overall length of up to
100 m can be used between the detectors and the
measuring device.
For measurements with
137
Cs, 60Co or higher energies in air, always use the detectors with their
build-up caps. Performing the measurements with
these radiation qualities without build-up caps will
lead to incorrect results.
D596.131.00/05 en 15
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Application
Application in Water
The detectors are not waterproof.
NOTICE
Do not use the detectors in water. Using them
in water is not intended and may cause damage to the detectors and to the electrometer
and may lead to dangerous short-circuits.
The Farmer chamber, type 30013, is waterproof.
NOTICE
To avoid damage to the detector, observe the
following points:
The detectors are allowed to remain immersed
in water without interruption for a maximum of
12 hours.
After use, remove the detectors from the water
and dry them thoroughly.
1.3 Special Application Considerations
NOTICE
Use only accessories, such as positioner,
adapter, chamber plate, or check device,
approved by PTW for the different applications; refer to section 5 "Accessories and Spare
Parts".
Application with the Radioactive Check
Device
Proceed as follows:
Unscrew the build-up cap from the detector.
•
Introduce the detector holder T48002.3.003
•
into the chamber well of the check device all
the way.
When attaching the build-up cap, make sure
that there is no water between the detector and
the cap.
Guard Ring
The guard ring of the detector is designed up to
the sensitive volume. The potential of the guard
ring is equivalent to the potential of the central
electrode. When the detector is properly connected, high voltage is not applied to any of the
exposed components.
Carefully introduce the detector into the holder
•
all the way. Line up the marks on the chamber
stem and on the holder.
When the detectors are not in use: Screw the
•
build-up cap onto the detector housing.
16 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Application
Application in the Slab Phantom
Special chamber plates are available for measurements with the detector. Mount the detector
as follows:
Unscrew the build-up cap from the detector.
•
Carefully insert the detector into the chamber
•
plate. The mark on the chamber stem should
face the radiation source during use.
When the detectors are not in use: Screw the
•
build-up cap onto the detector housing.
D596.131.00/05 en 17
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Measuring Ranges
2 Measuring Ranges
When used in combination with the PTW electrometers, the typical measuring ranges of the detectors are
as given below.
The resolution of the digital display is at least 0.5% of the indicated measuring ranges.
The upper measuring range limit of the dose rate in consideration of the recombination losses is given in
section 3 "Technical Specifications".
Measuring ranges for use with a TANDEM
Measuring ranges
Dose rate
LOW
MEDIUM
HIGH
15 mGy/min - 3 Gy/min
150 mGy/min - 30 Gy/min
1.5 Gy/min - 300 Gy/min
Measuring ranges for use with a UNIDOS
Measuring ranges
Dose (charge)
LOW
HIGH
Dose (integrated value)
LOW
MEDIUM
HIGH
Dose rate
LOW
MEDIUM
HIGH
100 µGy/min - 600 Gy/min
5 mGy/min - 30 kGy/min
500 m/min - 3.3 MGy/min
600 µGy/min - 600 mGy/min
30 mGy/min - 30 Gy/min
100 µGy - 11 mGy
5 mGy - 1.1 Gy
3 Gy/min - 3 kGy/min
18 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Measuring Ranges
Measuring ranges for use with a UNIDOS E
Measuring ranges
Dose
LOW
MEDIUM
100 µGy - 325 Gy
10 mGy - 33 kGy
HIGH
Dose rate
LOW
MEDIUM
HIGH
600 µGy/min - 300 mGy/min
60 mGy/min - 30 Gy/min
6 Gy/min - 3 kGy/min
1 Gy - 3.3 MGy
Measuring ranges for use with a UNIDOS
Measuring ranges
Dose
LOW
100 µGy - 45 kGy
MEDIUM
HIGH
500 mGy - 450 MGy
Dose rate
LOW
MEDIUM
HIGH
600 µGy/min - 750 mGy/min
30 mGy/min - 75 Gy/min
3 Gy/min - 7.5 kGy/min
webline
5 mGy - 4.5 MGy
D596.131.00/05 en 19
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Operating Manual - Measuring Ranges
20 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Technical Manual
3 Technical Specifications
Only values with specified tolerances or limits are guaranteed. Values without tolerances are for informational purposes only.
3.1 Farmer Chambers, Types 30010 and 30013
Device designation Farmer chambers
ionization chambers, types 30010, 30013
Manufacturer PTW-Freiburg
Application standard chambers for absolute and relative dosimetry in combination
with precision electrometers according to IEC 60731
Particular design characteristics
Measuring quantities air kerma and air kerma rate
Radiation quality photons, electrons, protons
Nominal sensitive volume 0.6 cm³
Effective point of measurement (reference point)
– shell chamber (thimble chamber)
– vented
– type 30010: not waterproof
– type 30013: waterproof
– guard ring
absorbed dose to water and absorbed dose rate to water
exposure and exposure rate
equivalent dose and equivalent dose rate
on detector axis, 13 mm behind tip
Reference direction of incidence
D596.131.00/05 en 21
radial
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Device designation Farmer chambers
ionization chambers, types 30010, 30013
Dimensions refer to Figure 4 and Figure 5
Response 20 nC/Gy
Chamber voltage nominal +400 V
maximal ±500 V
Leakage current ≤ ±4 fA
Cable leakage ≤ 1 pC/(Gy∙cm)
Cable length T30010: 1 m
T30013: 1.3 m
min. bending radius 20 mm (static)
min. bending radius 50 mm (for up to a maximum of 50 repetitions)
Maximum dose rate during
continuous radiation
99.0 % saturation
10 Gy/s
99.5% saturation
5 Gy/s
(at nominal voltage)
Maximum dose per radiation
pulse (at nominal voltage)
Ion collection time (at nomi-
99.0 % saturation
0.91 mGy
140 µs
99.5 % saturation
0.46 mGy
nal voltage)
Polarity effect ≤ ±0.5 % at 60Co
Directional response ≤ ±0.5 % for rotation around the detector axis
≤ ±0.5 % for tilting by ±5° perpendicular to the detector axis
Energy response ≤ ±2 % (70 ... 280) kV, reference 200 kV
≤ ±4 % (200 kV ... 60Co) reference 60Co
Transient periods for
temperature equilibrium
pressure equilibrium
(2 ... 3) min/K
≤ 10 s
Pre-irradiation none
Stabilization time The response after 15 minutes and 2 hours differs by less than ±0.5 %
from the value after 1 hour.
Post irradiation leakage signal drops to < 0.5 % within 5 s after irradiation
Stability long-term stability: ≤ ±0.5 % per year
dose stability: ≤ ±1 % per 10 kGy 60Co
22 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Device designation Farmer chambers
ionization chambers, types 30010, 30013
Wall material 0.335 mm PMMA + 0.09 mm graphite
Area density total 56.5 mg/cm²
Electrode material Al Ø = 1.1 mm
Build-up cap 4.55 mm PMMA
Rated range of use
Chamber voltage
Energy
±(100 ... 400) V
photons (30 kV ... 50 MV)
electrons (10 ... 45) MeV
protons (50 ... 270) MeV
Field size
Temperature
Relative humidity
Atmospheric pressure
Maximum operating alti-
5 cm x 5 cm ... 40 cm x 40 cm (square field size)
(10 ... 40) °C / (50 … 104) °F
(10 ... 80) %, no condensation (max. 20 g/m³ absolute humidity)
(700 ... 1060) hPa
3000 m above sea level
tude
Environmental conditions for
transport and storage
Temperature
Relative humidity
Atmospheric pressure
(-20 ... +60) °C / (4 … 140) °F
(10 ... 85) %, no condensation (max. 20 g/m³ absolute humidity)
(600 ... 1200) hPa
Maximum dwell in water type 30013: 12h
Connecting systems PTW-M, BNT, TNC
L (only for type 30013)
D596.131.00/05 en 23
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Figure 4: Drawing of the Farmer chamber type 30010 (dimensions in mm)
Figure 5: Drawing of the Farmer chamber type 30013 (dimensions in mm)
24 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
3.2 Farmer Chambers, Types 30011 and 30012
Device designation Farmer chambers
ionization chambers, types 30011, 30012
Manufacturer PTW-Freiburg
Application standard chambers for the absolute and relative dosimetry in combi-
nation with precision electrometers according to IEC 60731
Particular design characteristics
Measuring quantities air kerma and air kerma rate
Radiation quality photons, electrons, protons
Nominal sensitive volume 0.6 cm³
Effective point of measurement (reference point)
Reference direction of incidence
– shell chamber (thimble chamber)
– vented
– not waterproof
– guard ring
absorbed dose to water and absorbed dose rate to water
exposure and exposure rate
equivalent dose and equivalent dose rate
on detector axis, 13 mm behind tip
radial
D596.131.00/05 en 25
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Device designation Farmer chambers
ionization chambers, types 30011, 30012
Dimensions refer to Figure 6 and Figure 7
Response 20 nC/Gy
Chamber voltage nominal +400 V
maximal ±500 V
Leakage current ≤ ±4 fA
Cable leakage ≤ 1 pC/(Gy∙cm)
Cable length 1 m
min. bending radius 20 mm (static)
min. bending radius 50 mm (for up to a maximum of 50 repetitions)
Maximum dose rate during
continuous radiation
99.0 % saturation
10 Gy/s
99.5 % saturation
5 Gy/s
(at nominal voltage)
Maximum dose per radiation
pulse (at nominal voltage)
Ion collection time (at nomi-
99.0 % saturation
0.91 mGy
140 µs
99.5 % saturation
0.46 mGy
nal voltage)
Polarity effect ≤ ±0.5 % at 60Co
Directional response ≤ ±0.5 % for rotation around the detector axis
≤ ±0,5 % for tilting by ±5° perpendicular to the detector axis
Energy response T30011: ≤ ±12 % (280 kV ... 60Co) reference 60Co
T30012: ≤ ±2 % (70 ... 280) kV, reference 200 kV;
≤ ±4 % (200 kV ... 60Co) reference 60Co
Transient periods for
temperature equilibrium
pressure equilibrium
(2 ... 3) min/K
≤ 10 s
Pre-irradiation none
Stabilization time The response after 15 minutes and 2 hours differs by less than ±0.5 %
from the value after 1 hour.
Post irradiation leakage signal drops to < 0.5 % within 5 s after irradiation
Stability long-term stability: ≤ ±0.5 % per year
dose stability: ≤ ±1 % per 10 kGy 60Co
26 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Device designation Farmer chambers
ionization chambers, types 30011, 30012
Wall material 0.425 mm graphite
Area density total 79 mg/cm²
Electrode material T30011: graphite Ø = 1.0 mm
T30012: Al Ø = 1.1 mm
Build-up cap 4.55 mm PMMA
Rated range of use
Chamber voltage
Energy
±(100 ... 400) V
photons T30011:
T30012:
electrons (10 ... 45) MeV
protons (50 ... 270) MeV
Field size
Temperature
Relative humidity
Atmospheric pressure
Maximum operating alti-
5 cm x 5 cm ... 40 cm x 40 cm (square field size)
(10 ... 40) °C / (50 … 104) °F
(10 ... 80) %, no condensation (max. 20 g/m³ absolute humidity)
(700 ... 1060) hPa
3000 m above sea level
tude
Environmental conditions for
transport and storage
Temperature
Relative humidity
Atmospheric pressure
(-20 ... +60) °C / (4 … 140) °F
(10 ... 85) %, no condensation (max. 20 g/m³ absolute humidity)
(600 ... 1200) hPa
Connecting systems PTW-M, BNT, TNC
(140 kV ... 50 MV)
(60 kV ... 50 MV)
D596.131.00/05 en 27
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Technical Specifications
Figure 6: Drawing of the Farmer chamber type 30011 (dimensions in mm)
Figure 7: Drawing of the Farmer chamber type 30012 (dimensions in mm)
28 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual
4 Electromagnetic Compatibility according to IEC 60601-1-2
The following statements apply to the Farmer
chambers types 30010, 30011, 30012, and
30013.
The Farmer chambers will be referred to as product in these statements.
WARNING
Magnetic and electrical fields are capable of
interfering with the proper performance of the
product.
Product Failure!
WARNING
Magnetic and electrical fields are capable of
interfering with the proper performance of the
product.
Product Failure!
Do not use cables longer than specified. This
Do not use the product in the immediate vicinity or placed on top of or below other equipment. However, if the application requires an
arrangement of devices as described above,
the product should be monitored in order to
ensure its proper functioning in the specific
arrangement.
might impair the electromagnetic compatibility
characteristics of the product.
Guidance and Manufacturer’s Declaration – Electromagnetic Emissions
The product is intended for use in the electromagnetic environment specified below. The customer or the
user of the product should assure that it is used in such an environment.
Emissions test Compliance Electromagnetic environment – guidance
RF emissions
IEC/CISPR 11
Group 1 The product uses RF energy only for its internal func-
tion. Therefore, its RF emissions are very low and are
not likely to cause any interference in nearby electronic equipment.
RF emissions
IEC/CISPR 11
Harmonic emissions
IEC 61000-3-2
Voltage fluctuations/flicker
Class B
not applicable
not applicable
The product is suitable for use in all establishments,
including domestic establishments and those directly
connected to the public low-voltage power supply network that supplies buildings used for domestic pur-
1)
poses.
emissions IEC 61000-3-3
1)
The product fulfills the requirements of IEC/CISPR 11 Class B. However, it is not intended for use in domestic
establishments.
D596.131.00/05 en 29
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual
Guidance and Manufacturer’s Declaration – Electromagnetic Immunity
The product is intended for use in the electromagnetic environment specified below. The customer or the
user of the product should assure that it is used in such an environment.
Immunity
tests
Electrostatic
discharge (ESD)
IEC 61000-4-2
Electrical fast
transient/burst
IEC 61000-4-4
Surges
IEC 61000-4-5
Voltage dips, short
interruptions and
voltage variations on
power supply input
lines
IEC 61000-4-11
IEC 60601
test level
± 6 kV
contact
± 8 kV
air
± 2 kV
for power supply
lines
± 1 kV
for input/output lines
± 1 kV
line(s) to line(s)
± 2 kV
line(s) to earth
< 5 % U
T
(> 95 % dip in UT) for
½ cycle
40 % U
T
(60 % dip in UT) for
5 cycles
70 % U
T
(30 % dip in UT) for
25 cycles
Compliance
level
Electromagnetic environment –
guidance
not applicable Floors should be wood, concrete or
ceramic tile. If floors are covered with
synthetic material, the relative humidity should be at least 30 %.
not applicable
Mains power quality should be that of
a typical commercial or hospital environment.
± 1 kV
for input/output lines
not applicable Mains power quality should be that of
a typical commercial or hospital environment.
not applicable Mains power quality should be that of
a typical commercial or hospital environment. If the user of the product
requires continued operation during
power mains interruptions, it is recommended that the product be powered from an uninterruptible power
supply or a battery.
< 5 % U
T
(> 95 % dip in UT) for
5 s
30 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual
Guidance and Manufacturer’s Declaration – Electromagnetic Immunity
Immunity
tests
Power frequency
(50/60 Hz)
magnetic field
IEC 61000-4-8
IEC 60601
test level
Compliance
level
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.
Electromagnetic environment –
guidance
D596.131.00/05 en 31
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual
Guidance and Manufacturer’s Declaration – Electromagnetic Immunity
The product is intended for use in the electromagnetic environment specified below. The customer or the
user of the product should assure that it is used in such an environment.
Immunity
tests
Conducted RF
IEC 61000-4-6
Radiated RF
IEC 61000-4-3
IEC 60601
test level
3 V
rms
150 kHz to
80 MHz
3 V/m
80 MHz to
2.5 GHz
Compliance
level
U1 = 3 V
E1 = 3 V/m
Electromagnetic environment –
guidance
Portable and mobile RF communications equipment should be used no closer to any part of the
product, including cables, than the recommended
separation distance calculated from the equation
applicable to the frequency of the transmitter.
Recommended separation distance
d = (3.5 / U1) √P = 1.2 √P
d = (3.5 / E1) √P = 1.2 √P
80 MHz to 800 MHz
d = (7 / E1) √P = 2.3 √P
800 MHz to 2.5 GHz
where P is the maximum output power rating of the
transmitter in watts (W) according to the transmitter manufacturer and d is the recommended sepa-
ration distance in meters (m).
Field strengths from fixed RF transmitters, as
determined by an electromagnetic site survey a),
should be less than the compliance level in each
frequency range.
b)
Interference may occur in the vicinity of equipment
marked with the following symbol:
NOTE 1: At 80 MHz and 800 MHz, the higher frequency range applies.
NOTE 2: These guidelines may not apply in all situations. Electromagnetic propagation is affected by
absorption and reflection from structures, objects and people.
32 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual
Guidance and Manufacturer’s Declaration – Electromagnetic Immunity
a)
Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones
and land mobile radios, amateur radio, 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 product is used exceeds the applicable RF compliance level above, the
product should be observed to verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as re-orienting or relocating the product.
b)
Over the frequency range 150 kHz to 80 MHz, field strengths should be less than [U1] V/m = 3 V/m.
D596.131.00/05 en 33
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual
Recommended separation distances between portable and
mobile RF communications equipment and the product
The product is intended for use in an electromagnetic environment in which radiated RF disturbances
are controlled. The customer or the user of the product can help prevent electromagnetic interference by
maintaining a minimum distance between portable and mobile RF communications equipment (transmitters) and the product as recommended below, according to the maximum output power of the communications equipment.
Rated maximum
output power
Separation distance according to frequency of transmitter
m
of transmitter
W
150 kHz to 80 MHz
d = (3.5 / U1) √P = 1.2 √P
80 MHz to 800 MHz
d = (3.5 / E1) √P = 1.2 √P
800 MHz to 2.5 GHz
d = (7 / E1) √P = 2.3 √P
0.01 0.12 0.12 0.23
0.1 0.38 0.38 0.73
1 1.2 1.2 2.3
10 3.8 3.8 7.3
100 12 12 23
For transmitters rated at a maximum output power not listed above, the recommended separation distance
d in meters (m) can be estimated 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 manu-
facturer.
NOTE 1: At 80 MHz and 800 MHz, the higher frequency range applies.
NOTE 2: These guidelines may not apply in all situations. Electromagnetic propagation is affected by
absorption and reflection from structures, objects and people.
34 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Accessories and Spare Parts
5 Accessories and Spare Parts
Radioactive check device 90Sr T48012
Holder for radioactive check device T48002.3.003
TRUFIX precision mounting system for positioning of detectors in TBA systems
TRUFIX precision mounting system, holder for Farmer chamber T30013 T4316/U381
PMMA chamber plate 30 cm x 30 cm T2967/29
PMMA chamber plate 40 cm x 40 cm T40005.3.021
RW3 chamber plate 30 cm x 30 cm T29672/U19
RW3 chamber plate 40 cm x 40 cm T40006.1.015
L981150
D596.131.00/05 en 35
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Technical Manual - Accessories and Spare Parts
36 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Service Manual - Cleaning
Service Manual
WARNING
Improper execution of service tasks.
Hazards to Persons! Equipment Damage!
Ensure that the service tasks described below
are only performed by specialized staff.
In addition, ensure that all other service tasks
are only performed by PTW-Freiburg or by a
person authorized by PTW-Freiburg.
6 Cleaning
General Information on Cleaning
DANGER
Liquids have entered the product.
Shock Hazard! Erroneous Measurements!
Have the product inspected by service personnel before putting it into service again.
NOTICE
To avoid surface damage, do not use disinfectants on a phenol base or peroxide compounds
to disinfect the surface.
The product cannot be sterilized or completely
disinfected.
The outer shell of the detectors is made of plastic.
To avoid impairing the equipment functions, the
detectors must not be treated with or come in contact with grease, oil, alcohol, or substances containing solvents.
Cleaning agents and solvents contained in disinfectants (alcohols) have proved to be particularly
harmful.
D596.131.00/05 en 37
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Service Manual - Cleaning
Clean the product simply by wiping it down with
a dry or slightly moistened cloth. Use water or a
mild soap solution.
Alternatively, you can use a common disinfection
agent for medical instruments which is specified
in the list of disinfectants of your national hygiene
institute (e.g., VAH in Germany). If your country
does not provide such a list, we recommend either
a solution on an aldehyde base or a solution with
a quaternary ammonium compound.
Detectors and Connection Cables
Disconnect the detectors from the measuring
•
device (always pull on the connector, not on
the cable!).
Only wipe the detectors and the connection
•
cables down. Do not immerse the detectors or
connection cables in liquid. Liquids must not
be allowed to penetrate. Do not spray anything
onto the detectors and connectors. All contacts must remain clean and dry.
Connectors
NOTICE
To avoid equipment damage, do not immerse
the connectors in liquids. Liquids must not be
allowed to enter the connectors.
The connectors must always be clean. Use a soft
brush to remove dust (do not blow onto the connector!).
Non-use
When not in use, the product should be stored in
its case for protection.
The connector of the detector should be protected
against humidity and dust with the supplied cap.
The chamber volume must be protected against
mechanical damage by means of the build-up
cap.
38 D596.131.00/05 en
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Service Manual - Preventive Maintenance
7 Preventive Maintenance
Below, you will find a list of the maintenance measures and inspections necessary for the product.
Check before each use
Before each use, visually inspect the product
•
and cables for signs of mechanical damage.
Conduct a functional control. For this, you can
•
use a radioactive check device of PTW (refer
to section 5 "Accessories and Spare Parts").
For further information on the functional control
please refer to the user manual of the radioactive check device.
If damage or malfunctions are identified, the
•
product must be repaired before it is used
again.
Check the leakage current after having con-
•
nected the detector.
The detectors are designed for operation in a
limited temperature and humidity range (refer
to section 3 "Technical Specifications"). If a
detector has been subjected to higher humidity this can result in increased leakage current.
Such a detector can normally be restored to
normal functionality by heating to 40 °C for at
least 8 hours at low humidity.
Safety Inspections
Only regularly inspected products are fail-safe. To
preserve the functional security and operational
safety, a safety inspection is to be executed at
regular intervals according to the national regulations.
These inspections must only be performed by
independent persons with adequate training and
experience.
It is recommended to execute the safety inspections every 2 years.
Technical Inspection of the Measuring
System
The product must be inspected at regular intervals according to the national regulations. It is recommended to perform technical inspections of the
measuring system every 2 years at PTW-Freiburg
or a qualified calibration laboratory.
Inspections must also be performed after repairs
or after each influence that may have changed the
behavior of the product.
Repair
Repairs may only be carried out by PTW-Freiburg
or by persons/companies authorized by PTWFreiburg.
D596.131.00/05 en 39
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Service Manual - Disposal of the Product
Calibration
The exact calibration factor and supplementary
data are included in the calibration certificate.
For use at high energies (above 1.3 MeV correction factors according to the relevant national
or international dosimetry protocols must be
observed (e.g., IAEA TRS 277 or TRS 398).
The product should be recalibrated at a dose rate
typical for the application. Calibrations should be
done at 60Co.
It is recommended to have the product calibrated
every 2 years at PTW-Freiburg or by specially
trained staff on site (when using a radioactive
check device and performing regular check measurements: 6 years).
8 Disposal of the Product
The typical lifetime of the product is approx.
10 years, if used normally.
At the end of the product lifetime, the components
of the product must be disposed of in compliance
with the applicable waste control regulations. The
different materials must be separated and recycled as appropriate.
The electronic components must be recycled
according to the local regulations.
The product does not contain hazardous materials.
40 D596.131.00/05 en
Literature
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Literature
[1] Council Directive 93/42/EEC concerning medical devices
(Medical Device Directive - MDD)
[2] Council Directive 97/43/EURATOM on health protection
of individuals against the dangers of ionizing radiation in
relation to medical exposure
[3] IEC 60731
Medical electrical equipment Dosimeters with ionization chambers as used in radiotherapy
[4] IEC 61010-1
Safety requirements for electrical equipment for measurement, control and laboratory use Part 1: General requirement
[5] IEC 60601-1-2
Medical electrical equipment Part 1-2: General requirements for basic safety and
essential performance Collateral Standard: Electromagnetic compatibility Requirements and tests
[6] IEC/CISPR 11
Industrial, scientific and medical equipment Radio-frequency disturbance characteristics - Limits and
methods of measurement
[7] IEC 61000-3-2
Electromagnetic compatibility (EMC) Part 3-2: Limits Limits for harmonic current emissions (equipment input
current ≤ 16 A per phase)
[8] IEC 61000-3-3
Electromagnetic compatibility (EMC) Part 3-3: Limits Limitation of voltage changes, voltage fluctuations and
flicker in public low-voltage supply systems, for equipment with rated current ≤ 16 A per phase and not subject
to conditional connection
[9] IEC 61000-4-2
Electromagnetic compatibility (EMC) Part 4-2: Testing and measurement techniques Electrostatic discharge immunity test
[10] IEC 61000-4-3
Electromagnetic compatibility (EMC) Part 4-3: Testing and measurement techniques Radiated, radio-frequency, electromagnetic field immunity test
[11] IEC 61000-4-4
Electromagnetic compatibility (EMC) Part 4-4: Testing and measurement techniques Electrical fast transient/burst immunity test
[12] IEC 61000-4-5
Electromagnetic compatibility (EMC) Part 4-5: Testing and measurement techniques Surge immunity test
[13] IEC 61000-4-6
Electromagnetic compatibility (EMC) Part 4-6: Testing and measurement techniques Immunity to conducted disturbances, induced by radiofrequency fields
[14] IEC 61000-4-8
Electromagnetic compatibility (EMC) Part 4-8: Testing and measurement techniques Power frequency magnetic field immunity test
[15] IEC 61000-4-11
Electromagnetic compatibility (EMC) Part 4-11: Testing and measurement techniques Voltage dips, short interruptions and voltage variations
immunity tests
D596.131.00/05 en 41
Index
Farmer Chamber
Ionization Chamber
Type 30010, 30011, 30012, 30013
Index
A
Accessories............................................................. 35
Air density correction............................................... 15
Application............................................................... 13
Application considerations, special.......................... 16
Application information, general.............................. 14
Application in water................................................. 16
B
Build-up caps........................................................... 15
C
Calibration................................................................ 40
Chamber wall........................................................... 14
Cleaning................................................................... 37
D
Dimensions Farmer chamber type 30010................ 23
Dimensions Farmer chamber type 30011................ 27
Dimensions Farmer chamber type 30012................ 28
Dimensions Farmer chamber type 30013................ 24
Disposal................................................................... 40
Q
Quick start............................................................... 13
R
Radioactive check device........................................ 16
Repair...................................................................... 39
S
Safety information...................................................... 7
Safety inspections................................................... 39
Slab phantom.......................................................... 17
Spare parts.............................................................. 35
Symbols................................................................... 12
T
Technical inspections of the measuring system....... 39
Technical specifications............................... 21, 21, 25
W
Workflow.................................................................. 13
E
Electromagnetic compatibility.................................. 29
G
General information................................................... 2
Guard....................................................................... 16
Guard ring................................................................ 16
H
High voltage............................................................. 15
I
Intended use.............................................................. 6
L
List of figures............................................................. 5
Literature.................................................................. 41
M
Maintenance............................................................ 39
Measuring ranges.................................................... 18
42 D596.131.00/05 en
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