LUDLUM ION CHAMBER
MODEL 9-4 USERS MANUAL
June 2018
Serial Number 265751 and Succeeding
Serial Numbers
LUDLUM ION CHAMBER
MODEL 9-4 USERS MANUAL
June 2018
Serial Number 265751 and Succeeding
Serial Numbers
Ludlum Measurements, Inc. Copyright© 2013.
STATEMENT OF WARRANTY
Ludlum Measurements, Inc. warrants the products covered in this manual to be free of
defects due to workmanship, material, and design for a period of twelve months from
the date of delivery. The calibration of a product is warranted to be within its
specified accuracy limits at the time of shipment. In the event of instrument failure,
notify Ludlum Measurements to determine if repair, recalibration, or replacement is
required.
This warranty excludes the replacement of photomultiplier tubes, G-M and
proportional tubes, and scintillation crystals which are broken due to excessive
physical abuse or used for purposes other than intended.
There are no warranties, express or implied, including without limitation any implied
warranty of merchantability or fitness, which extend beyond the description of the
face there of. If the product does not perform as warranted herein, purchaser’s sole
remedy shall be repair or replacement, at the option of Ludlum Measurements. In no
event will Ludlum Measurements be liable for damages, lost revenue, lost wages, or
any other incidental or consequential damages, arising from the purchase, use, or
inability to use product.
RETURN OF GOODS TO MANUFACTURER
If equipment needs to be returned to Ludlum Measurements, Inc. for repair or calibration, please
send to the address below. All shipments should include documentation containing return shipping
address, customer name, telephone number, description of service requested, and all other necessary
information. Your cooperation will expedite the return of your equipment.
LUDLUM MEASUREMENTS, INC.
ATTN: REPAIR DEPARTMENT
501 OAK STREET
SWEETWATER, TX 79556
800-622-0828 325-235-5494
FAX 325-235-4672
Ludlum Measurements, Inc. June 2018
Safety Precautions
In the interest of safety, this manual contains many notes, cautions, and warnings that the user
should follow to protect both the user and the instrument from harm.
Warning – The operator or responsible body is warned that failure to follow the specified
operating, handling, or maintenance procedures may result in death, serious injury, or a longterm health hazard.
Caution - The operator or responsible body is cautioned that the protection provided by the
equipment may be impaired if the equipment is used or handled in a manner not specified by
Ludlum Measurements, Inc.
Note – The operator or responsible body should give special attention to the information
provided, as failure to do so may result in damage to the instrument or instrument failure.
GENERAL SAFETY PRECAUTIONS
The following general safety precautions apply to the operator of the instrument during all phases of
operation. These precautions should be followed or else the instrument may no longer provide the
necessary protection for which the instrument was intended.
DO NOT REMOVE CHASSIS FROM CAN WITH BATTERIES INSTALLED
Normal operation of the instrument should always be performed with the instrument chassis
attached to a can. The operator is strongly cautioned to take the following precautions to avoid
contact with internal hazardous live parts should it be determined that the chassis needs to be
separated from the can:
1. Turn the instrument power off and remove the batteries.
2. Allow the instrument to sit for one minute before accessing internal components.
Ludlum Measurements, Inc. i June 2018
DO NOT SUBMERGE IN WATER
The instrument meets the standards as specified by ANSI N42.17C for moisture exposure; however,
the instrument is not waterproof and should never be submersed in water.
WARNINGS APPLICABLE TO HAZARDOUS MATERIALS
Visual images are used in this manual to convey the possible hazard associated with the operation,
handling, or maintenance of the instrument. The following definitions are provided to describe these
hazards; however, Ludlum Measurements cannot make any guarantees to the extent of the hazard
posed.
CHEMICAL – this is an indication that handling the material may cause burns or
irritation to the skin.
ELECTRICAL SHOCK – unless the necessary precautions are taken, this is an
indication that physical contact with the internal components of the instrument may
result in electrical shock.
HOT AREA – this is an indication that the component or components may be hot
resulting in burns to the skin.
POISON – this is an indication that the contents may be hazardous to your health if
consumed.
INSTRUMENT MARKINGS
The Model 9-4 Ion Chamber is marked with the following symbols:
Crossed-out wheelie bin – this symbol notifies the consumer that the product is not to
be mixed with unsorted municipal waste when discarding; each material must be
separated. The symbol is placed on the battery compartment lid.
The “CE” mark is used to identify this instrument as being acceptable for use within the
European Union.
Ludlum Measurements, Inc. ii June 2018
TABLE OF CONTENTS
INTRODUCTION ...................................................................................................................................................... 1
IDENTIFICATION OF CONTROLS AND FUNCTIONS ................................................................................................... 2
GETTING STARTED .................................................................................................................................................. 3
UNPACKING AND REPACKING .................................................................................................................................. 3
INSTRUMENT CONFIGURATION ................................................................................................................................. 3
BATTERY INSTALLATION ......................................................................................................................................... 4
BATTERY TEST ...................................................................................................................................................... 5
OPERATIONAL CHECK ............................................................................................................................................. 5
TECHNICAL THEORY OF OPERATION ....................................................................................................................... 7
CHAMBER .............................................................................................................................................................. 7
CHAMBER WINDOW ................................................................................................................................................. 7
ELECTROMETER ..................................................................................................................................................... 7
RANGE CHANGE ..................................................................................................................................................... 8
RESET ................................................................................................................................................................... 8
OFFSET ADJUSTMENT ............................................................................................................................................. 8
ZERO ADJUST ........................................................................................................................................................ 8
RANGE CALIBRATION .............................................................................................................................................. 9
RANGE CHANGING .................................................................................................................................................. 9
POWER SUPPLIES ................................................................................................................................................. 10
CLEANING AND MAINTENANCE .............................................................................................................................11
PRECAUTIONS ...................................................................................................................................................... 11
MAINTENANCE ..................................................................................................................................................... 11
Recalibration
Storage
Desiccant
........................................................................................................................................................ 11
.................................................................................................................................................................. 12
.............................................................................................................................................................. 12
SPECIFICATIONS .....................................................................................................................................................14
RECYCLING .............................................................................................................................................................17
PARTS LIST .............................................................................................................................................................18
MAIN CIRCUIT BOARD, DRAWING 293 X 711 ........................................................................................................... 19
ELECTROMETER BOARD, DRAWING 293 X 670 ........................................................................................................ 22
DRAWINGS ............................................................................................................................................................23
TABLE OF FIGURES
Figure 1 - Battery Installation and Removal ........................................................................................................................................................................................ 4
Figure 2 - Battery Door Internal Markings .......................................................................................................................................................................................... 5
Figure 3 - Main Board Layout (Front) ......................................................................................................................................................................... Back of manual
Figure 4 - Main Board Layout (Back) .......................................................................................................................................................................... Back of manual
Figure 5 - Main Board Schematic (Page 1) .................................................................................................................................................................. Back of manual
Figure 6 - Main Board Schematic (Page 2) .................................................................................................................................................................. Back of manual
Figure 7 - Main Board Schematic (Page 3) .................................................................................................................................................................. Back of manual
Figure 8 - Main Board Schematic (Page 4) .................................................................................................................................................................. Back of manual
Figure 9 - Electrometer Board Layout (Front) ........................................................................................................................................................... Back of manaul
Figure 10 - Electrometer Board Schematic (Page 1) .................................................................................................................................................. Back of manual
Ludlum Measurements, Inc. iii June 2018
MODEL 9-4 Technical Manual Section 1
Section
1
T
Introduction
he Ludlum Model 9-4 is a five-range ion chamber instrument for
measuring beta-gamma radiation up to 50 R/hr. The chamber wall,
including the instrument case, is 1000 mg/cm². A 1000 mg/cm²
retractable beta shield allows beta measurement with a 7 mg/cm²
window.
The six-position selector switch selects OFF, ×10K, ×1K, ×100, ×10, and ×1
multipliers. The standard meter face has a dial from 0 to 5 mR/hr. Other
features include a LIGHT toggle switch to activate the white LED display
light, a RESET pushbutton, and a ZERO ADJUST knob. All calibration
controls are done digitally using a special calibration kit (part number: 4293-
676) available from Ludlum Measurements. This kit includes a special
instrument can, pressure calibration kit, all necessary cables, and control
software.
The Model 9-4 calibration kit allows the ability to calibrate for temperature
and pressure. Temperature and pressure compensation thus allows the
instrument to measure within 20% of the true value even when the
temperature is varied from -20 to 50 °C (-4 to 122 °F), and within 15%, as
the pressure is varied from 70 kPa to 106 kPa.
The unit is powered by two “D” cell batteries. A fresh set of alkaline
batteries should last more than 400 hours. An internal shunt may be
positioned so that the detector wall voltage is maintained even when the unit
is OFF. Doing so reduces the normal fifteen-minute, cold-start delay.
Ludlum Measurements, Inc. Page 1 June 2018
MODEL 9-4 Technical Manual Section 2
Section
2
Identification of Controls and
Functions
Range Selector Switch: This is a six-position switch marked OFF, ×10K,
×1K, ×100, ×10, and ×1. Turning the range selector switch from OFF to one
of the range multiplier positions (×10K, ×1K, ×100, ×10, and ×1) provides
the operator with an overall range of 0 to 50,000 mR/hr. Multiply the scale
reading by the multiplier to determine the actual scale reading.
BAT TEST: Press this switch to check the battery. The meter should read
within the BAT TEST scale on the meter. The range switch may be in any
position except OFF for the battery test.
LIGHT ON-OFF Toggle Switch: In the ON position this switch energizes the
white LED display lights located in the meter compartment.
ZERO ADJUST: This is a full one-turn control that allows for compensation
of electrometer drift. Press and hold the RESET button for five seconds,
then adjust for a zero reading.
RESET Button: The RESET circuit grounds the chamber and opens the
chamber connection to the electrometer. This action causes a hard upscale
transient on the ×1 and ×10 scales. Hold the RESET down for five seconds
to allow the transient to decay. When the RESET switch is released, the
chamber is reconnected to the electrometer, and a hard downscale transient
will occur. Allow five more seconds for recovery.
Beta Shield (on bottom): This retractable shield allows exposure to beta
radiation with a window thickness of 7 mg/cm². With the slide closed, the
window is 1000 mg/cm². Depress the button on the side of the slide
assembly to release the slide. Release the button to hold the slide open or
closed.
Ludlum Measurements, Inc. Page 2 June 2018
MODEL 9-4 Technical Manual Section 3
Section
3
Getting Started
Unpacking and Repacking
Remove the calibration certificate and place it in a secure location. Remove
the instrument and all accessories and ensure that all items on the packing list
are in the carton.
To return an instrument for calibration or repair, provide sufficient packing
material to prevent damage during shipment and affix appropriate warning
labels to promote careful handling.
Every returned instrument must be accompanied by an Instrument Return
Form, which can be downloaded from the Ludlum website at
www.ludlums.com. Find the form by clicking the “Support” tab and selecting
“Repair and Calibration” from the drop-down menu. Then choose the
appropriate Repair and Calibration division where you will find a link to the
form.
Ludlum Measurements, Inc. Page 3 June 2018
Instrument Configuration
The Model 9-4 has two options for chamber wall voltage. An internal jumper
may be selected to maintain voltage on the chamber wall with the instrument
turned off. This option allows a faster, three-minute settling time when the
instrument is frequently used. If the instrument is infrequently used, it is
recommended that this option not be used because of battery drain.
The instrument is shipped with the chamber wall voltage
maintained when the instrument is turned off.
MODEL 9-4 Technical Manual Section 3
With the continuous wall voltage on and instrument off, battery life is
approximately six months. Without this option, the battery drain is zero with
the instrument OFF; however, a settling time of 15 minutes is required for
the ×1 scale to settle within 0.1 mR/hr.
Battery Installation
Ensure the Model 9-4 range selector switch is in the OFF position. Open the
battery lid by pushing down and turning the quarter-turn thumbscrew
counterclockwise a quarter of a turn. Install two “D” size batteries in the
compartment.
Ludlum Measurements, Inc. Page 4 June 2018
Figure 1 - Battery Installation and Removal
MODEL 9-4 Technical Manual Section 3
Figure 2 - Battery Door Internal Markings
Note the (+) and (-) marks inside the battery holder (see Figure 2 - Battery
Door Internal Markings). Match the battery polarity to these marks. Insert
both batteries to match these marks. Close the battery box lid, then push
down and turn the quarter-turn thumb screw clockwise a quarter of a turn.
The center post of a battery is positive. The batteries are placed in
the battery compartment in opposite directions.
Battery Test
The batteries should be checked each time the instrument is turned on. This
is accomplished simply by pressing the BAT TEST button. Ensure that the
meter needle deflects to the battery test portion of the meter scale. If the
meter does not respond, check to see if the batteries have been correctly
installed. Replace the batteries if necessary.
Operational Check
To assure proper operation of the instrument between calibrations and
periods of non-use, the following instrument operational check should be
performed prior to use. A reference reading with a check source should be
obtained at the time of initial calibration or as soon as possible for use in
confirming proper instrument operation. In each case, ensure a proper
reading on each scale. If the instrument fails to read within 20% of a proper
reading, it should be sent to a calibration facility for recalibration.
Ludlum Measurements, Inc. Page 5 June 2018
MODEL 9-4 Technical Manual Section 3
Turn the instrument range switch to the ×1 position.
As the selector switch moves from the ×100 to ×10 a meter
transient will occur. This transient is caused by an internal range
relay and is normal.
Allow time for the ×1 scale to stabilize.
Press and hold the RESET button. Adjust the ZERO ADJUST knob until
a meter reading of zero is obtained. Release the RESET button.
The RESET circuit grounds the chamber and opens the chamber
connection to the electrometer. This would normally cause a
transient on the ×1 or ×10 scale. The meter needle will, on these
two ranges, display a “countdown” from five to zero when the
RESET is pressed, and also when it is released. On these two
lower ranges the user should hold the RESET down for five
seconds to allow the transient to decay.
Expose the instrument to a check source. Observe that the meter reading
increases as the check source gets closer to the instrument.
The depressions on the side of the instrument housing indicate the
center of the chamber.
Open the beta shield and expose the check source to the center of the
chamber window. The instrument reading should be within 20% of the
check source reference after settling time.
Damage to the metallized polyester window on the back side of
the instrument may result when the slide is open if careful
instrument handling is not practiced. The window is fragile and
may be punctured quite easily.
Ludlum Measurements, Inc. Page 6 June 2018
MODEL 9-4 Technical Manual Section 4
Section
4
Technical Theory of Operation
Chamber
The chamber housing is constructed from acrylic and is coated inside and
outside with carbon. The internal wall is maintained at approximately -90
volts. The external wall is at guard potential (approximately 1.5 volts).
The electrode is connected to the electrometer input and is maintained at
guard potential by the electrometer.
Chamber Window
The chamber window consists of three parts. The beta shield is 1000 mg/cm²
phenolic. One layer of 3.5 mg/cm² aluminized metallized polyester is glued to
the bottom of the can. One layer of 3.5 mg/cm² aluminized metallized
polyester covers the ion chamber, resulting in a window thickness of 7
mg/cm² with the beta slide open and a 1000 mg/cm
slide closed.
2
window with the beta
Electrometer
The electrometer consists of U1, R2, and supporting components. On the ×1
scale, RL1 and RL2 are open. With conduction in the chamber to the
negative wall, pin 8 of U1 goes slightly negative causing pin 4 of U1 to go
positive, drawing current through R2, holding pin 8 of U1 near the guard
voltage (+1.5 volts).
With the chamber exposed to a 5 mR/hr field, the chamber current will be
approximately 70 fA (70 x 10
be 35 mV (0.035 V) relative to the guard voltage. At 50 mR/hr on the x10
range, the output voltage will be 350 mV (0.35 V) relative to the guard
voltage.
-15
amps) and electrometer output voltage will
Ludlum Measurements, Inc. Page 7 June 2018
MODEL 9-4 Technical Manual Section 4
Range Change
When the instrument is switched to the ×100, ×1K, or ×10K range, RL1
is closed, reducing the feedback resistance to approximately 4.2 x 109
ohms. At 500 mR/hr on the x100 range, the chamber current will be
approximately 7 pA (7 x 10
will be approximately 30 mV (0.03 V). Full-scale voltage outputs relative
to the guard voltage for the x1K and x10K are 300 mV (0.3 V) and 3 V
respectively.
-12
amps) and the voltage out at pin 6 of U1
Reset
Relay RL2 allows the chamber to be shorted to guard and the electrometer to
be isolated for input bias current compensation.
Offset Adjustment
The electrometer op amp will have some offset voltage. Internal calibration
control R111 will provide an offset voltage that can be adjusted to null out
the electrometer offset voltage. Place instrument in a field less than 0.1
mR/hr, then select the ×100 scale and adjust R111 for zero meter reading.
Zero Adjust
The primary function of the zero adjust is to control input bias current in the
electrometer. With the RESET (SW1) closed, the reset relay (RL2) opens the
electrometer input and shorts the chamber output to guard. With the
RESET held closed, input bias current is adjusted with the zero control for a
zero meter dial reading.
Allow a five-second recovery period for the meter to settle before
and after using the RESET button on the ×1 and ×10 scales.
Ludlum Measurements, Inc. Page 8 June 2018
MODEL 9-4 Technical Manual Section 4
Range Calibration
Full-scale voltage for the electrometer output, pin 4 of U1 (electrometer
board 5293-711) is approximately +0.03 volts for the ×1 range; 0.3 volts for
the ×10 range; +0.03 volts for the ×100; and +0.3 volts for the ×1K range.
The ×10K range will be somewhat lower than +3 volts due to nonlinear
collection.
On the ×1 scale, the electrometer voltage is coupled through the analog
switch U102A to a series of op amps. U101 provides gain. U100 provides
gain and reduces the output and reference from guard voltage to 0.2 volts.
Voltage output at pin 1, U100 is approximately 2 volts at full scale. Higher
scales follow the same scheme through the analog switches selected by the
range switch.
The output voltage of U100 is connected to microprocessor U110 which
allows calibration, temperature correction, and altitude compensation.
The signal reference voltage is 0.2 volts at the output of DA converter U112,
allowing a below-zero meter reading when adjusting the zero control.
Range Changing
The microprocessor U110 detects the selected range and then selects the
appropriate analog switch (U102A, U102B, or U103A) for the signal.
A calibration constant is then provided by the microprocessor for each range.
In the special case of ×10K scale, the microprocessor also provides a linearity
correction.
Each range may be calibrated by a calibration equipment kit when connected
to P102.
Ludlum Measurements, Inc. Page 9 June 2018
MODEL 9-4 Technical Manual Section 4
Power Supplies
Six voltages are provided for instrument operation.
U108 and associated components generate -90 volts for chamber wall
voltage. The supply will run continually with the instrument off if the jumper
is placed between pins 1 and 2 of JP100. If the operator chooses to have wall
voltage off with the instrument switched off, then the jumper should be
moved to pins 2 and 3 of JP100.
U105 and associated components generate +5 volts for the main board
circuits.
U106 provides regulated +2.5 volt reference.
VR100 provides +4.85 volts for the electrometer.
U107 and associated components provides 1.5 volt guard voltage for the
electrometer.
U104 provides meter reference of 0.2 volts.
Ludlum Measurements, Inc. Page 10 June 2018
MODEL 9-4 Technical Manual Section 5
Section
5
Cleaning and Maintenance
Precautions
Instrument maintenance consists of keeping the instrument clean and
periodically checking the batteries, desiccants, and calibration. The Model 9-4
(excluding chamber window) may be cleaned externally with a damp cloth,
using only water as the wetting agent. Do not immerse the instrument in any
liquid. Observe the following precautions when cleaning or performing
maintenance on the instrument:
1. Turn the instrument OFF and remove the batteries.
2. Allow the instrument to sit for one minute before cleaning the
exterior or accessing any internal components for maintenance.
Accessing internal components for maintenance
increases the risk of electrical shock if these steps are
not followed.
Maintenance
RECALIBRATION
Recalibration should be accomplished after maintenance or adjustments have
been performed on the instrument. Recalibration is not normally required
following instrument cleaning, desiccant servicing, or battery replacement.
Ludlum Measurements, Inc. recommends recalibration at intervals
no greater than one year. Check the appropriate regulations to
determine required recalibration intervals.
Ludlum Measurements, Inc. Page 11 June 2018
MODEL 9-4 Technical Manual Section 5
Ludlum Measurements offers a full-service repair and calibration department.
We not only repair and calibrate our own instruments, but also most other
manufacturers’ instruments. Calibration procedures are available upon request
for customers who choose to calibrate their own instruments.
STORAGE
The batteries may be removed any time the instrument is placed into storage.
Battery leakage may cause corrosion on the battery contacts, which must be
scraped off and/or washed using a paste solution made from baking soda and
water.
Although this instrument will operate at very high ambient
temperatures, battery seal failure may occur at temperatures as low
as 37 °C (100 °F). Should battery seal failure occur, it may result
in corrosion on the battery contacts.
DESICCANT
Remove the instrument can and observe the translucent plastic desiccant box.
If the desiccant is blue, close the can and use the instrument. If the desiccant
is pink, replace with a fresh box. The restraining strap may be loosened by
pressing the center tab toward the strap.
The silica used in the desiccant box may
cause irritation to the skin if handled
directly. Please take the necessary
precautions to avoid long-term physical
contact with the silica. Should handling of the product be required,
avoid rubbing your eyes or placing your hands in or around your
mouth as the silica may also cause an irritation of the digestive
tract. Wash with mild soap and water after handling.
The pink (wet) desiccant may be recycled by placing it in an oven at 55
°C (131 °F) for two hours, or in a microwave on the HI setting for 10
seconds. If water vapor is apparent, wipe off the water and heat for
another 10 seconds. Repeat until the box and desiccant appear dry.
Ludlum Measurements, Inc. Page 12 June 2018
MODEL 9-4 Technical Manual Section 5
Repeat until the box and desiccant appear dry. When fully dried out, the
desiccant will be blue in color.
The desiccant box may be HOT when removed
from the microwave or oven! Please use caution so
as to avoid burning your skin.
If the instrument is stored in an area with high humidity, rapid changes in
temperature should be avoided. A storage cabinet with a light bulb inside is
one means of keeping the instrument in a slightly warmer-than-ambient
temperature environment in order to prevent problems from rapid changes in
temperature and humidity.
Ludlum Measurements, Inc. Page 13 June 2018
MODEL 9-4 Technical Manual Section 6
Section
6
Specifications
0
Linearity: reading within 10% of true value
Range: 0-500 mSv/h (0-50,000 mR/hr)
Chamber:
Chamber Wall Construction: carbon-coated acrylic
Chamber Volume: 220 cm
Window: 7 mg/cm
Window Area: 40 cm
Beta Shield: retractable 1000 mg/cm
Beta Factor: with the instrument exposed to a depleted uranium slab of
234 mrad/hr:
Reading with slide open: 50 mR/hr
Reading with slide closed: 1.2 mR/hr
Thus, Beta Factor = 234 divided by (50 minus 1.2) = 4.8
Energy Response: within 20% of true value from 40 keV to 2 MeV
Magnetic Field Exposure: per ANSI 42-17A, magnetic fields of 800 A/m
cause less than a 15% deviation in instrument response
Multipliers: ×1, ×10, ×100, ×1K, and ×10K selected by a front-panel range
selector switch. Transient meter movement will occur when switching
between the ×10 and ×100 ranges; allow three seconds for the meter to
stabilize upscale, 15 seconds to stabilize downscale.
2
metallized polyester
3
2
(6.2 in2)
(13.4 in3)
2
phenolic slide
Noise: Approximately every three minutes an up-scale “kick” may be noted
on the ×1 scale. This is due to normal cosmic background radiation.
Ludlum Measurements, Inc. Page 14 June 2018
MODEL 9-4 Technical Manual Section 6
Response: approximately five seconds for 90% of final meter deflection on
the ×1 and ×10 scales, and three seconds on the ×100, ×1K, and ×10K scales
Warm-up Time: For the ×1 scale and if the wall voltage option is on with the
instrument off, the scale will settle within 0.1 mR/hr within three minutes. If
the wall voltage option is off, allow 15 minutes for the ×1 scale to settle
within 0.1 mR/hr.
Reset: The RESET circuit grounds the chamber and opens the chamber
connection to the electrometer. This would normally cause a transient on the
×1 or ×10 scale. The meter needle will, on these two ranges, display a
“countdown” from five to zero when the RESET is pressed, and also when
it is released. On these two lower ranges the user should hold the RESET
down for five seconds to allow the transient to decay.
Zero Adjust: a control allowing limited background subtract and also used to
compensate electrometer drift
Battery Check: Batteries are good if the meter needle is above the BAT OK
mark when the BAT TEST pushbutton is pressed. At 2.1 Vdc the meter
needle will drop to the edge of the BAT OK area when the BAT TEST
pushbutton is pressed.
Battery Dependence: Instrument calibration change is less than 5% within
battery check limits on the meter.
Battery Life: approximately 400 hours of normal use without display light;
battery life with instrument off but with wall voltage being maintained is
approximately six months
Construction: cast and drawn aluminum with beige powder coating and
subsurface printed Lexan labels
Dimensions: 23.4 x 8.9 x 21.6 cm (9.2 x 3.5 x 8.5 in.) (H x W x L), including
instrument handle
Humidity Range: 40% to 90% relative humidity maintains reading within
15% of standard conditions (40% RH at 22 °C reading)
Meter: 6.4 cm (2.5 in.) arc, mA, pivot-and-jewel suspension
Meter Dial: BAT TEST, 0-5 mR/hr linear for ×1 through ×10K ranges
Ludlum Measurements, Inc. Page 15 June 2018
MODEL 9-4 Technical Manual Section 6
Pollution: Degree 3 (as defined by IEC 664) (Due to condensation,
conductive pollution or dry nonconductive pollution that becomes
conductive occurs. This is found in industrial environments or
construction sites, considered harsh environments.)
Power: two “D” cell batteries housed in a sealed externally accessible
compartment
Temperature Range: -20 to 50 °C (-4 to 122 °F); temperature
compensation maintains calibration within 20% of 22 °C (72 °F) reading
over the entire temperature range
Weight: 1.9 kg (4.2 lb), including batteries
Ludlum Measurements, Inc. Page 16 June 2018
MODEL 9-4 Technical Manual Section 7
Section
7
L
Recycling
udlum Measurements, Inc. supports the recycling of the electronics
products it produces for the purpose of protecting the environment
and to comply with all regional, national, and international agencies
that promote economically and environmentally sustainable recycling
systems. To this end, Ludlum Measurements, Inc. strives to supply the
consumer of its goods with information regarding reuse and recycling of the
many different types of materials used in its products. With many different
agencies – public and private – involved in this pursuit, it becomes evident
that a myriad of methods can be used in the process of recycling. Therefore,
Ludlum Measurements, Inc. does not suggest one particular method over
another, but simply desires to inform its consumers of the range of recyclable
materials present in its products, so that the user will have flexibility in
following all local and federal laws.
The following types of recyclable materials are present in Ludlum
Measurements, Inc. electronic products, and should be recycled separately.
The list is not all-inclusive, nor does it suggest that all materials are present in
each piece of equipment:
Batteries Glass Aluminum and Stainless Steel
Circuit Boards Plastics Liquid Crystal Display (LCD)
Ludlum Measurements, Inc. products, which have been placed on the market
after August 13, 2005, have been labeled with a symbol recognized
internationally as the “crossed-out wheelie bin.” This symbol notifies the
consumer that the product is not to be mixed with unsorted municipal waste
when discarding; each material must be separated. The symbol will be placed
near the AC receptacle, except for portable equipment where it will be placed
on the battery lid.
The symbol appears as such:
Ludlum Measurements, Inc. Page 17 June 2018
MODEL 9-4 Technical Manual Section 8
Section
8
Model 9-4 Ion
Chamber
Batteries
Handle
Screws
Washers
Shielding
Manual
Calibration
Certificate
Parts List
The following parts are included with the Model 9-4 Five-Range Ion
Chamber (Part Number 48-3739)
Reference Description Part Number
Figures 1 and 4 Model 9-4 Ion Chamber 4293-646
W/O Accessories
Figure 2-1 (x2) Duracell D-Cell 21-9313
Alkaline Batteries
Handle 7363-139
Portable (Grip)
6-32 x 3/8 Flat Button 17-8519
Head Stainless Steel Screws
#6 Stainless Steel Internal 20-9009
Tooth Lock Washer
Model 9-4 Chamber Top 7536-223
Co-Netic Shield
Model 9-4 Chamber Top 7536-224
Netic Shield
Model 9-4 Model 9-4
User’s Manual
Certificate of Calibration FORM C22A
(Valid for 1 Year)
Ludlum Measurements, Inc. Page 18 June 2018
MODEL 9-4 Technical Manual Section 8
Storm Case
Main Circuit Board,
Drawing 293 × 711
CAPACITORS
TRANSISTORS
INTEGRATED
CIRCUITS
The Model 9-4 Five-Range Ion Chamber w/Case (Part Number 48-3701)
includes all the parts included with the 48-3739 as well as the following:
Storm CS-DSI-iM2300 2311063
Medium Black
BOARD Completely Assembled
Main Circuit Board 5293-711
Reference Description Part Number
C100 1uF, 35V 04-5656
C101 0.01uF, 200V 04-5747
C102,C103 0.47uF, 50V 04-5760
C104 10uF, 10V-DT 04-5766
C105 1uF, 35V 04-5656
C106 0.01uF, 200V 04-5725
C107 1uF, 35V 04-5656
C108 0.001uF, 100V 04-5659
C109 68uF, 10V 04-5654
C110 0.1uF, 100V 04-5792
C111 1uF, 50V 04-5708
C112 0.001uF, 100V 04-5659
C113- C116 0.01uF, 200V 04-5765
C118- C119 0.01uF, 200V 04-5765
C120 0.47uF, 100V 04-5776
C121, C122 0.01uF, 200V 04-5765
C123 68uF, 10V 04-5654
C124, C125 0.1uF, 100V 04-5792
C126 0.01uF, 200V 04-5725
C127 0.1uF, 100V 04-5792
C128 1uF, 16V 04-5701
C129 0.01uF, 50V 04-5664
C130 0.47uF, 100V 04-5760
C131, C132 0.47uF, 100V 04-5776
C133 0.1uF, 100V 04-5792
Q100 SI2301BDS-TI 07-6486
Q102 SI2301BDS-TI 07-6486
Q103, Q104 2N7002LT1G 05-5840
U100, U101 LMC7111BIM5X 06-6410
U102, U103 MAX4542ESA 06-6453
U104 LMC7111BIM5X 06-6410
Ludlum Measurements, Inc. Page 19 June 2018
MODEL 9-4 Technical Manual Section 8
DIODES
RESISTORS
Reference Description Part Number
U105 LT1304CS8-5 06-6434
U106 LT1790BIS6-2.5 06-6691
U107 LMC7111BIM5X 06-6410
U108 LT1617ES5-1 06-6760
U109 SM5420-030-A-P-T 2311127
U110 PIC18LF2520-I/SO 06-6696
U111 INA126UA 06-6726
U112 MCP4822-E/SN 06-6722
U113 MCP9800AOT-M/OTG 06-6687
U114 MAX809JTRG 06-6423
U115 LMC7111BIM5X 06-6410
CR100 CMSH1-40M 07-6411
CR101-CR103 CMPD2005S 07-6468
CR104 MMBZ5270BL 07-6474
CR105 CMPD2005S 07-6468
CR106 CMPSH-3 TR 07-6489
CR107 CMPD3003S 07-6515
R100 100K, 250mW, 1% 12-7834
R101 365K, 250mW, 1% 12-7049
R102 61.9K, 250mW, 1% 12-7026
R103 1M, 250mW, 1% 12-7844
R104 22.1Ohm, 250mW, 1% 12-7055
R105 100K, 250mW, 1% 12-7834
R106 365K, 250mW, 1% 12-7049
R107 15K, 250mW, 1% 12-7998
R108 47.5K, 250mW, 1% 12-7872
R109 27K, 250mW, 1% 12-7243
R111 100K, 3266X1-104 09-6823
R112 154K, 250mW, 1% 12-7197
R113 221Ohm, 250mW, 1% 12-7017
R114 249K, 250mW, 1% 12-7862
R115 82.5K, 250mW, 1% 12-7849
R116 1.5M, 250mW, 1% 12-7987
R117 27K, 250mW, 1% 12-7243
R118 82.5K, 250mW, 1% 12-7849
R119 1M, 250mW, 1% 12-7844
R121 182K, 250mW, 1% 12-7860
R122 90.9K, 250mW, 1% 12-7224
R124 61.9K, 250mW, 1% 12-7026
R125 499K, 250mW, 1% 12-7037
Ludlum Measurements, Inc. Page 20 June 2018
MODEL 9-4 Technical Manual Section 8
CONNECTORS
SWITCHES
MISCELLANEOUS
R126 10M, 250mW, 1% 12-7996
R128 750K, 250mW, 1% 12-7882
R130 10M, 250mW, 1% 12-7996
R131 3.01M, 250mW, 1% 12-720
R134 100K, 250mW, 1% 12-7834
R135 221K, 250mW, 1% 12-7845
R136 10K, 250mW, 1% 12-7839
R137 1M, 250mW, 1% 12-7844
R138 1K, 250mW, 1% 12-7832
R139 1.96K, 250mW, 1% 12-7065
R140 1K, 250mW, 1% 12-7832
R141-R143 1M, 250mW, 1% 12-7844
R144 1K, 250mW, 1% 12-7832
R145 100Ohm, 250mW, 1% 12-7840
R146-R149 1M, 250mW, 1% 12-7844
R150 1K, 250mW, 1% 12-7832
R151 221K, 250mW, 1% 12-7845
R152, R153 1M, 250mW, 1% 12-7844
R154 100Ohm, 250mW, 1% 12-7840
R155 1M, 250mW, 1% 12-7844
R156 100Ohm, 250mW, 1% 12-7840
R157 1K, 250mW, 1% 12-7832
R158 47.5K, 250mW, 1% 12-7872
R159 100K, 3266X1-104 09-6823
R160 124K, 250mW, 1% 12-7032
R161 1MK, 250mW, 1% 12-7844
R162 10K, 250mW, 1% 12-7839
R163 301Ohm, 250mW, 1% 12-7863
P100 1-640456-0 MTA100×10 13-8066
P101 640456-3 MTA100×3 13-8081
P102 53014-0610MOLEX 13-8974
P103 640456-5 MTA100×5 13-8057
P104 640456-4 MTA100×4 13-8088
SW100 3S1-SP9-B8-M2QE 7464-186
SW101 D5G0206S-9802 08-6761
SW102 3S1-SP9-B8-M2QE 7464-186
SW103 A123S1CWCQ 08-6781
JP100 5-146280-3 13-8571
L100, L101 22uH 21-9808
Ludlum Measurements, Inc. Page 21 June 2018
MODEL 9-4 Technical Manual Section 8
Electrometer Board,
Drawing 293 × 670
CAPACITORS
INTEGRATED
CIRCUIT
DIODES
RESISTORS
RELAYS
CONNECTORS
BOARD Completely Assembled
Electrometer Board 5293-442
C1 2pF, 200V 04-5726
U1 IC-LMP7721MA 06-6728
CR1-CR2 CMPSH-3 07-6489
R1 1M, 1/4W, 1% 12-7844
R2 500G, 330mW, 20% 12-7248
R3 4.2G, 1W, 10% 12-8022
R6 27K, 1/4W, 1% 12-7243
R7 500G, 330mW, 20% 12-7248
R8 1M, 1/4W, 1% 12-7844
R9 27K, 1/4W, 1% 12-7243
RL1 Bobbin Assembly 4293-541
SPST-NC MDSR-7 Reed Assy. 7293-532
RL2 Bobbin Assembly 4293-538
SPDT MDRR-DT Reed Assy. 7293-543
P1 1-640456-0 MTA100×10 13-8066
P2 103186-1 13-847
Ludlum Measurements, Inc. Page 22 June 2018
MODEL 9-4 Technical Manual Section 9
Section
9
Drawings
MAIN BOARD SCHEMATIC, Drawing 293 × 711 (4 Sheets)
MAIN BOARD LAYOUT 293 × 712 (2 Sheets)
ELECTROMETER BOARD, Drawing 293 × 670
ELECTROMETER BOARD LAYOUT 293 × 672
Ludlum Measurements, Inc. Page 23 June 2018
Loading...