Ronan X90 User Manual

Instructions

and

Operating Manual

SERIES X90

POINT LEVEL MONITORS

POINT LEVEL MONITORS
SERIES X90

Instructions and Operating Manual

Customer’s Name ____________________

Customer’s P.O. No.
__________________

Ronan Job No. ______________________

TABLE OF CONTENTS

1.0

General Description .........................................................................................................

2.0

Specifications (Standard) .................................................................................................

3.0

Theory of Operation .........................................................................................................

4.0

Functional Options ...........................................................................................................

4.1

High-Limit Process Alarm ................................................................................................

4.2

Low-Limit Process Alarm .................................................................................................

4.3

Failure Alarm ...................................................................................................................

5.0

Time Delay Options .........................................................................................................

5.1

Relay Contacts ................................................................................................................

6.0

Circuit Description ...........................................................................................................

7.0

Installation and Electrical Connection—General ...............................................................

7.1

Remote Probe X90-1004 ..................................................................................................

7.2

Model X90GPE ................................................................................................................

7.3

Integral Model X90-1005 ..................................................................................................

8.0

Calibration Controls .........................................................................................................

9.0

Calibration—General .......................................................................................................

9.1

Calibration with Process Material .....................................................................................

9.2

Calibration without Process Material ................................................................................

9.3

Time Delay ......................................................................................................................

9.4

Response Time ...............................................................................................................

10.0

Troubleshooting ...............................................................................................................

11.0

Radiation Safety ..............................................................................................................

11.1

Field Intensity Calculation ................................................................................................

11.2

NRC Regulations .............................................................................................................

11.3

Periodic Leakage Test .....................................................................................................

11.4

Radiation Publications .....................................................................................................

11.5

Abandonment and Disposal .............................................................................................

11.6

Prohibition of Operation ...................................................................................................

11.7

Mounting and Start-up .....................................................................................................

11.8

Well Source Holders SA-4, SA-10, SA-15 ........................................................................

11.9

Standard Sources SA-1, SA-8 ..........................................................................................

11.10

Mandatory Reporting .......................................................................................................

12.0

Leak Test Procedures for Sealed Sources ........................................................................

12.1

Ronan Leak Testing Service ............................................................................................

12.2

Using the Leak Test Kit ....................................................................................................

13.0

Parts Lists

X90-1004 or X90-1004X Probe .........................................................................................

X90-301(V) ......................................................................................................................

X90-1005 .........................................................................................................................

14.0

Drawings and Schematics

Schematic—X90-1005 Point Level Monitor ......................................................................

Schematic—X90-301(V) Relay Circuit .............................................................................

Schematic—X90-301(V) Component Layout ....................................................................

Schematic—X90-1004 Driver Board ................................................................................

Outline Drawing—X90-1004 Component Layout Driver Board ..........................................

Outline Drawing—X90-SM/X90-301(V) Interconnect Wiring .............................................

Outline Drawing—X90 Remote G-M Tube Wiring .............................................................

Schematic—X90-301(V) Terminal Arrangement ..............................................................

Outline Drawing—X90 Explosion-Proof Housing ..............................................................

Outline Drawing—Single-Point Chassis Model X90GPE ...................................................

Outline Drawing—X90 Remote Tube Housing ..................................................................

Outline Drawing—Front and Rear Panels, X90 Gamma Switch ........................................

Outline Drawing—NEMA Type 4 Enclosure ......................................................................

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Warranty

workmanship under normal conditions of use and service, and will repair or replace any component
found to be defective, on its return, transportation charges prepaid, within one year of its original pur­chase. this warranty carries no liability, either expressed or implied, beyond our obligation to replace the
unit which carries the warranty.

Ronan warrants equipment of its own manufacture to be free from defects in material and

1.0 GENERAL DESCRIPTION

The Ronan Series X90 Point Level Monitor economically
and reliably solves many process problems in which
noise, temperature, abrasive or corrosive conditions
preclude the effective utilization of sonic, capacitative,
float or other techniques. This is a non-contact system.

Normally, a small Cesium-137 radioisotope source is
housed in a lead-filled shielding enclosure known as the
source holder. This holder is equipped with a shuttering
mechanism and the means for containing the radiation
and collimating or directing the radiated energy toward
the sensor, which is directly opposite the source along a
line or level to be measured. Radiation in all directions is
attenuated to a safe value by the lead shielding. The
source holder is mounted on or adjacent to the vessel
whose content it is desired to monitor.

When the source holder shutter is opened, radiant
energy is directed toward the sensor. In the absence of
the process, this sensor sees only a small amount of
radiation but, when the process is present, a large
percentage of this radiation is absorbed. This absorption
of radiation by the process causes a change in the
radiation at the sensor. When this occurs, a relay
contact signals that the level change has been observed.

The passage of radiant energy through the process
causes no contamination and cannot make the process
or container walls radioactive. These systems may be
used anywhere, including the food processing industries.

For most applications, all components of the system are
externally mounted. Therefore, installation is simple and
requires no major mechanical modification or down-time.

The standard Ronan Model X90-301(V) gamma switch
uses Cesium-137 as the source of gamma rays.
Cesium-137 is a 0.66 MEV gamma ray emitter with a
half-life of 30 years. The radioisotope material is sealed
in a double-welded, stainless steel capsule. The source
type and strength (activity) supplied depends on the
individual application, and is printed on the yellow and
magenta caution label affixed to the 3 source holder.
The standard source holder is lead-filled and equipped
with a two-position ON/OFF shutter mechanism. The

handle and shutter mechanism can, by means of a
combination padlock, be securely locked in the OFF

position during shipping, installation, storage or process­down intervals.

Well sources are supplied with actuator rods, which can
be used to extend the source into the vessel or retract
the source into the storage source holder.

CAUTION: Any malfunction of the source holder must
be immediately reported to Ronan Engineering for repair
or replacement of the source holder. Under no
circumstances may the source holder be taken apart.

Should it be necessary to ship the source holder back to
Ronan, contact Ronan Engineering for detailed shipping
instructions.

A Geiger-Mueller tube is used as the sensor for
detecting the gamma radiation. The G-M tube consists
of a gas-filled cylinder with a central anode. The anode
is connected via a high ohmic resistance to a dc voltage
of 500 V. Conduction occurs when the gamma radiation
ionizes the gas in the tube. Each ionizing event
produces a pulse, the rate of these pulses being
proportional to the field strength of the ionizing radiation,
i.e., incident field intensity. The output of the G-M tube
is processed by an electronic circuit in the X90-301(V)
module and the material level is indicated by either an
ALARM or NORMAL signal.

_____________________________________________

2.0 SPECIFICATIONS (STANDARD)

The X90 is a solid-state instrument available in two
designs. The Model X90 Detector with integral
electronics has a combined detector and switch
assembly located at the vessel. The Model X90-1004
Detector with remote electronics module may be field­located or remotely located in a control room

Detector: Integral: Geiger-Mueller tube Remote:
Geiger-Mueller tube

Radiation at Detector: Integral: 0.1 mR/hr min.
Remote: 0.1 mR/hr min.

Detector Housing: Integral: 4” Schedule 40 carbon
steel pipe (type 304 stainless steel also available);
mount to flat plate bracket Remote: Type 304 stainless
steel; explosion-proof housing; mount with conduit clamp

Housing Classifications:

Groups A, B, C, D; Class II, Division 1, Groups E, F, G
Remote: Class I, Division 1, Groups A, B, C, D; Class
II, Division 1, Groups E, F, G

Ambient Temperature Range:

(-40° to 85°C) Remote: -40° to 185°F (-40° to 85°C)

Overall Length: Integral: 20” (50.80 cm) Remote:
8” (20.32 cm)

Approximate Weight:

Remote: 4.4 lbs. (2 kg)

Power: Integral: 115/230 VAC ± 15%, 40/60 Hz
Remote: 115/230 VAC ± 15%, 50/60 Hz

Power Consumption: Integral: 7 watts per alarm
Remote: 7 watts per alarm point

Relay Output: Integral: DPDT 3 A at 30 VDC; 3 A at
120 VAC Remote: DPDT 3 A at 30 VDC; 3 A at 120
VAC

Analog Output: Remote: 0-1 V

Failure Alarm:

Integral: Included Remote: Included

Integral: Class I, Division 1,

Integral: -40° to 185°F

Integral: 37.4 lbs. (17 kg)

Time Delay Range:

20 seconds normal); jumper-selectable Remote: .05 to
20 seconds (10 or 20 seconds normal); jumper­selectable

Display: Integral: LED status indicator Remote: LED
status indicator

Accuracy: Integral ± 1/8” Remote: ± 1/8”

All equipment approved by CSA.

—————————————————————————

Integral: 0.5 to 20 seconds (10 or

3.0 THEORY OF OPERATION

The Ronan Series X90 gamma switches provide an
alarm signal whenever the radiation field intensity at the
detector (G-M tube) changes by more than its
predetermined value. The variation in the field intensity
may be due to either a change in the level (at the limit),
or a change in the density of the process material in the
radiation beam path. In a typical arrangement, the X90
detects the level of liquid in a vessel when it has
exceeded a predetermined limit. The level limit is
defined by an imaginary straight line drawn from the
source to the detector.

Figure 1: Source and Detector

When the feed valve is open, liquid is fed into the vessel
and the liquid level rises. The liquid level will rise until it
interrupts the gamma ray beam. There is then a change
in the field intensity at the detector due to absorption by
the process of some of the energy present in the beam,
and the instrument puts out an alarm signal in the form
of a relay contact changeover. This signal may be used
to close the feed valve and/or activate an annunciator.
As the liquid is used from the vessel, the level will fall,
thus again exposing the detector to the gamma radiation
and the feed valve will be opened when the contacts
revert to normal.

This is an example of a high limit switch, i.e., the process
level is not allowed to rise above a certain limit.

Conversely, the source and the detector may be lowered
to below the liquid level and the system functions as a
low limit switch, in which case the system will produce an
alarm when the liquid level falls below this low limit. The
liquid itself may be under pressure at high temperature
or even corrosive, but its characteristics will not affect
the switch, since the system components are outside of
the vessel.

A time delay based on the measurement controls the
interval between radiation level change and alarm. A
hysteresis band about the required level prevents
fluttering and spurious alarm situations.

3.1 Optional Gaging Configurations

3.1.1 Model X90-1004 Remote Probe: The Ronan

Model X90-1004 Remote Probe (located on vessel)
with the X90-301(V) switch electronics may be
located in a general purpose or Division II location.
This is the most widely used configuration. The
X90-1004X is a high-sensitivity tube, which may be
specified for very weak fields (0.1 mR/hr. or less).

3.1.2 Model X90-1005 Integral Switch: The
Ronan Model X90-1005 Integral Switch in a Model
X90-1001XP housing is usually specified when the
X90-301(V) switch electronics cannot be located in
a general purpose or Division II area. It may be
used when the vessel is easily accessible for
calibration and maintenance.

The Model X90-1005 contains the G-M tube sensor
and switch electronics on a single chassis and is
mounted on or just off the vessel wall.

—————————————————————————

4.0 FUNCTIONAL OPTIONS

4.1 High-Limit Process Alarm

The Process alarm relay will change over when the
level of process material rises above the set limit.

4.2 Low-Limit Process Alarm

The process alarm relay will change over when the
process level falls below the set limit.

4.3 Failure Alarm

In the case of the high-limit switch, under normal
conditions the G-M tube receives full radiation and
produces an output. This output will fall, producing
an alarm when either the radiation is interrupted by
the process level rising to above the set limit or the
G-M tube or its power supply fails. However, if the
tube or power supply fails, a failure alarm will be
actuated, indicating the problem is in the unit. If

the tube output does not indicate a minimum
background value (due to a malfunction in the G-M
tube or its power supply) the process (and failure, if
used) relay automatically changes over, indicating
an alarm condition.

The failure alarm will occur anytime the output from
the tube is zero.

—————————————————————————

5.0 TIME DELAY OPTIONS

The basic time constant is 0.5 seconds to 40 seconds,
depending upon the span setting. Additional time delays
available are 0.1, 5, 10 and 20 seconds.

For most applications, the 0.1 second jumper is used. If
false alarms occur, the time delay should be increased.
The delay is selected by a plug-in jumper located on the
electronics chassis printed circuit board.

5.1 Relay Contacts

Two Form-C (SPDT) contacts are provided.
Contact ratings are 3 A at 30 Ddc or 120 Vac
resistive. Other forms of contacts may be provided
on request.

If both sets of contacts are to be used for the
process alarm relay, jumper A10, B-11 and C-12
(located on the X90-301(V) printed circuit board or
X90-1005 printed circuit board for the integral
version.) For the integral Model X90-1005, 10A
contacts are provided as standard equipment.

If one set of contacts is to be used for a failure
alarm relay, D10, E-11 and F12 are jumpered.

—————————————————————————

6.0 CIRCUIT DESCRIPTION

The X90-301(V) and X90-1005 circuitry consists of a
stabilized ± 12 V and 500 V power supply, a voltage
integrator, comparator and logic alarms.

The output pulses from the G-M tube are fed through an
emitter follower to the input circuit. The pulses are + 12
V, 200 microseconds wide.

The G-M tube output is integrated and amplified by the
input circuit. The zero and span controls are used to
generate a 0 to 1 V output for low to high level
conditions.

This output is monitored using a simple VTOM across
the test points, AMP and TP GRN. A comparator circuit
will trip the relay circuitry at 0.9 V and reset at 0.2 V.
Jumpers on the circuit board are provided to make the
switch function as a high-level or low-level limit alarm.

Complete circuit schematics and wiring diagrams are
provided at the end of this manual.

7.0 INSTALLATION AND ELECTRICAL
CONNECTION—GENERAL

All equipment manufactured by Ronan Engineering is
carefully packaged and shipped to prevent shipping
damage. Any discrepancies between shipping contents
and invoice should be immediately reported to Ronan or
the Ronan representative.

All Series X90 system components (source holder,
integral switch and remote tube assembly) will tolerate
normal industrial vibration. However, in cases where
vibrators are attached directly to the vessel, the system
components must be mounted on adjacent building
framework or use special supports that provide a degree
of isolation.

When the axis of the G-M tube is placed parallel to the
surface of the process material and its side-facing
source, relay contact changeover will be obtained when
the set limit is exceeded by about one-half inch. When a
coarser level limit is appropriate, a broad band of about
five inches can be obtained by placing the detector axis
perpendicular to the surface of the process material. In
either case, an alarm is produced after the tube is
obscured from (or exposed to) the radiation from the
source.

Whenever possible, separate power sources should be
used for the X90 and the alarm circuit. With this
arrangement, the alarm will operate if the power to the
X90 is interrupted (provided, of course, the alarm circuit
has power available).

Local electrical codes must be followed for all wiring. All
conduit entrances should be sealed to prevent
condensed moisture or water from entering the
enclosures. The cable used to connect the remote G-M
tube should also be run through conduit. All explosion­proof housing covers must be replaced when the system
is in operation.

7.1 Remote Probe (X90-1004)

The G-M tube with X90-1004 driver board is placed
in an explosion-proof housing. This assembly is
mounted in position at the required level or point of
measurement and connected to the X90-301(V)
module by a four-conductor, shielded cable
supplied by Ronan Engineering.

Refer to drawing number C-1369-K for wiring of the
remote detector assembly and refer to drawing
number C-1359-K for designation of terminals on
the X90-301(V) module.

7.2 Model X90GPE

The X90-301(V) modules are plugged into X90GPE
surface-mount, single chassis enclosures. Access
to input/output and power connections are from the
front, beneath a convenient, snap-on cover.
Connections are located in a separate
compartment of the chassis and removal of the

module is not necessary in order to change wiring.
Grommeted holes are provided on the top and
bottom surfaces of the chassis for cable entry and
exit. Overall dimensions are 7.25” high X 4.5” wide
X 5.75” deep (18.42 cm X 11.43 cm X 14.6 cm).

Refer to drawing number C-1359-K for terminal
designations for power wiring and hook-up to the
remote probe driver board.

7.3 Integral Model X90-1005

Refer to drawing A-1697-K for rear-panel input
power wiring connections and relay contact wiring
connections.

—————————————————————————

8.0 CALIBRATION CONTROLS

The following front-panel controls are used in the set-up
procedure.

ZERO CONTROL is used to provide a zero voltage
signal at TP-AMP with the process level below the point
of measurement, under conditions of maximum radiation
at the G-M tube.

SPAN is used to provide a + 1.0 voltage signal at TP­AMP when the process level is above the point of
interest, under conditions of no radiation on the G-M
tube.

Three light-emitting diode (LED) DISPLAYS are
provided. These indicators will signal normal and level
alarm for process conditions and failure alarm.

The AMP TERMINAL is the output of the voltage
integrator. This output increases as the radiation on the
tube decreases and vice versa.

Calibration should be attempted only after all system
components have been securely mounted in position and
power and other connections made where required.
Check also that the correct jumpers have been installed
on the X90-301(V) or X90-1005 printed circuit board.

—————————————————————————

9.0 CALIBRATION—GENERAL

The output at the AMP terminal is a measure of level
present at the detector. This reading will be minimum or
near zero when the detector is fully irradiated (no
process) and the maximum or near 1.0 V when there is
process material between the source and the detector.

Therefore, for calibration any option, two voltage
readings are generated: 0.0 V with no process between
the source and the detector and + 1.0 V with process
between the source and the detector.

9.1 Calibration with Process Material

a) Switch on the power to the X90 and turn the
shutter handle on the source holder to the ON
position. Turn the SPAN control clockwise 20
turns; then 10 turns counterclockwise.

b) Lower the process level below the set limit and
adjust the ZERO control so that the AMP terminal
output is zero.

c) Raise the process level above the set limit and
again measure the voltage at the AMP terminal.

d) Adjust the SPAN control to obtain a reading of +

1.0 V at the AMP terminal.

After the switch has been calibrated using the
above method, the operation of the control relay,
NORMAL and ALARM indicators should be
checked by raising and lowering the process level
about the set limit. If all these operate as required,
the switch is considered calibrated.

9.2 Calibration without Process Material

a) Turn the source holder shutter to the ON
position.

b) Turn the SPAN control clockwise 20 turns; then
10 turns counterclockwise.

c) Take voltage reading at the AMP terminal.
Adjust the zero control to obtain an average 0.0 V
reading at the AMP terminal.

d) Turn the source OFF.

e) Adjust the SPAN control for an average + 1.0 V
reading.

f) Turn the source back ON for operation.

9.3 Time Delay

If false alarms occur, increase the time delay by
moving the delay jumpers on the printed circuit
board to a higher value.

9.4 Response Time

The response time of the amplifier is 0.5 to 40
seconds, depending on the SPAN setting.

Device

High limit switch

Low limit switch

Process alarm only

Process alarm and failure
alarm

Delays

High and G

Low and G

A-10, B-11, C-12

Failure relay and D-10, E-11,
F-12

Select one: 0.1 sec., 5 sec.,
10 sec., 20 sec.

Install

10.0 TROUBLESHOOTING

The X90 is constructed to require the minimum of
maintenance. Operated properly, it should not require
any maintenance for a considerable period of time.

Any necessary troubleshooting should start with the
power supplies. Ronan Engineering suggests that a
voltmeter with a resistance of at least 20 kohm/V be
used for measurement of voltages. Verify that the power
supplies are working before starting with the rest of the
circuitry. The operation of the main circuit may be
checked by adjusting the ZERO control to change the
amplifier voltage at the AMP terminal. Vary the voltage
and check the operation of the relay. Use the circuit
description and circuit schematic D-1357-K or D-1674-K
for reference.

If the relay circuit works properly using the ZERO control,
check the operation of the G-M tube with the source ON
and OFF to see if the tube responds.

For any major faults, we suggest the X90 be returned to
Ronan Engineering for service.

—————————————————————————

11.0 RADIATION SAFETY

The information in this section is intended for specific
licensees. The regulations and instructions pertain to
leak test and other procedures, which specific licensees
are authorized to perform. For general licensees this
section is included for information purposes only.

Most radioactive material used in gaging devices is
regulated by the United States Nuclear Regulatory
Commission (NRC). The NRC issues licenses to users
and manufacturers of gaging devices utilizing radioactive
materials and inspects sites where materials are used to
determine compliance with the terms of the license.

The NRC has issued rules on:

a) instructions to employees (10 CFR part 19);

b) the licensing of radioactive materials and devices (10
CFR part 30); and

c) radiation safety (10 CFR part 20).

During 1962, the NRC began entering into agreements
with individual states to transfer regulatory authority to
them. Known as “agreement states,” their regulations
closely parallel those of the NRC and are essentially
identical, except that the agreement states usually
regulate the use of all radiation-producing devices.

NOTE: Only those individuals specially licensed to
mount, repair, relocate and/or remove the part of the
gage containing the radioactive source may do so. Each
specific licensee should carefully read his particular
license to determine the exact conditions of his license.

Gamma-emitting radioactive material radiates
electromagnetic energy which is similar to light, except
that it readily penetrates opaque materials and is able to
pass through several inches of steel or other dense
material.

The ability to penetrate dense material can be used to
advantage in the measurement of process variables
such as density, level and thickness, where a change in
detected radiation indicates a change in process
variable.

Radiated energy is harmful to the human body when
absorbed at an excessive rate. For example, a glowing
incandescent lamp cannot be held in the hand without
causing severe discomfort or a painful burn. The hand
can be held close to the lamp for seconds, at a few
inches for hours or several feet away continuously. By
use of insulation surrounding the lamp or hand, the lamp
could be held indefinitely without discomfort or injury.

Radioactive energy and radiation is analogous to light
energy and radiation with the radioactive source taking
the place of the incandescent lamp. Permissible human
exposure to a radioactive source is dependent upon:

a) the number of millicuries of radioactive material in the
source (similar to the wattage rating of a lamp);

b) distance from the source;

c) amount of absorber between source and body;

d) amount of portion of the body receiving the radiation.

The term milliroentgen per hour (mR/hr) is a measure of
the radiation field intensity in air. W hen radiation is
absorbed by the body, the term rem or millirem (0.001
rem) is used. This distinction is necessary because not
all radiation affects the body in the same manner. For
gamma radiation, the millirem (mrem) is equal to the
milliroentgen.

The NRC limits the amount of radiation which a person
should receive to 1.25 rem per calendar quarter. This is
an average of about 100 mrem per week.

The 1.25 rem per calendar quarter limitation is a dose at
which there is no possibility of injury. However, since the
use of gamma radiation is relatively new, the history of
injury is not complete. Thus, it is wise to receive as little
radiation as possible. To guard against possible
overexposure and to maintain a record of personnel
routinely exposed to radiation, the NRC requires
monitoring of persons who are apt to receive more than
an average of 25 mrem per week or who are exposed to
a radiation field greater than 100 mr/hr. When personnel
monitoring is required, a record must be kept showing
the dose received. When records are kept, and if an
employee requests it, the employer must furnish a
written report of radiation exposure annually and on
termination of employment.

In the majority of Ronan installations, the source is
contained in a lead-filled source holder with an ON/OFF
mechanism. The holder is designed so that the radiation
field is 5 mR/hr or less at a distance of 12 inches from
the surface of the holder when is is in the OFF position.
When the source holder is mounted on the pipe or
vessel and turned to the ON position, the pipe walls,
process material and mounting bracket absorb most of
the radiation. Again, the field intensity is about 5 Mr./hr
at a distance of 12 inches from the surface of the gage.
Thus, a person would have to be within 12 inches of the
gage for 20 hours per week to receive 100 mrem. A
person would have to be within 12 inches of the gage for
five hours per week before he would be required to have
a personnel monitoring device, such as a film badge or a
dosimeter.

Long experience in the nuclear gaging industry with
hundreds of gages, where the source is contained in a
source holder, indicates that the dose received by
operators, maintenance personnel and supervisors
averages less than 25 mrem per week. Thus, for gages
where the source is contained in a source holder, it is
usually not necessary to provide any personnel with
monitors.

Whether or not monitoring devices are needed should be
determined at the gage site at the time of installation in
the form of an occupancy evaluation. Only those
persons specially licensed by the NRC or an agreement
state to install a radioactive device are qualified to make
an occupancy evaluation.

In some installations, it is impossible to mount the source
in a source holder. In these cases the source is usually
mounted in a source well. Installation of the source in
the well should be done as rapidly as possible. All
necessary equipment should be assembled prior to
opening the shipping box containing the source.

A trial installation using a dummy source is
recommended. A dummy source can easily be
fabricated from steel or brass using the outline drawing
of the source supplied by Ronan Engineering. When an
unshielded source is installed in a vessel or when it is
wipe tested, the radiation field is usually greater than 100
mR/hr. Thus, personnel monitoring in the form of film
badges or dosimeters is required. A record of the the
film badge or dosimeter reading must be kept on Form
NRC-5. Since records must be kept, the employer must
furnish to the employee, if requested, a record of the
employee’s radiation exposure annually and on
termination of employment.

Additional precautions are required when a gage is used
on a vessel large enough to permit entry of personnel.
With the source holder in the open position or when the
source is not removed from the source well, the radiation
field intensity inside the vessel can be high. A procedure
must be established so that personnel cannot enter the
vessel until the source holder is in the closed position or
the source is removed from the source well. The use of

padlocks on all man-way and access port covers is
acceptable. The key or combination for the locks should
be kept by the person responsible for radiation safety.

In some cases, when the vessel or pipe is empty, the
radiation field intensity of the outside of the pipe or
vessel will be such that personnel monitoring is required.
For installations using source holders, this problem can
easily be solved by turning the source holder to the OFF
position. For installations using sources in source wells,
where the radiation cannot be turned off, it may be
desirable to remove the source temporarily and return it
to its lead shielded shipping and storage container.

11.1 Field Intensity Calculation

The best method for determining the radiation field
intensity is by measurement with a survey meter.
However, the field intensity can be calculated fairly
accurately without a survey meter.

mCi k

D =

(d)

D = dose rate, mR/hr

mCi = millicurie value of source

d = distance to source in inches

k = constant 0.023 for AM-241

0.5 for CS-137

2.0 for CO-60

Suppose that for a certain installation the estimated
exposure time to the unshielded source is 10

minutes at an average body-to-source distance of
20 inches. The source is 10 millicuries of CS-137.

The dose rate would be:

And the dosage received would be:

2

rate Dose

(20)

dose Total ===

1000 X

10 X 0.5

2

min 10

min/hr 60

The radiation field intensity
can be calculated from:

1000 X

400

5

mr/hr 12.5 1000 X

===

mrem 2.08 mR/hr 12.5

Figure 2:

Radiation Transmission CS-137 for Various Materials

9

Calculate the radiation field intensity at 12 inches
from the surface of the vessel shown in Figure 3.
Total distance = 12 + 2 + 10 = 24 inches

Dose rate for unshielded source:

10 X 0.5

rate Dose ===

2

(24)

1000 X

476

5

Percent transmission of gamma radiation through
two-inch steel (vessel wall), 0.25-inch source well
wall = .18 X .83 = 0.517. Resultant field intensity =

8.6 X 0.517 = 4.45 mr/hr.

To estimate the dosage received by personnel
working in the vicinity of the source, the occupancy
must be known. Suppose that a man worked 24
hours per week within 12 inches of the vessel. He
would receive a dose in excess of 100 mr. He
would then require a monitoring device.

11.2 NRC Regulations

A current copy of the Title 10 Code of Federal
Regulations, Parts 19, 20 and 30 should be
obtained. These should be read thoroughly to
become familiar with the laws governing the use of
radioactive materials.

a) The “Individual User” listed on the “Application
for By-product Material License” (Form NRC-313) is
responsible for the source. If this person is
transferred or is changed to a position where he is
no longer responsible for the source, the license
must be amended prior to the assignment of the

mr/hr 8.6 1000 X

new user. [30.32, 30.33, 30.34, 30.38]

b) Use of the source is usually licensed for a
particular plant site. If the source is transferred to a
different plant site the license must be amended
prior to the transfer. [30.34 and 30.38]

c) A record of the initial radiation survey must be
kept for reference. [20.40 1 b]

d) Records of the periodic leakage test must be
maintained.

e) A label must be attached to the source holder,
or source well, stating the type and quantity of
radioactive material and the date of manufacture.
The label must bear the conventional radiation
symbol. An NRC-approved label is attached to the
source holder by Ronan Engineering prior to
shipment. For sources in source wells, and NRC­approved tag is placed on the source shipping and
storage contained. [20.203]

SOURCE HOLDER

SOURCE WELL
1/4” WALL
THICKNESS

SOURCE ROD

DETECTOR

SOURCE CS-137
10 MILLICURIE

10.00” 12.00”

304 SS
2” WALL
THICKNESS

Figure 3:

Dosage

f) The area in the vicinity of the source must be
posted with a radiation warning sign, if the radiation
field is greater than 5 mr/hr at a distance of 12
inches from the surface of the gage. [20.204a and

20.203]

g) Personnel monitoring is required when personnel
are apt to receive a dose in excess of 23 mrem/wk
or when they enter a radiation field greater than
100 mr/hr. [20.202a]

h) Whenever the source is to be discarded, it must
be returned to Ronan Engineering for proper
disposal. Ronan Engineering must be contacted
for detailed shipping instructions. [20.301a]

i) The regional operations office of the NRC must
be notified of any incident, such as a fire or
explosion, which involves the radioactive material
used in the gage. [20.403] (Ronan Engineering
should also be notified.)

j) If personnel monitoring is required [20.202a], a
record of the radiation exposure must be kept on
Form NRC-5 [20.401a and 20.401c] and, if the
employee requests it, written notification must be
given annually or on termination of employment.
[19.13]

k) If a person receives more than 1.25 rem per
calendar quarter, he must be notified in writing of
the exposure and the NRC must be notified.
[20.405]

l) A restricted area is defined in 10 CRF 20.3A(14)
and the permissible exposure to individuals in a
restricted area is given in 10 CFR 20.101. An
unrestricted area is defined in 10 CFR 20.3A (17)
and the permissible level of radiation in an
unrestricted area is given in 10 CFR 20.105(b).
Any area where an individual, if continuously
present, can receive a dose in excess of 2 mrem in
any one hour or where he can receive more than
100 mrem in any seven consecutive days must be
treated as a restricted area and access thereto be
under the control of the licensee.

m) Employees working in, or frequenting, a
restricted area must be advised of the restricted
area by posting a Form NRC-3 19.11(c). The NRC
regulations state that this form must be posted so
than employees can “observe a copy on the way to
or from their place of employment” in the restricted
area. Thus, Form NRC-3 could be posted at or
near the entry into the restricted area. If personnel
do not work in, or frequent, a restricted area, Form
NRC-3 need not be posted.

11.3 Periodic Leakage Test

Information about the periodic leakage test is
covered in Section 12.

11.4 Radiation Publications

For those who desire further information on
radiation safety and the handling of radioactive
material, the following publications are
recommended:

Radiation Dosimetery, Hine and Brownell
(Academic Press, Inc., 111 Fifth Avenue, New
York, NY 10003)

The following publications and National Bureau of
Standards handbooks are available from the
Superintendent of Documents, Washington, DC
98025:

Number Title
92 Safe Handling of Radioactive Materials

73 Protection Against Radiation from
Sealed Gamma Sources

11.5 Abandonment and Disposal

Abandonment or disposal is prohibited unless
transferred to persons specifically licensed by the
NRC or an agreement state. This means that the
gage cannot be abandoned, sold for scrap, or
placed in the trash bin. If the gage is no longer
needed, it must be shipped to a person or company
specifically licensed by the NRC or an agreement
state to receive the gage for disposal.

11.6 Prohibition of Operation

Operation is prohibited if there is indication of
failure of or damage to shielding or source
containment. If there is any damage to the gage,
or failure of the source rod mechanism, place the
source rod in the OFF position (if possible) and
telephone the field service manager at Ronan
Engineering [phone].

Care must be exercised when uncrating the gage.
If the crate is damaged in such a manner that the
gage might be damaged, Ronan Engineering
should be contacted for advice. If the lock is
missing, broken, or not locked, do not uncrate or
mount the gage in position. Call Ronan
Engineering for advice.

11.7 Mounting and Start-up

Anyone may mount the gages in position on the
vessel or pipes, do the electrical wiring, and turn
the electrical power switch ON, if the source holder
is locked in the OFF position.

When mounting the source holder in position, take
the necessary precautions to assure that it is not
dropped or damaged. Refer to the outline drawing
of the source holder in the back of this manual
before mounting it in position.

Only a person specifically licensed by the NRC or
an agreement state is allowed to remove the
source holder from its mounting or to dismantle it.

After these preliminary services are performed, a
person specifically licensed by the NRC or an
agreement state must do the start-up of the gage.
This involves unlocking the source holder and
turning it ON; testing for proper operation of the
source holder and position indicator; making the
initial radiation field intensity survey; and initial
testing for leakage of radioactive material. This
specifically licensed person must determine that
the gage is installed in such a manner that
personnel working in the vicinity of the gage will not
receive a radiation dose greater than 0.5 rem/yr.

The gage is shipped from the Ronan factory with
the source holder locked OFF. The combination ill
be given only to the specifically licensed person
performing the start-up and placing the gage in
service.

a copy of the tag attached to the lock follows:

Figure 4: Warning Tag

Device shall be tested for radioactive leakage and
proper functioning of source actuator rod at
installation, at source replacement and thereafter at
no longer than three-year intervals.

11.8 Well Source Holders SA-4, SA-10, SA-15

11.8.1 Source actuator: The actuator should

always move freely. There will be some slight
resistance to movement due to bearing friction of
the gasketed filling, which keeps out moisture and
dirt.

Do not force the source rod actuator.

If a portable radiation survey meter is available, the
radiation field intensity can be measured at the
back of the detector housing. With the source rod
in the STORE position, the field intensity should be
measurable. When the source is placed in the
well, the field intensity should decrease.

11.8.2 Source insertion procedure:

a) Open shutter and pin open with lock pin.
b) Loosen CGB fitting at source rod.
c) Remove handle and attach source extender rod.

e) Push source rod until source bottoms out in
well.
f) Tighten CGB fitting over source extender rod.

11.8.3 Source retraction procedure

a) Loosen CGB filling.
b) Pull source handle back until source rod locates
inside source tube. Source will hit positive stop
inside holder.
c) Push shutter to OFF. Lock with lock pin or
padlock.
d) Remove extender rod.
e) Remove handle from extender rod and attach to
source rod.

11.8.4 Wiping the test points: A wipe test and
radiation survey must be made before the source is
installed onto the vessel wall and before the source
is inserted into the well. The radiation protection
officer (RPO) or licensed personnel must supervise
the installation, source insertion and retraction.
The RPO must also classify the area based on the
radiation survey and personnel occupancy in the
vicinity of the gage.

The RPO must write control procedures for
personnel not to work or occupy the area around
the gage when the process is down, maintenance
on the vessel is performed, or when the vessel is
empty.

Anyone following the instructions of a leak test kit
may perform the wiping procedure, but only a
person or company specifically licensed by the
NRC or an agreement state may do the analysis for
radioactive material.

Using a cotton swab, wipe around the source rod
extending out the top of the source holder and at all
seams as shown in Figure 5. These areas are
most likely to be contaminated if the source leaks.
Do not touch the cotton-tipped end or allow it to
touch other objects, as this would spread
contamination if a leak is present.

After making the wipe test, replace the cotton swab
in the vial with the cotton-tipped end at the bottom.
Replace the cap on the vial, place the vial in the
shipping tube and replace the top on the shipping
tube. Send to: Ronan Engineering Company,
8050 Production Drive, Florence, KY 41042.

11.9 Standard Sources SA-1, SA-8

11.9.1 ON/OFF mechanism: To test the ON/OFF

mechanism, move the handle back and forth
several times between the ON and a OFF
positions. The handle should always move freely.
There may be some slight resistance to movement
due to bearing friction.

Do not force the handle.

If a portable radiation survey meter is available, the
radiation field intensity can be measured at points
around the detector housing.

11.9.2 Wiping the test point: Anyone following
the instructions of a leak test kit may perform the
wiping procedure, but only a person or company
specifically licensed by the NRC or an agreement
state may do the analysis for radioactive material.

Using a cotton swab, wipe around the rotor shaft on
the top of the source holder and at all seams, as
shown in Figure 6. These areas are most likely to
be contaminated if the source leaks. Do not touch
the cotton-tipped end or allow it to touch other
objects, as this would spread contamination if a
leak is present.

After making the wipe test, replace the cotton swab
in the vial with the cotton-tipped end at the bottom.
Replace the cap on the vial, place the vial in the
shipping tube and replace the top on the shipping
tube. Send to: Ronan Engineering Company,
8050 Production Drive, Florence, KY 41042.

Figure 5:

Wiping the Test Points (Well Sources)

11.10 Mandatory Reporting

Loss, theft or transfer of this device and failure of or
damage to the shielding or the source containment,
must be reported to the NRC or an agreement
state.

In addition to notifying the NRC or the agreement
state agency, Ronan Engineering should also be
notified, so that proper help can be provided.

If the gage is involved in a fire or explosion, the
area around the gage should be barricaded or
roped-off until the situation can be evaluated by a
specifically licensed person. Telephone Ronan
Engineering at [phone].

Figure 6: Wiping the Test Points (Standard

12.0 LEAK TEST PROCEDURES FOR
SEALED SOURCES

12.1 Ronan Leak Testing Service

The NRC requires that all sealed sources be tested
for leakage at specified intervals. Only Kr-85,
tritium and certain sources of very small activity (10
CFR 30.18a) are exempted from leak testing.

Ronan Engineering provides for users’ convenience
and safety the “Leak Testing Service.” The leak
testing procedure detailed in these instructions
applies only to the Ronan Model WK Leak Testing
Kit supplied with the Ronan Leak Testing Service.
The Ronan Model WK Leak Testing Kit is intended
for use on all sealed sources that are not exempt
from testing.

This service may be purchased from Ronan on a
contract basis for five years when wipe testing at
six-month intervals is required or on a one-time
basis in the case of three-year wipe test intervals.
The service must be purchased for each individual
source. If the service is retained, Ronan will send
the required number of leak test kits, consisting of:

a) A cotton swab (“Q-tip”) saturated in radiac
wash, contained in a small plastic tube.

b) Special instructions on its use.

c) Leak test forms.

After the sealed sources have been wiped by the

materials, issue a report based on the results and
forward a copy of the results to the customer
immediately.

12.2 Using the Leak Test Kit:

For instructions on using the Leak Test Kit see
section 11.8.4 for well sources or section 11.9.2 for
standard sources.

Return the shipping tube, prepaid, via United
Parcel Services (UPS). Do not send the shipping
tube via conventional mail, as postal regulations
prohibit mailing of radioactive material in this form.

Upon receipt of the wipe, Ronan will perform a
sensitive analysis to determine the presence of
radioactive material. If the wipe is contamination­free, a notice will be sent via mail that the source is
leak-free. If radioactive material exceeding .005
microcuries is detected on the wipe, an emergency
notification will be sent via telegram or telephone,
advising that the source holder must be taken out
of service and sent back for repair. The emergency
notification will contain detailed instructions for
removal and shipment of source holder.

Ronan will maintain records of each leak test
analysis performed. The records will include the
name and address of the customer; the date the
sample was collected; the individual collecting the
sample; the person performing the analysis; the
date the analysis was performed; the unique
identification of the source being tested; the
radioactive material and mass number contained in
the source; and the results of the test expressed in

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-1004 or X90-1004X Probe

Item

1 1 R1 RC20GF105J Resistor, Carbon, ½ W, 5%, 1.0 Meg Allen-Bradley

2

3

4 1 R4 RC20GF203J Resistor, Carbon, ¼ W, 5%, 20 k Allen-Bradley

5

6 1 R6 RC07GF104J Resistor, Carbon, ½ W, 5%, 100 k Allen-Bradley

7

8

9 1 Q2 2N6725 Transistor, NPN Darlington National

10

11 2

Qty.

1

1

1

1

1

1

ID

R2

R3

R5

C1

Q1

Part No.

RC20GF335J

RC20GF225J

RC20GF183J

DPMS-6D5

2N4392

350-1300-11-07- Terminal Cambion

Description

Resistor, Carbon, ½ W, 5%, 3.3 Meg

Resistor, Carbon, ¼ W, 5%, 2.2 Meg

Resistor, Carbon, ¼ W, 5%, 18 k

Capacitor, 5000 pFd, 600 Vdc

Transistor, N-CH JFET

Circuit Board

Vendor

Allen-Bradley

Allen-Bradley

Allen-Bradley

CDE

National

CCI

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-1004 or X90-1004X Probe (continued)

Item

12

Qty.

4

ID

Part No.

350-1246-11-07- Terminal

Description

Vendor

Cambion

13 2

14

15

16
17 1
18 1

19

20
21 1

1

1

1

1

1

A-1106-K Bushing, Mounting Ronan
A-1107-K Bushing, Support Ronan

8404
GM-R-1 or Geiger-Mueller Tube Ronan

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-301(V)

Item

1
2 2 R2,3 RN60C1004 Resistor, Carbon, ½ W, 1%, 1 Meg Allen-Bradley
3 2 R4,5 RN55C2492 Resistor, M.F., ¼ W, 1%, 24.9 k Mepco

4
5 1 R7 RC07GF332J Resistor, Carbon, ¼ W, 5%, 3.3 k Allen-Bradley
6 1 R8 RC07GF562J Resistor, Carbon, ¼ W, 5%, 5.6 k Allen-Bradley

7
8 1 R10 RC07GF101J Resistor, Carbon, ¼ W, 5%, 100 ohms Allen-Bradley
9 1 R11 RN55C3012 Resistor, M.F., ¼ W, 1%, 30.1 k Mepco

10
11
12 2 R13,15 RN55C4993 Resistor, M.F., ¼ W, 1%, 499 k Mepco

13
14 1 R17 RN55C1210 Resistor, M.F., ¼ W, 1%, 121 ohms Mepco
15 2 R18,28 RC07GF472J Resistor, Carbon, ¼ W, 5%, 4.7 k Allen-Bradley

16
17 2 R20,24 RN55C1003 Resistor, M.F., ¼ W, 1%, 100 k Mepco
18 1 R21 RN55C2490 Resistor, M.F., ¼ W, 1%, 249 ohms Mepco

19
20 1 R23 RN55C1001 Resistor, M.F., ¼ W, 1%, 1 k Mepco
21 1 R25 RN55C7502 Resistor, M.F., ¼ W, 1%, 75 k Mepco

22

Qty.

1

1

1

2

ID

R1

R6

R9

R12,16

Part No.

RC32GF913J

RC07GF202J

RN55C8250

89PR10K

1

2

1

1

R14

R19

R22

R26

RN55C3743

RC07GF105J

RN55C4990

68WR10K

Spacer, ¼”, ¾L, 6-32 Thread

Weather-proof box

SST 1” or ¾” Pipe

SST 1” or ¾” Pipe

Aluminum Label

Interconnect Cable, 4 COND/SH

Description

Resistor, Carbon, 1 W, 5%, 91 k

Resistor, Carbon, ¼ W, 5%, 2 k

Resistor, M.F., ¼ W, 1%, 862 ohms

Trim Potentiometer, Cermet, 10 k

Resistor, M.F., ¼ W, 1%, 374 k

Resistor, Carbon, ¼ W, 5%, 10 M

Resistor, M.F., ¼ W, 1%, 499 ohms

Trim Potentiometer, Cermet 10 k

Ronan

Ronan

Ronan

Ronan

Belden

Vendor

Allen-Bradley

Allen-Bradley

Mepco

Beckman

Mepco

Allen-Bradley

Mepco

Beckman

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-301(V) (continued)

Item

23
24
25
26 3 R31,32,35 RC07GF680J Resistor, Carbon, ¼ W, 5%, 680 Allen-Bradley
27
28
29 5 C4,7,8,9,10 280AE/A100K Capacitor, Met. Polyester, .1 mfd Phillips
30
31
32 2 C12,13 437ET/G220 Capacitor, Electrolytic, 220 mfd/40 V Phillips
33

34

35 1 C17 344CH/680K Capacitor, Meg. Polycarb., .68 mfd Phillips
36
37 1 C19 199D156X

38
39 2 D1,2 MR250 Diode, Rectifier, HV Motorola
40 2 D10,11 1M200ZS10 Diode, Zener Motorola
41
42 4 D7,8,9,18 1N827A Diode, Reference Zener, 6.2 V Motorola
43 3 D12,13,16 1N457A Diode, General Purpose Fairchild
44
45 1 D15 5082-4650 Light Emitting Diode, Red H.P.
46 1 D17 5082-4550 Light Emitting Diode, Yellow H.P.
47
48 1 Q1 MJE-340 Transistor, NPN Motorola
49 1 Q2 2N3638 Transistor, PNP National
50
51 1 A2 LM307N Operating Amplifier National
52 1 A3 LF355N Operating Amplifier National
53
54
55 1 IC1 7806C Voltage Regulator, 6 V Motorola
56
57 1 IC3 MC14001B Quad 2” NOR Gate Motorola
58 1 IC4 NE555N 555 Timer Signetics
59
60 1 IC6 DS3633N Driver National
61 2 RY1,2 X23DC-24GP Relay, 4 PDT, 24 Vdc Potter &

62

Qty.

3
2

2
2

1
1

2

1

1

4

1

1

1

1

1

2

ID

R27,33,34
R29,30

C1,2
C3,4

C6
C11

C14,15

C16

C18

D3,4,5,6

D14

A1

A4

IC2

IC5

Part No.

RC07GF104J
RC07GF155J

65-DD30-102
280CF/A470K

22263003221
334CH/470K

198D685X
9035K1
719A1GG105K
101SB

UK16-103

0025-DB1

1N4005

5082-4950

LM201AH

LM1458N

7906C

DS3634N

Description

Resistor, Carbon, ¼ W, 5%, 100 k
Resistor, Carbon, ¼ W, 5%, 150 k

Capacitor, .001 mfd/1 kV
Capacitor, Met. Polycarb., .47 mfd/630 V Phillips

Capacitor, 220 pFd
Capacitor, Met. Polycarb., .47 mfd

Capacitor, Tantalum, 6.8 mfd/35 V

Capacitor, Meg. Polyester, 1 mfd/100 V

Capacitor, Ceramic, .01 mfd/16 V
Capacitor, Tantalum, 15 mfd/20 V Sprague

Diode, Rectifier

Light Emitting Diode, Green

Operating Amplifier

Dual Operating Amplifier

Voltage Regulator, 6 V

Driver

Relay Socket

Vendor

Allen-Bradley
Allen-Bradley

Centralab

Phillips
Phillips

Sprague

Mepco

Centralab

Fairchild

H.P.

National

National

Motorola

National

Brumfield
Potter &
Brumfield

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-301(V) (continued)

Item

63

64
65

66

67
68 3

69

70
71 1

72

73
74 1

75

76
77 1

78

Qty.

2

1

2

1

1

1

2

1

6

ID

T1

Part No.

1598-102 Test Jack, Red H.H. Smith

1598-103

HLMP-0103 Mounting Clip and Ring, LED H.P.

X90-301

X81-B35

X90-C1348K

461-2871-01-03­12
450-3704-01-03­00

Description

Relay Holdown

Test Jack, Black

Nuts for Test Jacks

Transformer

Front Panel Ronan

Panel Fastener

Extruded Handle
Engraved Label Ronan

Brackets

Circuit Board
Shorting Plug Cambion

Connector Jack

Vendor

Potter &
Brumfield

H.H. Smith

Tinnerman

MCI Ltd.

Southco

Ronan

Ronan

CCI

Cambion

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-1005

Item

1
2 2 R2,3 RN60C1004 Resistor, Carbon, ½ W, 1%, 1 Meg A.B.

3

4
5 1 R7 RC07GF332J Resistor, Carbon, ¼ W, 5%, 3.3 k A.B.

6

7
8 1 R10 RC07GF101J Resistor, Carbon, ¼ W, 5%, 100 ohms A.B.

9

10
11

12
13 1 R14 RN55C3743 Resistor, M.F., ¼ W, 1%, 374 k Mepco

14

15
16 2 R19 RC07Gf105J Resistor, Carbon, ¼ W, 5%, 10 M A.B.

17

18
19 1 R22 RN55C4990 Resistor, M.F., ¼ W, 1%, 499 ohms Mepco

Qty.

1

2

1

1

1

1

2

ID

R1

R4,5

R6

R8

R9

R11

R12,16

Part No.

RC32GF913J

RN55C2492

RC07GF202J

RC07GF562J

RN55C8250

RN55C3012

89PR10K

Description

Resistor, Carbon, 1 W, 5%, 91 k

Resistor, M.F., ¼ W, 1%, 24.9 k

Resistor, Carbon, ¼ W, 5%, 2 k

Resistor, Carbon, ¼ W, 5%, 5.6 k

Resistor, M.F., ¼ W, 1%, 862 ohms

Resistor, M.F., ¼ W, 1%, 30.1 k

Trim Potentiometer, Cermet, 10 k

Vendor

A.B.

Mepco

A.B.

A.B.

Mepco

Mepco

Beckman

2

1

2

2

1

R13,15

R17

R18,28

R20,24

R21

RN55C4993

RN55C1210

RC07GF472J

RN55C1003

RN55C2490

Resistor, M.F., ¼ W, 1%, 499 k

Resistor, M.F., ¼ W, 1%, 121 ohms

Resistor, Carbon, ¼ W, 5%, 4.7 k

Resistor, M.F., ¼ W, 1%, 100 k

Resistor, M.F., ¼ W, 1%, 249 ohms

Mepco

Mepco

A.B.

Mepco

Mepco

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-1005 (continued)

Item

20 1 R23 RN55C1001 Resistor, M.F., ¼ W, 1%, 1 k Mepco

21

22
23

24

25
26 3 R31,32,35 RC07GF680J Resistor, Carbon, ¼ W, 5%, 680 A.B.

27

28
29 1 R39 RC20GF225J Resistor, ¼ W, 5%, 2.2 Meg A.B.

30

31
32 1 R42 RC07GF104J Resistor, ½ W, 5%, 100 k A.B.

33

34
35 5 C5,7,8,9,10 280AE/A100K Capacitor, Met. Polyester, .1 mfd Phillips

36

37
38 2 C12,13 437ET/G220 Capacitor, Electrolytic, 220 mfd/40 V Phillips

39

40 1 C16 719A1GG105K

41

42
43 1 C19 199D156X

44
45 1 C20 453P223-

46
47 2 D10,11 1M200ZS10 Diode, Zener Motorola
48 4 D3,4,5,6 1N4005 Diode, Rectifier Fairchild

49
50 3 D12,13,16 1N457A Diode, General Purpose Fairchild
51 1 D14 5082-4950 Light Emitting Diode, Green H.P.

52
53 1 D17 5082-4550 Light Emitting Diode, Yellow H.P.
54 1 Q3 2N4392 Transistor, N-CH JFET National

55
56 1 Q1 MJE-340 Transistor, NPN Motorola
57 1 Q2 2N3638 Transistor, PNP National

58
59 1 A2 LM307N Operating Amplifier National
60 1 A3 LF355N Operating Amplifier National

61
62
63 1 IC1 7806C Voltage Regulator, 6 V Motorola

Qty.

1

1

3

2

1

1

1

1

1

2

1

1

2

1

1

1

2

4

1

1

1

1

ID

R25

R26

R27,33,34

R29,30

R37

R38

R4

R41

R36

C3,4

C6

C11

C14,15

C17

C18

C21

D1,2

D7,8,9,18

D15

Q4

A1

A4

Part No.

RN55C7502

68WR10K

RC07GF104J

RC07GF155J

RC20GF105J

RC20GF335J

RC20GF203J

RC20GF183J

RC07GF223J

280CG/A470K

22263003221

344CH/470K

198D685X
9035K1

101SB
344CH/680K

UK16-103

0025-DB1
DPMS-6D5

X9400JA3
MR250

1N827A

5082-4650

2N6725

LM201AH

LM1458N

Description

Resistor, M.F., ¼ W, 1%, 75 k

Trim Potentiometer, Cermet 10 k

Resistor, Carbon, ¼ W, 5%, 100 k

Resistor, Carbon, ¼ W, 5%, 150 k

Resistor, ½ W, 5%, 1.0 Meg

Resistor, ½ W, 5%, 3.3 Meg

Resistor, ¼ W, 5%, 20 k

Resistor, ¼ W, 5%, 18 k

Resistor, ½ W, 5%, 22 k

Capacitor, Met. Polycarb., .47 mfd/630 V Phillips

Capacitor, 220 pFd

Capacitor, Met. Polycarb., .47 mfd

Capacitor, Tantalum, 6.8 mfd/35 V

Capacitor, Met. Polyester, 1 mfd/100 V Mepco

Capacitor, Met. Polycarb., .68 mfd

Capacitor, Ceramic, .01 mfd/16 V
Capacitor, Tantalum, 15 mfd/20 V Sprague

Capacitor, 5,000 pFd/600 Vdc
Capacitor, .022 mfd/400 Vdc Sprague

Diode, Rectifier, HV

Diode, Reference Zener, 6.2 V

Light Emitting Diode, Red

Transistor, NPN Darlington

Operating Amplifier

Dual Operating Amplifier

Vendor

Mepco

Beckman

A.B.

A.B.

A.B.

A.B.

A.B.

A.B.

A.B.

Phillips

Phillips

Sprague

Phillips

Centralab

CDE

Motorola

Motorola

H.P.

National

National

National

PARTS LIST—SERIES X90 POINT LEVEL MONITOR

X90-1005 (continued)

Item

64 1 IC2 7906C Voltage Regulator, 6 V Motorola

65
66 1 IC4 NE555N 555 Timer Signetics
67 1 IC5 DS3634N Driver National

68
69 2 RY1,2 K10P11D15 Relay, 4 PDT, 24 Vdc Potter &

70

71 2

72

73
74 2

75

76
77 1

78

79
80 2

81

82
83 1

84

85 6

86

87 1
88 1

89
90 1
91 1 F1 MDS-¼ Fuse, ¼ A, Slo-Blo Littlefuse

92

Qty.

1

1

2

1

3

1

1

1

1

2

1

1

1

ID

IC3

IC6

T1

Part No.

MC14001B

DS3633N

1598-102

1598-103

HLMP-0103

X90-301
X90D5 Chassis Ronan

B1615K

X90-B3
10016-B-0256 Handle Amatom

X90-C10

X91-A11
X90-D1316K Circuit Board CCI

461-2871-01-03­12
450-3704-01-03­00
GM-R-1 or
GM-R-1X
GFT-3 Terminal Strip Curtis

GFT-6 Terminal Strip Curtis

SCU-15D1/4
3420226 Fuse Holder Littlefuse

Description

Quad 2” NOR Gate

Driver

Relay Socket

Relay Holdown Potter &

Test Jack, Red

Test Jack, Black
Nuts for Test Jacks Tinnerman

Mounting Clip and Ring, LED

Transformer

Front Panel

Rear Panel

Bracket

Brackets

Shorting Plug

Connector Jack Cambion

Geiger-Mueller Tube

Connector

Vendor

Motorola

National

Brumfield
Potter &
Brumfield

Brumfield
H.H. Smith

H.H. Smith

H.P.

MCI Ltd.

Ronan

Ronan

Ronan

Ronan

Cambion

Ronan

EDAC