BERTHOLD TECHNOLOGIES LB4710-050, LB4710-060, LB4710-160, LB4710-080, LB4710-090 User Manual

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Process Control

Limit Switch Mini-Switch LB 471

Hardware Manual

ID No. 39505 BA2

Rev. No.: 03 17. Nov. 2015 Soft. Version: 1.12 or higher

detect and identify

User’s Guide

The units supplied should not be repaired by anyone other than Berthold Service engineers or technicians by Berthold. In case of operation trouble, please address to our central service department.

The complete user’s guide consists of two manuals, the hardware description and the software description.

The hardware manual comprises:

 mechanical components  assembly  electrical installation  radiation protection guidelines  technical data  electrical and mechanical drawings

The software manual comprises:

 operation of the evaluation unit  parameter description  basic setting  calibration  error messages

The present manual is the hardware description.

Subject to change in the course of further technical development.

Table of Contents

Page

Chapter 1. General Information 9

1.1 Use and Function 9

1.2 Target Group 9

1.3 Radiation Protection Courses 10

1.4 Definitions 10

1.5 Safekeeping of the User’s Guide 12

Chapter 2. Safety 13

2.1 Safety Concept 13

2.2 Symbols and Pictograms 13

2.3 Radiological Safety Officer 14

2.4 Duty of Notification 14

2.5 Radiation Protection Areas 15

2.5.1 Exclusion Areas 15

2.5.2 Controlled Areas 15

2.5.3 Monitoring Areas 16

2.6 Safety Installations 17

2.6.1 Source Shieldings 17

2.7 General Safety Instructions 19

2.8 Emergency Instructions 19

2.8.1 Theft Protection 20

Chapter 3. Functional Safety 21

3.1 Use and Function 21

3.2 Safety Function 22

3.3 Safety Requirement 22

3.4 Project Planning 22

3.5 Getting Started 24

3.6 Behavior during Operation and Malfunctions 28

3.7 Recurrent Performance Test 29

3.8 Safety-Technical Data 29

Chapter 4. Instrument Description 36

4.1 Function 36

4.2 Mini Switch LB 471 Versions 37

4.2.1 Type Code 39

4.3 Detectors 40

4.3.1 GM Detector 40

4.3.2 NaI Detector 41

4.3.3 Super-Sens Detector 43

Chapter 5. Installation 45

5.1 Transport to the Installation Site 45

5.1.1 Transporting Detector and Evaluation Unit 45

5.1.2 Transport Shielding with Source 45

Mini-Switch LB 471

Table of Contents

5.1.3 Temporary Storage of Sources 46

5.1.4 Installation Site 46

5.1.5 Unpacking and Cleaning System Parts 46

5.2 Installing the Detector 47

5.2.1 Fastening Clamps for GM Detectors and NaI Counters 48

5.2.2 Stainless Steel Detector Holder (Alternative) 48

5.2.3 Installation of the GM Detector 49

5.2.4 Installation of the GM Detector 51

5.2.5 Installation of Super-Sens with Axial Irradiation 54

5.2.6 Installation of Super-Sens with Radial Irradiation 56

Chapter 6. Water Cooling 59

6.1 Subsequent Installation of Water Cooling (Option) 61

6.1.1 Water Cooling for NaI Detector with Collimator 62

6.1.2 Water Cooling for NaI Detector with Collimator 64

6.1.3 Water Cooling for GM Detector 65

6.2 Amount of Cooling Water Required 66

Chapter 7. Shielding Installation 67

7.1 General Installation Instructions 67

7.2 Installation Proposal for Shielding 68

7.3 Pneumatic Shielding Shutter (Option) 70

Chapter 8. Electrical Installation 71

8.1 Connecting Evaluation Unit and Detector 72

8.1.1 Pin Assignment of Terminal Block 73

8.1.2 Installing NaI Detector or Super-Sens 74

8.1.3 Installing the GM Detector 75

8.2 Digital In-/Outputs 77

8.2.1 Relays 77

8.2.2 Digital Input 77

8.3 Connecting the Evaluation Unit to Power 78

Chapter 9. Maintenance 79

9.1 Malfunctions 79

9.2 Replacing Fuses 79

9.3 Replacing the Evaluation Unit 80

9.4 Repairing the Detector 80

9.4.1 Dismantling the NaI Detector 81

9.4.2 Checking the Crystal-Multiplier Combination 84

9.4.3 Assembly of Crystal-Multiplier Combination 85

9.4.4 Plateau Measurement 86

9.4.5 Dismantling the GM Detector 87

9.5 Replacing the Source 88

9.5.1 Replacing the Source 90

9.6 Customer’s Service 92

9.6.1 Sending in the Electronics 93

9.6.2 Sending in Source and Shielding 94

Mini-Switch LB 471

Table of Contents

Chapter 10. Servicing the Shielding 95

10.1 Checking Shielding and Source 95

10.1.1 Testing the Locking Mechanism 95

10.2 Leak Test 96

10.2.1 Leak Test Documentation 96

10.2.2 Performing a Wipe Test 97

Chapter 11. Radiation Protection 99

11.1 Basics and Directives 99

11.2 Radiation Dose Calculations 101

11.3 Calculation with a given Dose Rate 101

11.4 Activity-based Calculation 102

Chapter 12. Disposal 103

Chapter 13. Technical Data 105

13.1 Evaluation Unit 105

13.2 Detectors 106

13.3 Shieldings 108

13.4 Pneumatic Locking Drive 108

Chapter 14. Certificates 109

14.1 ATEX Certificate for Evaluation Unit LB 4710-XXX 109

14.2 ATEX Certificate NaI Detector 113

14.3 ATEX Certificate GM Detector 117

14.4 EC Declaration of Conformity 119

Chapter 15. Technical Drawings 121

15.1 NaI Detector 121

15.2 GM Detector 122

15.2.1 Fastening Clamps 123

15.2.2 Detector Holder for GM Detector and NaI Counter 124

15.3 Super-Sens Detectors 125

15.4 Point Source Shielding LB 744X 131

15.5 Dimensions of the Evaluation Unit 134

15.5.1 19" Rack 134

15.5.2 Wall Housing 135

15.5.3 Cassette 136

15.6 Connection Diagrams 137

15.6.1 19" Rack 137

15.6.2 Wall Housing 138

15.6.3 Cassette 139

15.6.4 Connection Diagram for Power Supply Unit in 19" Rack 140

Mini-Switch LB 471

Chapter 1 General Information

Qualification

Training

Chapter 1. General Information

1.1 Use and Function

The limit switch system LB 471 Mini Switch has been designed for monitoring and detection of levels in containers and pipelines. Licensed as an “overflow protection device for containers storing liquids that are hazardous to waters” in accordance with the Water Resources Act, the system may also be used as overflow protection device. Beyond this scope, each application is considered as not being in compliance with the law and may result in severe personal injury or property damage. BERTHOLD TECHNOLOGIES does not assume any liability for this kind of injuries or damage.

1.2 Target Group

This user’s guide has been written for operating, assembly and

service personnel.

The system may only be assembled, serviced and maintained by authorized and trained persons. Any modification of the settings may only be carried out by persons who are familiar with the function of the system. Persons working with ionizing radiation must be familiar with the rules of radiation protection and adequate work techniques.

Personnel have to be specially trained and informed about possible hazards. Detailed knowledge of this user’s guide and careful observation of the instructions contained therein is an essential prerequisite. Each staff member has to know the major rule of the “ALARA principle” (as low as reasonably achievable). BERTHOLD TECHNOLOGIES is offering appropriate training courses. Depending on the participant’s professional qualifications, two kinds of training can be chosen:

Mini-Switch LB 471

Chapter 1 General Information

Automatic

Some parameters can either be set to the automatic or manual mode. In the automatic mode the value is calculated using a formula. Enter -1 to enable the automatic mode. The inverted C in the top row indicates whether a parameter has been set to automatic.

EVU

Evaluation Unit

Edit

Change value

Edit mode

In this mode, a value can be changed. Not every parameter can be changed since some parameters are only used as display values. Editable Parameters can be set to the edit mode with the “Enter” button. In the edit mode the cursor positioned over a digit is flashing.

GM detector

Detector with Geiger-Müller counter tube

NaI detector

NaI = sodium iodine crystal = scintillator Scintillation detectors are very sensitive to Gamma radiation. See pages 40 and 121.

Super-Sens detector

Detector which is highly sensitive to Gamma radiation with large-volume plastic scintillator 150x150mm See pages 43 and 125.

Limit value

Count rate or percentage value upon reaching the measurement level

1.3 Radiation Protection Courses

 Special course in radiation protection

(Duration: 2 days) This course is needed if the participant has not yet received any radiation protection training. A successfully completed course has a validity of 5 years.

 Refreshing course in radiation protection

(Duration: 1 day) All persons who have already successfully completed the special course may refresh their special knowledge with this course (Radiation Protection Ordinance of August 1, 2001). A successfully refreshing course has a validity of 5 years.

1.4 Definitions

Mini-Switch LB 471

Chapter 1 General Information

Detector high voltage

Cassette

Case (7 TE) into which the evaluation unit LB 4710 is installed, so it can be used in any 19" rack

Empty

Level below limit value.

Empty count rate

Count rate with empty container

Manual

Some parameters can either be set to the automatic or manual mode. For the manual mode you have to enter a fixed value in the respective parameters.

Nuclide / Isotope

Type of radiation source: Cobalt-60 (Co-60) or Cesium-137 (Cs-137) for level measurements.

Zero count rate

Count rate caused by natural environmental radiation.

Parameters

A value stored under a certain code.

Timeout

Time after which an automatic reset is performed.

Full

Level below limit value.

Full count rate

Count rate with full container.

Count rate

Value of counts relative to one second.

cps

Count rate unit: Counts per second.

Read in count rate

A process that is started by the user in order to determine the average value of the count rate at the respective level. This count rate is needed to calibrate the measurement. The count rate is averaged over a certain time (standard 60 s) to exclude statistical and process-immanent fluctuations.

Factory setting

All parameters have been preset by the manufacturer using standard values. In most cases this simplifies calibration of the instrument significantly. Despite factory setting, calibration al-

ways has to be performed.

mSv

Dose rate unit Millisievert

Mini-Switch LB 471

Chapter 1 General Information

MBq

Mega-Becquerel This unit indicates the source activity. Each Bq corresponds to one decay per second.. 1 MBq = one million decays

mCi

Milli-Curie This unit is also used for the activity of a source. However, this unit has been replaced by the unit MBq (1mCi = 37 MBq)

Note!

This user’s guide always has to be available at a fixed place. The

personnel have to be informed about this place. Any time the device is used by another operator and whenever there is a change in ownership of the device, the user’s guide has to be given to the new operator or owner.

1.5 Safekeeping of the User’s Guide

Mini-Switch LB 471

Chapter 2 Safety

Danger!

Possible danger for life and health hazard

Caution!

Possible hazard Minor personal injuries

Warning!

Possible hazard Property damages

Note!

Tips for application and useful information

Chapter 2. Safety

2.1 Safety Concept

The state-of-the-art system is designed in accordance with accepted safety rules to ensure the greatest possible on-the-job safety. To rule out health hazards when handling radioactive substances, limit values stating the highest acceptable radiation exposure of the operating personnel have been defined on an international level. These limits have to be observed when designing shieldings and planning the configuration of the measuring system at the measurement point.

2.2 Symbols and Pictograms

The following symbols identify safety instructions in this user’s

guide:

The safety instructions are supplemented by explanatory pictograms, for example:

Mini-Switch LB 471

Chapter 2 Safety

Caution!

Radioactivity! In case of suspected damage to the shielding, the radiological safety officer has to be informed immediately. Further steps can be taken in consultation with BERTHOLD TECHNOLOGIES.

2.3 Radiological Safety Officer

To ensure proper handling and the observance of the statutory requirements the operating company has to appoint a radiological safety officer who is in charge of all radiation protection issues in connection with the measuring system. The radiological safety officer has to:

 monitor working with the radiometric measuring system  draw up a plan for the organization of radiation protection  monitor compliance with the regulations of the Radiation Pro-

tection Ordinance

 issue directives and carry out training and instruction of the

employees

 get on-site information on the situation and takes appropriate

actions immediately if operation problems have occurred

 cooperates with the work’s council or the personnel office and

qualified personnel for on-the-job safety, advises and informs them on important radiation protection issues.

2.4 Duty of Notification

Mini-Switch LB 471

Chapter 2 Safety

Caution!

Radioactivity! The radiation protection directives have to be observed. Exclusion areas have to be protected such that nobody has unchecked access to these areas – not even with single body parts. This has to be ensured through constructive measures, for example by protective covers.

2.5 Radiation Protection Areas

Radiation protection areas define the boundaries around a radiation source. The maximum dose rate defines the limit. We distinguish three radiation protection areas:

2.5.1 Exclusion Areas

Exclusion areas are areas in which the local dose rate may be exceed 3 Millisievert (mSv) per hour. These areas have to be protected such that nobody has unchecked access to these areas – not even with single body parts. Actually, these areas can occur only in the active beam in the direct vicinity of the shielding.

2.5.2 Controlled Areas

Controlled areas are areas in which persons in one calendar year may receive an effective dose of more than 6 mSv if they stay in this area 40 hours a week and 50 weeks per calendar year. Based on this, the calculated maximum dose rate is 3 µSv/h. These areas should be planned such that accessibility is virtually not possible or that the required safety fences can be installed easily. If con- trolled areas are accessible they have to be secured. Moreover, they have to be identified clearly and permanently by a radiation danger sign and the comment “Controlled Area”. Persons may access controlled areas only to carry out maintenance work for the operations going on inside this area (§ 37). Body doses have to be calculated or personal doses have to be measured. The authorities may permit exceptions from the demarcation and identification duty, provided individuals or the general population are not endangered. Higher limit values are admissible if reliable in-

formation is provided that the person affected stays within the controlled area for a shorter period of time.

Mini-Switch LB 471

Chapter 2 Safety

Caution!

Radioactivity! The radiation protection directives have to be observed. Controlled areas outside the shielding have to be identified and secured if they are accessible.

2.5.3 Monitoring Areas

Monitoring areas are operation areas which do not belong to the controlled area. In these areas, a person may receive an effective dose of more than 1 mSv in one calendar year.

The monitoring area starts at the controlled area. It is an area in which persons staying permanently in this area may be exposed to a radiation level of more than 1 mSv in one calendar year. For a stay of 40 hours per week and 50 weeks per year the area is between the dose rate limit values of 3 µSv/h and 0.5 µSv/h. It has to be ensured that persons are not exposed to a dose exceeding 1 mSv per year, taking into account the actual time they stay in this area. This means that no permanent work place may be set up in this area.

Mini-Switch LB 471

Chapter 2 Safety

Caution!

Radioactivity! The shielding with the source installed may be taken into operation by specially licensed persons who have been trained on handling radioactive materials only after consultation and coordination with the radiological safety officer. The radiation exit channel must only be opened by authorized persons after consultation with the radiological safety officer. Modification of or tampering with the shielding construction are prohibited.



Shielding



Locking core



Radiation channel

Point sources 

Source holder



Lever



Padlock



Cover plate front

Source

Shielding

Figure 1:

Point source shielding

radiation channel open

Sectional drawing

  





  

2.6 Safety Installations

2.6.1 Source Shieldings

Co-60 or Cs-137 point sources  are used for the system. They are tightly welded into a sturdy stainless steel capsule, so that the

radioactive substance cannot escape and contamination is prevented. The capsule with the source  is fixed on a holder  and installed into the shielding.

The shielding consists of a lead cylinder with radiation exit channel

, surrounded by a steel jacket. The locking core  is fixed to a



lever . The padlock  secures the open / closed position and protects the source against unauthorized removal.

When turning the lever , the locking core is rotated as well and the radiation exit channel is opened towards the detector. The arrow on the lever  is pointing towards “OPEN”.

Mini-Switch LB 471

Chapter 2 Safety



Lever with arrow



Padlock



Cover plate rear



Source number



Activity



Isotope



Source manufacturing

date



Dose rate in

1m distance



Effective shielding

thickness



Shielding material



Type of shielding



Shielding manufacturer

Figure 2: Shielding

- view of lock

Type label

Figure 3:

Type label

on shielding







Strahler-Nr.:

1234 - 11- 9 4

MBq

Co-60

400

Abschirmung

Datum

12. 11.94

Dosisleistung in 1m Abstand

 Sv/h

MODEL LB 7440

Bad Wildbad D-75323











  



The radiation exit channel has to be closed during transport, assembly and while carrying out work on the container. The arrow on the lever is then pointing to “CLOSED”.

The lever or the locking core is secured by a padlock  in the “OPEN” and in the “CLOSED” position.

Shielding, radiation type, isotope and activity have to be selected for each measuring configuration such that the internationally permissible dose rate limits will not be exceeded.

The source and shielding version is documented in the supplied technical source documentation and on the type label on the shielding.

Mini-Switch LB 471

Chapter 2 Safety

Caution!

The safety instructions in this user’s guide have to be observed without fail. All laws, directives, accident prevention regulations and generally accepted safety regulations have to be complied with! The system may be used only in technically good order and only for contractual use! Only persons may work with the system who have been authorized to do this and who have the proper qualification and have received the necessary instructions! Installations and modifications on the system which may affect the operational safety are prohibited!

Danger!

Hazard due to radiation damages. Never touch the source with your hands!

2.7 General Safety Instructions

2.8 Emergency Instructions

The following basic principles are indispensable for health and safety: Time, distance and shielding. In an emergency, the following provisions have to be taken:

 Restrict access to this area, identify radiation protection areas.  Check the function of the shielding and measure the dose rate.  Localize the source.  Document the event and, if possible, estimate the potential

radiation exposure of the persons involved.

 Report event to BERTHOLD TECHNOLOGIES.  In case of loss of radiation sources, the regulatory agency has

to be notified immediately.

 In case of suspected damage to the source capsule the follow-

ing issues have to be taken into consideration:

 Grasp source with a tool (e.g. a pair of pliers or tweezers) and

put both (source and tool) into a plastic bag.

 Place plastic bag behind an auxiliary shielding (concrete wall,

steel or lead plate).

 Check if environment is free of contamination.  If a source has any leaks or if you suspect that the permissible

dose has been exceeded, the regulatory agency has to be notified immediately.

Mini-Switch LB 471

Chapter 2 Safety

2.8.1 Theft Protection

Radioactive substances or facilities containing radioactive substances have to be secured such that they are protected against access by unauthorized persons. If you discover that radioactive substances are missing, you have to notify the radiological safety officer and the regulatory agency. In case of theft, the police have to be informed.

Please see Chapter 11 for more information on radiation protection.

Mini-Switch LB 471

Chapter 3 Functional Safety



Source



Detector



Evaluation unit

Figure 4:

Measuring system







2 wires

Chapter 3. Functional Safety

3.1 Use and Function

The LB 471 Mini Switch is employed for monitoring and detection of the limit levels of liquids and bulk material in containers and pipelines.

The measuring system can be employed for the detection and indication of maximum levels (overflow protection) and minimum levels (protection against dry running) and fulfills the requirements regarding:

 Explosion protection (depending on version and category),  Water Resources Act (overflow protection device for containers

storing liquids that are hazardous to waters),

 Electromagnetic compatibility according to EN 61326 and Na-

mur NE 21.

If the device is employed in safety-relevant systems (functional safety according to IEC 61508/61511), all information in this User's Manual has to be observed. In particular, the safetytechnical data in section 3.8 apply only to the application of the system in the operating mode with low demand mode and taking into account the information in this manual. Beyond this scope, each application is considered as not being in compliance with the law and may result in severe personal injury or property damage. BERTHOLD TECHNOLOGIES does not assume any liability for this kind of injuries or damage.

Mini-Switch LB 471

Chapter 3 Functional Safety

Safety integrity

level

Operating mode with

low demand rate

Operating mode with high

or continuous demand rate

SIL

PFD

avg

PFH

≥10-5 to <10-4

≥10-9 to <10-8

≥10-4 to <10-3

≥10-8 to <10-7

≥10-3 to <10-2

≥10-7 to <10-6

≥10-2 to <10-1

≥10-6 to <10-5

Safe failure fraction

Hardware fault tolerance

SFF

HFT = 0

HFT = 1

HFT = 2

none: <60%

not allowed

SIL 1

SIL 2

low: 60% to <90%

SIL 1

SIL 2

SIL 3

medium: 90% to <99%

SIL 2

SIL 3

high: ≥99%

SIL 3

General instructions and restrictions

3.2 Safety Function

The safety function of the measuring system comprises the detection and indication of changes in the count rate of the detectors caused by the presence of product being measured in the measuring path between radiation source and measuring system. The safe status is dependent on the mode of operation:

 Maximum level (overflow protection): Product between radia-

tion source and detector -> low count rate

 Minimum level (protection against running dry): No product

between radiation source and detector -> high count rate

3.3 Safety Requirement

3.4 Project Planning

 Please make sure that the measuring system will be used in

accordance with its designated function.

 The application-specific limits have to be observed and the

specifications must not be exceeded. See also the technical data and ambient conditions in the User’s Manual.

 The fault tolerance time of the overall system must be greater

than the reaction time of the measuring system.

 The relay contacts have to be protected by a 1A fuse.  The digital inputs 1 and 2 must not be closed in case of a safe-

ty-related application.

Mini-Switch LB 471

Chapter 3 Functional Safety

Assumptions

Safe state and fault description

 Interfering radiation, e.g. due to welding seam tests, is largely

identified and signaled by the measurement. However, in some situations it is conceivable that the intensity of the interfering radiation will increase the radiation level at the detector only slightly, so that no alarm is triggered or not in due time. Therefore, the facility always has to be informed as soon as a welding seam test is carried out in the environment of the facility in which the measurement is employed. In this case, suitable safety precautions have to be taken.

 Interfering radiation from adjacent measuring points has to be

avoided.

The FMEDA (Failure Mode Effects and Diagnostics Analysis) is based on the following assumptions:

 The failure rates are constant over the service life of the de-

vice.

 The following is not taken into consideration:

external power supply failure rates multiple errors operating mode as minimum level switch

 The mean ambient temperature during the operating time is

40°C.

 The environmental conditions correspond to those of an aver-

age industrial environment.

 The working life of the components is between 8 and 12 years.  The time to repair (replacement of the measuring system) after

a fault protected from interference is eight hours (MTTR = 8h).

If the demand rate is not more than once a year, the measuring system may be operated as a safety-relevant sub-system in the operating mode with low demand rate (IEC 61508-4, 3.5.12).

Numerical values see section “Safety-Technical Data”.

The fail-safe state is reached when the current output indicates the following values.

A safe failure is defined as a failure that causes the measuring system to go to the defined fail-safe state without a demand from the process.

A dangerous undetected failure is present if the measuring system, following a demand from the process, does not go to the defined fail-safe state.

Mini-Switch LB 471

Chapter 3 Functional Safety

3.5 Getting Started

The conditions at the facility affect the safety of the measuring system. Therefore, the mounting and installation instructions in the User’s Manual have to be observed. In particular, the correct setting of the parameters has to be ensured. For more information on the parameters and on getting started, please refer to the User’s Manual LB 471 ID No. 39505BA2. The device may be operated as safety-relevant only in the professional mode.

Reset

Keep Clear button pushed and turn the power supply on.



 The device is reset to factory setting.

Basic parameter setting

Set parameters according to the following parameter list.



The order in which the parameters have to be set is shown in the last column. Fields that are not numbered in this column are display parameters or parameters that remain on factory setting. If the Value column includes data, then you have to enter this data exactly. If no data has been entered in the Value column but a number has been entered in the last column, then the value of the parameter has to be adapted to the given measurement situation. However, the value has to be adapted only if this is required by the measurement situation.

Mini-Switch LB 471

Chapter 3 Functional Safety

Code

no.

Designation

Value range

Factory

setting

Value

Order

Password

0000 - 9999

Year

1970 - 2099

Current

year

Month / Day

01.01-12.31

Current

date

Hour / Minute

00.00-23.59

Current

time

4 04

Operation mode

Standard/Professional

0 - 1

Detector code

0 - 99

Nuclide

0=Co60, 1=Cs-137

0 - 1

Automatic password

protection

0 - 9999

Warning relay as

second alarm relay

0 – 1 10 – 100

Alarm relay follows

the error relay

0 - 1

Reading (%)

-999 - 9999

Display

Average count rate

0 - 999.9

Display

Time constant (s)

0,1 – 999,9

-1

Live count rate

0 - 999.9

Display

Maximum time constant (s)

0 - 999

999

Standard reading

10 - 11

Max. or min. limit

value switch

0=Max, 1=Min

0 - 1

Switching threshold (%)

0 - 100

-1

Switching threshold in (cps)

0 - 999.9

-1

Hysteresis (%)

0 - 999

-1

Empty count rate (no input)

0 - 999.9

Display

Full count rate (no input)

0 - 999.9

Display

Zero count rate (no input)

0 - 9.999

Display

Empty count rate

0 - 999.9

20 GMZ

300 FSK

Full count rate

0 - 999.9

-1

Zero count rate

0 - 9.999

Depending

on detector

code

Measuring path (in mm)

0 - 9999

Gas density (kg/m³)

0 - 9999

Bulk density (kg/m³)

0 - 9999

Compute

35.01–35.08

Display

Counting time for

calibration (s)

5 - 600

Bulk cone diameter (mm)

0 - 9999

Table 1:

Code table

for professional mode

Mini-Switch LB 471

Chapter 3 Functional Safety

Code

no.

Designation

Value range

Factory

setting

Value

Order

Half-value layers

1 - 9

Interference radiation

detection

0 - 1

Waiting time after

interference radiation

0 - 999

Signaling interference

radiation

0 - 2

Signaling unlocked

0 - 2

Signaling minor errors

0 - 2

Signaling excess temp.

Detector (only FSK detector)

0 - 2

Temperature threshold

detector (only FSK)

0 - 99

Signaling excess temp.

EVU

0 - 2

Temperature threshold EVU

0 - 99

≤50

Limit switch software

1.00 - 9.99

Version

Detector software

(only FSK)

1.00 - 9.99

Display

Detector temperature °C

(only FSK detector)

-40 - 80

Display

Detector high voltage

(only FSK)

500 - 1300

-1

detector HV start value

(only FSK)

500 - 1300

HV default

Source replacement

00.00- 99.12

-1

Evaluation unit electronics

temperature

-100 - 200

Display

Test pulse generator

0 - 999.9

Test error relay

0 - 2

Test alarm relay

0 - 2

Test warning relay

0 - 2

Test display

Test keyboard

Status digital in

00.00 - 01.01

Display

HV max for plateau

measurement

500 - 1300

1000

Detector plateau

measurement

(only FSK)

0 - 5

Error log

0 - 1

Revision log

0 - 1

Save & Load / Reset

0 - 99

Mini-Switch LB 471

Chapter 3 Functional Safety

Empty calibration

 The level must be at least 50 mm below the limit level. The

radiation channel of the shielding is open. Push the “Cal” button for 3 seconds



 The empty count rate is read in.

At the end of the measuring time, code 30 is displayed and the read-in empty count rate.

Full calibration

 The level must be at least 50 mm above the limit level.

If this is not possible, you may also close the source shielding. If only the source shielding is closed to carry out the full calibration, then you have to keep in mind:

- Make sure that the absorption of the closed shielding nearly corresponds to the absorption of the product. If in doubt, please contact BERTHOLD TECHNOLOGIES or your local representative.

- Typically, you will lose some dynamics in the measurement, which results in a higher time constant.

Select code 31.



Push the Enter button Push the Cal button.

 The full count rate is read in.

At the end of the measuring time, code 31 is displayed and the read-in full count rate.

Calibration

Select code 36.



Push the Cal button.

 A checkmark and the digits 0000 confirms that the calibra-

tion was successful. If an error message is display, the error has to be removed as described in the User's Manual and in the error list; then the calibration has to be carried out once more.

Test

Write down the empty and full count rate in code 30 and



code 31. Select code 60. Enter the full count rate in code 60.

 The measurement must show 0% in code 10.

If not, check the calibration. Select code 60.



Enter the full count rate in code 60.

The measurement must show 100% in code 10.

If not, check the calibration.

Mini-Switch LB 471

Chapter 3 Functional Safety

Function check

 Level is at least 50mm below the limit level when the radia-

tion channel of the shielding is open.

 The measured value in code 10 has to fluctuate around 0%.

The alarm output must not trigger an alarm.

 Increase the level above the limit level or close the shield-

ing.

 The measured value in code 10 has to fluctuate around

100%. The alarm output must indicate an alarm and must not switch back anymore.

Password

Enter a password in code 00.



 This rules out data manipulation by unauthorized persons.

The error relay switches to normal only when the password has been entered and no error message is output.

The calibration is now finished and the measurement has been taken into operation.

3.6 Behavior during Operation and

Malfunctions

 The following parameter are automatically adjusted in the

course of operation relative to the decay compensation; therefore, their values may change: code 12 and code 18 – 31

 If the operation is changed, please observe the safety func-

tions.

 Malfunctions that may occur are described in the User’s Manu-

al.

 If failures have been detected or malfunctions are reported,

you have to take the entire measuring system out of service and keep the process in a safe state through other measures.

 Replacement of the measuring system is rather simple; it is

described in the User’s Manual.

 If parts are replaced as a result of a detected failure, please

inform BERTHOLD TECHNOLOGIES (including failure description).

 If modifications in the product, the gas pressure, or the con-

struction of the tank in the area of the radiation path are carried out, the measurement has to be calibrated again.

Mini-Switch LB 471

Chapter 3 Functional Safety

λsd

230 Fit

safe detected failure (1 FIT = failure/109h)

λsu

536 Fit

safe undetected failure

λdd

210 Fit

dangerous detected failure

λdu

83 Fit

dangerous undetected failure

SFF

>92%

Safe Failure Fraction

Reaction

Failure reaction time

1.5 sec

max. service life of the measuring system for the safety function.

7 years

General data

3.7 Recurrent Performance Test

The recurrent performance test is used to check the safety function to uncover possibly undetected dangerous failure. The operational capability of the measuring system has to be checked in adequate intervals. It is in the responsibility of the operator to select the type of test and the proof test interval. The intervals are dependent on the PFD Technical Data” (see also FMEDA Report). The test has to be carried out such that the proper safety function will be proven through interaction of all components. This is the case when the level is controlled within the scope of a filling. If a filling is not feasible, the measuring system has to be triggered to respond by suitable simulation of the level or of the physical measurement effect. The methods and procedures used in the tests have to be named and their degree of suitability has to be specified. The tests have to be documented. If the function check is negative, you have to take the entire measuring system out of service and keep the process in a safe state through other measures.

value defined in the table and chart in the section “Safety-

avg

3.8 Safety-Technical Data

Failure rates of the electronics were determined through FMEDA according to IEC 61508. Calculations are based on the component failure rates according to SN 29500. All numerical values refer to an average ambient temperature of +40°C (104°F) during the operating period. Calculations are further based on the information provided in chapter 3.4 Project Planning.

Mini-Switch LB 471

Chapter 3 Functional Safety

PFD

avg

Proof

= 1 year

Proof

= 2 years

Proof

= 5 years

Proof

= 10 years

<0.036 x 10

-2

<0.073 x 10

-2

<0.180 x 10

-2

<0.360 x 10-2

PFD

avg

Proof

= 1 year

Proof

= 2 years

Proof

= 5 years

Proof

= 10 years

<1.8 x 10

-5

<3.7 x 10

-5

<9.5 x 10

-5

<20 x 10-5

PFD

avg

Proof

= 1 year

Proof

= 2 years

Proof

= 5 years

Proof

= 10 years

<3.7 x 10

-5

<7.3 x 10

-5

<19 x 10

-5

<38 x 10-5

Detector

Evaluation units

Container

Shielding with source

Detectors

Evaluation units

Container

Shielding with source

Single channel architecture

HFT = 0 (Hardware Fault Tolerance)

Two-channel architecture

HFT = 1 (Hardware Fault Tolerance)

1) for Common cause ß=5%

2) for Common cause ß=10%

Mini-Switch LB 471

Chapter 3 Functional Safety

Time-dependent trend of PFD

avg

PFD

avg

Proof

1 5 10 1 2

The time trend of PVD

is nearly linear to the operating time in

avg

the period up to 10 years. The above mentioned values apply only to the T

interval, according to which a recurrent performance

Proof

check has to be carried out.

Time-dependent trend of PFD

avg

Mini-Switch LB 471

Chapter 3 Functional Safety

Mini-Switch LB 471

Chapter 3 Functional Safety

Mini-Switch LB 471

Chapter 3 Functional Safety

Mini-Switch LB 471

Chapter 4 Instrument Description

Figure 5:

Measuring system







2 wires

Chapter 4. Instrument Description

4.1 Function

The limit switch system Mini Switch LB 471 is working on the basis of non-contact Gamma absorption measurement. The system can also be employed with heavy process conditions and aggressive media. In order to obtain an optimum measurement effect at minimum source activity the best measurement geometry is calculated for the respective measuring point and the source is designed on the basis of this calculation. The system comprises three major components:

 shielding with radiation source   Detector   evaluation unit .

The shielded radiation source  is installed outside the container on the level to be measured. A detector  is installed on the opposite side of the container. The evaluation unit  is connected to

the detector by a 2-wire line. If the level of the medium inside the container comes up to the level of the detector or the source, the radiation is absorbed and the evaluation unit sends a corresponding signal. The following radiation sources are used:

Mini-Switch LB 471

Chapter 4 Instrument Description

Caution!

Observe explosion protection! Intrinsically safe and not intrinsically safe systems must not be mixed, neither in a 19" rack nor in a wall housing.

In a 19" rack

 Co-60 has a relatively high energy of 1.17 or 1.33 MeV and is

used on very thick pipeline or container walls. Its half-life time is 5.27 years.

 In most cases, Cs-137 with an energy of 0.660 MeV is ade-

quate to irradiate common pipeline or container walls. Its halflife time of Cs-137 is around 30 years.

Due to the lower energy, operating expenses for shielding a Cs-137 source are lower than for Co-60.

4.2 Mini Switch LB 471 Versions

The Mini Switch LB 471 can either be delivered in a 19" rack, in a wall housing or in a cassette.

The 19" rack can be mixed with limit switches for GM detectors and fitted for NaI detectors. The 19" rack includes a back plane. A filter module is used (for max. 19 limit switch modules) for 24V AC/DC supply. It includes:

 one mains switch  on mains On LED  two fuses (see Technical Data on page 105)  additional filter section

A 85W transformer module is used (for max. 18 limit switch modules) for 115/230V supply. In addition to the filter module, the transformer module has:

 a transformer with voltage selector switch 115V/230V

Mini-Switch LB 471

Chapter 4 Instrument Description

for any 19" rack

In a wall housing

As cassette

Front view Side view

The wall housing can be mixed with limit switches for GM detectors and fitted for NaI detectors. The wall housing includes a back plane. A filter module is used for 24 V AC/DC supply. It includes:

 one mains switch  on mains On LED  two fuses (see Technical Data on page 105)  additional filter section

For 115/230V a 17W transformer module is installed. In addition to the filter module, the transformer module has:

 a transformer with voltage selector switch 115V/230V

The evaluation unit is installed in a cassette with 7TE. Thus, it can be used in any 19" rack without back plane. A 32-pole terminal block is available to connect the wires.

Mini-Switch LB 471

Chapter 4 Instrument Description

Type

Detector

Det. connection

Version

LB4710-050

GM detector

II (2) G [EEx ib] IIC and I M2 [EEx ib] I

19" rack / wall housing

LB4710-060

II (2) G [EEx ib] IIC and I M2 [EEx ib] I

Cassette

LB4710-080

not Ex

19" rack / wall housing

LB4710-090

not Ex

Cassette

LB4710-150

NaI detector

Super-Sens

II (2) G [EEx ib] IIC and I M2 [EEx ib] I

19" rack / wall housing

LB4710-160

II (2) G [EEx ib] IIC and I M2 [EEx ib] I

Cassette

LB4710-180

not Ex

19" rack / wall housing

LB4710-190

not Ex

Cassette

Detector

LB 471 Limit switch module

GM detector

LB 4710-0XX

NaI detector or Super-Sens

LB 4710-1XX

Type code evaluation unit

4.2.1 Type Code

The following table shows the type code for the different versions of the evaluation unit LB 471.

Depending on the detector type you have to combine the following limit switch modules:

Mini-Switch LB 471

Chapter 4 Instrument Description

Type

Number of

counter tubes

Ex-protection SZ5 GHS 3171-1Gd

pressure-proof casing

SZ5 GHS 3171-2Gd

pressure-proof casing

SZ5 GHS 3171-1Gi

intrinsically safe

SZ5 GHS 3171-2Gi

intrinsically safe

GHS 3172-1

GHS 3172-2

GM detector types

4.3 Detectors

The detector converts the Gamma quanta emitted by the source into electrical pulses and passed them on to the evaluation unit. All components are installed together with the high voltage generation in a sturdy cylindrical stainless steel case with integrated connection box. Different versions are available which are selected in accordance with physical, radiation protection or economical considerations in the project planning phase.

4.3.1 GM Detector

Depending on the operation conditions, the GM detector is equipped with one halogen counter tube for standard applications or with two halogen counter tubes for special applications for short switching times or to reduce a high source activity. GM detectors are installed with the respective electronics including high voltage generation and pulse amplification in a stainless steel case.

The protection type is IP 65.

The connection is made in the integrated connection room with two wires. The maximum cable length is 1000 m at a cable crosssection ≥1.0 mm2.

Mini-Switch LB 471

Chapter 4 Instrument Description

LB 4700

0 standard temperature range 1 enhanced temperature range

11 50/50 NaI point detector 12 50/50 NaI point detector + water cooling 1A 50/60 polymer 1B 50/60 polymer + water cooling

2A 500 mm 2B 500 mm 2E 1000 mm 2F 1000 mm 2I 1500 mm 2J 1500 mm 2K 2000 mm 2L 2000 mm

0 without a axial r sidewise

00 without Ex approval 1A ATEX/IECEx; Ex-d/e/t IA ATEX/IECEx; Ex-d/i/t

47 Ex 57 non Ex

4.3.2 NaI Detector

The detector material is an artificially manufactured and specially dotted NaI crystal. Different crystal sizes are available, depending on the required sensitivity. Installed in a sturdy stainless steel case, the detector is protected from normal environmental strain which may occur in industrial applications.

Mini-Switch LB 471

Chapter 4 Instrument Description

LB 44xx

E Europe / ATEX U USA / FM C CANADA / CSA J JAPAN / TIIS Z FM / CSA K Korea

Terminal Compartment

x without certificate d Ex-e (exception USA/FM and CSA = flame proofed) i Ex-i

Protection Type

G Gas-Ex S Dust-Ex M Mining-Ex

Irradiation

x without collimator a axial r side irradiation 66° s side irradiation 90°

Cable Entry

0 sidewise 1 axial

Point Detector

Rod Detector

1 25/25 1 500 mm 2 40/35 2 750 mm 3 50/50 3 1000 mm 4 150/150 Plastic 4 1250 mm 5 40/5 5 1500 mm 6 44/5 6 2000 mm

Water Cooling

0 without 1 with

0 point-detector 1 point-detector 2 point-detector 3 point-detector 5 rod-detector

4 Ex 5 Non Ex

Mini-Switch LB 471

Chapter 4 Instrument Description

Standard Gas Ex: EEx de LB 4430-04-0a-Gd-E

axial irradiation

LB 4430-14-0a-Gd-E

with WC, axial irradiation

LB 4431-04-0s-Gd-E

lateral irradiation. 90°

LB 4431-04-0r-Gd- E

lateral irradiation. 66°

LB 4431-14-0s-Gd-E

with WC, lateral irradiation 90°

LB 4431-14-0r-Gd-E

with WC, lateral irradiation 66°

Intrinsically safe, Gas Ex: EEx ib LB 4430-04-0a-Gi-E

axial irradiation.

LB 4430-14-0a-Gi-E

with WC, axial irradiation

LB 4431-04-0s-Gi-E

lateral irradiation 90°

LB 4431-04-0r-Gi-E

lateral irradiation 66°

LB 4431-14-0s-Gi-E

with WC, lateral irradiation 90°

LB 4431-14-0r-Gi-E

with WC, lateral irradiation 66°

Firedamp protection LB 4430-04-1a-Md-E

axial irradiation

LB 4431-04-1s-Md-E

lateral irradiation 90°

Firedamp protection: intrinsically safe LB 4430-04-1a-Mi-E

axial irradiation

LB 4431-04-1s-Mi-E

lateral irradiation 90°

not Ex LB 5430

axial irradiation

LB 5431

lateral irradiation 66°

Super-Sens detector types

4.3.3 Super-Sens Detector

The Super-Sens detector is extremely sensitive to Gamma radiation. The high sensitivity is achieved by using a 150x150 mm large plastic scintillator. It is provided with a lead shielding to reduce the zero count rate and to reduce interferences. Working with the Super-Sens detector allows you to reduce the required source activity significantly.

WC = water cooling

Mini-Switch LB 471

Chapter 5 Installation

Danger!

Risk of injury! When unloading heavy system parts, never step under floating loads! Only use tested separate lifting accessories matching the transport weights. Observe adequate safety margin. Wear hard hat and protective gloves.

Warning!

Risk of damage! System parts may get damaged during transport. Transport detector and evaluation unit in their original packing. Protect parts against vibrations.

Caution!

Radioactivity! The radiation protection directives have to be observed. Radioactive substances may be transported on public traffic routes only by persons in possession of the proper transport license! A source may be transported only in the shielding.

Chapter 5. Installation

5.1 Transport to the Installation Site

5.1.1 Transporting Detector and Evaluation Unit

Use the eyebolts for transporting the Super-Sens detectors.

5.1.2 Transport Shielding with Source

The shielding with the source inside can be lifted onto a palette by a fork-lift and transported to its destination. The shielding includes eyebolts for transportation by a crane.

Mini-Switch LB 471

Chapter 5 Installation

Danger!

Risk of injury and damage! Heavy system parts may fall down if not installed properly. The carrying capacity of the container walls or the holders must be adequate to install the source with shielding and the detector.

5.1.3 Temporary Storage of Sources

The operator has to take suitable provisions for intermediate storage of sources at the place of installation between the period from source delivery to the start of the installation work. A source may be stored only in a lockable room which is identified accordingly. Accessible controlled areas have to be identified and, if necessary, secured.

5.1.4 Installation Site

Free space must be foreseen at the installation site for:

 Freedom of motion for delivery of shielding, detector and eval-

uation unit

 Servicing and repair work, to install and dismantle parts.

The source with shielding and the detector are horizontally installed on the designated limit level on the outside of the container and outside a possibly installed heat insulation. Any special features at the measuring point have to be taken into account.

5.1.5 Unpacking and Cleaning System Parts

After unpacking, compare all parts with the packing list and check if the shipment is complete and shows any sign of damage. If necessary, you may have to clean parts. If you detect any damage, notify the forwarder and the manufacturer immediately.

Mini-Switch LB 471

Chapter 5 Installation

Warning!

Risk of damage! The detector may be damaged by heavy mechanical strain, vibrations and high temperatures. The detector has to be mounted free from vibrations. During installation and operation, the detector must not be exposed to mechanical strain. The ambient temperature must not exceed the values stated in the technical data section (see chapter 13.2). If the ambient temperature is higher, the detector has to be cooled. Appropriate water cooling jackets are available as extras. See also Chapter 6 Water Cooling and the technical drawings on pages 121 to 130. Direct exposure to sunlight is not permitted as this may lead to an unacceptable increase of the surface temperature. In these cases, you have to install a canopy top (see Figure 6).

Figure 6:

Detector with canopy top

canopy top

detector

5.2 Installing the Detector

Mark the level to be monitored at the container. Position the detector there in a horizontal line with the source. At the same time, the horizontal line is the limit level where the device is switching. Make sure that the radiation window of the detector is not covered by the holder. The distance to the surface of the container or the heat insulation should be approx 20 mm.

Mini-Switch LB 471

Chapter 5 Installation

Clamps for detector without water cooling

Clamps for detector with water cooling

ID-NO 31346 (1 set= 2 clamps)

ID-NO 31347 (1 set = 2 clamps)

Holder for detector complete

ID-NO 39246

Figure 7:

Clamp for GM detectors

and NaI detectors

Figure 8:

Detector holder

5.2.1 Fastening Clamps for GM Detectors and NaI

Counters

Stainless steel clamps are available to install the detector. The dimensions of the clamps are shown in the technical drawings in the Appendix. The technical drawing with dimensions is shown on page 123.

5.2.2 Stainless Steel Detector Holder

(Alternative)

A sturdy stainless steel holder may be used instead of clamps. The holder comprises an angle on which two clamps have already been installed. You can fix the holder on a bracket either with screws or through welding. Due to the plastic rings, the same holder may be used for detectors with or without water cooling. All metal parts of this holder are made of stainless steel. The technical drawing with dimensions is shown on page 124.

Mini-Switch LB 471

Chapter 5 Installation



Red marking strip for

counter tube position



Connection room

Figure 9:

Installation on container

GM detector

Figure 10:

Alternative installations





Radiation path

Bracket provided by customer

A B C

5.2.3 Installation of the GM Detector

Align the detector horizontally exactly on the level of the source. The red marking strip on the case shows the position of the counter tube in the detector. The counter tube must not be covered by the holder or by clamps, as this would adversely affect the sensitivity of the measurement.

Mini-Switch LB 471

If the bracket cannot be installed on the container, then it has to be mounted on the girder located in the vicinity. Figure 10 shows three alternative proposals for installing the detector (A, B, C).

Chapter 5 Installation

Figure 11:

GM detector

mounted on bracket

Figure 12:

Examples of

installed detectors

View from above

Red marking strips for counter tube position

Bracket

Radiation path

Installation with clamps

Make a suitable bracket for the container.

Using the drawing below, drill 4 holes (d=11 mm) into the

bracket for the clamps.

Install the bracket either directly on the container or on a

sturdy girder.

Install the detector on the bracket using clamps.

Mini-Switch LB 471

Chapter 5 Installation



Radiation window



Collimator



Connection room



Screwed cable gland

Figure 13:

NaI detector

Figure 14:

NaI detector mounted on a

container

Figure 15:

Alternative installations



  

Bracket provided by customer

Radiation path

A B C

5.2.4 Installation of the GM Detector

The lateral opening (radiation window) in the collimator covers the sensitive area of the detector; it has to face the source.

If the bracket cannot be installed on the container, then it has to be mounted on the girder located in the vicinity. Figure 15 shows three alternative proposals for installing the detector (A, B, C).

Mini-Switch LB 471

Chapter 5 Installation

Figure 16:

NaI detector

mounted on bracket

View from above

Radiation path

Radiation path Bracket

Slot is required only when a water cooling is used.

Bracket

Installation with clamps

Make a suitable bracket for the container.

Using the drawing below, drill 4 holes (d=11 mm) into the

bracket for the clamps.

Install the bracket either directly on the container or on a stur-

dy girder.

Install the detector on the bracket using clamps.

Mini-Switch LB 471

Chapter 5 Installation

Figure 17:

Installation proposal

with detector holder

Figure 18:

Bracket with drilled holes

for detector holder

Installation with detector holder (chapter 5.2.2)

Make a suitable bracket for the container.

If the holder is not welded onto the bracket, drill 2 holes

(d=17 mm) for the holder in the bracket, using the drawing below.

Install the bracket either directly on the container or on a stur-

dy girder.

Install the holder with the detector on the bracket.

Mini-Switch LB 471

Chapter 5 Installation

Figure 19:

Installation with

Super-Sens detector

Figure 20:

Super-Sens mounted

on a container

Square hole distance: 198 mm

Diameter: >160 mm

Length of angle iron depending on thickness of insulation

Bracket provided by customer

Radiation path

5.2.5 Installation of Super-Sens

with Axial Irradiation

The axial radiation window, located in the center of the flange, covers the sensitive area of the detector. The radiation window must face the source.

Mini-Switch LB 471

Chapter 5 Installation

Warning!

Risk of damage! Heat conduction above the bracket or heat radiation from the container may destroy the detector. Heat conduction has to be reduced using a heat-resistant sealing between bracket and flange of the Super-Sens detector.

Figure 21:

Super-Sens mounted

on a container

View from above

Rad. path

Radiation path Bracket

Installation

Make a suitable bracket for the container.

Using the drawing below, drill 4 holes (d=18 mm) into the

bracket for the flange.

Install the bracket either directly on the container or on a stur-

dy girder.

Install the detector on the bracket using the flange.

Mini-Switch LB 471

Chapter 5 Installation

Figure 22:

Install Super-Sens

with lateral irradiation on

container

Bracket provided by customer

Radiation path

5.2.6 Installation of Super-Sens

with Radial Irradiation

The radial radiation window, located on the side, covers the sensitive area of the detector. The radiation window must face the source.

Mini-Switch LB 471

Chapter 5 Installation

Installation

Make a suitable bracket for the container.

Using the technical drawings on pages 127 to 130, drill 4 holes

(d=18 mm) into the bracket for the flange.

Install the bracket either directly on the container or on a

sturdy girder.

Install the detector on the bracket.

Mini-Switch LB 471

Chapter 6 Water Cooling

If the detector is installed horizontally, then the bottom connection piece is to be used as water inlet.

Connecting the water cooling device

If the detector is mounted vertically, then the connection box has to face up so that the fittings are located on the top end of the water cooling.

Inlet

Outlet

Inlet

Outlet

bottom

top

Connection box

Chapter 6. Water Cooling

A water cooling device is needed if the ambient temperature may rise above the max. permitted value. The maximum operating temperature for the respective detector is listed in the technical data section on page Chapter 13.

If a water cooling device is installed on the detector, the connection piece has to be aligned such that the water feed pipes can be connected easily. Make sure that the water pipes do not lead past the radiation window. Keep the following in mind to prevent that an air cushion builds up in the water cooling device:

Horizontal installation:

Vertical installation:

This rule applies to all detector types.

Mini-Switch LB 471

Chapter 6 Water Cooling



Water inlet



Water outlet



Connection between

both cooling jackets

Warning!

Risk of damage! The cooling water flow must not be turned off if the maximum ambient temperature of the detector (see technical data in chapter

13.2) will be exceeded even if the facility is not in operation. In case of danger of frost the water cooling has to be emptied. Dirty cooling water may block up the water cooling so that the detector may get overheated and destroyed. Make sure to use clean cooling water!

Super-Sens with water cooling



 

In a Super-Sens with water cooling, the water cooling device is integrated in the case. The water cooling comprises two cooling jackets which have to be connected with each other during installation.

Mini-Switch LB 471

Chapter 6 Water Cooling

6.1 Subsequent Installation of Water

Cooling (Option)

If you are working with the NaI detectors LB 4401, LB 5401 or GM detectors, you may install a water cooling subsequently. See technical drawings on pages 121 and 122.

Preparation

You need clamps with a large diameter (90 mm) in order to fix the detector later at its position again. These clamps have to be ordered separately in addition to the water cooling. If you are using a detector holder instead of the clamps, you only have to remove the plastic ring. See technical drawings on pages 123 and 124.

Depending on the type of detector, a different type of water cooling may be needed. The assembly instructions apply to the following detector types:

 NaI detector with collimator  NaI detector without collimator  GM detector

Mini-Switch LB 471

Chapter 6 Water Cooling



Cooling nozzle



Drilled hole for screws



Screws

(~30mm long)



Collimator



Water cooling



Detector

Figure 23:

Water cooling for

NaI detector

Installing the water cooling

Figure 24:

Fastening screws

for collimator

Figure 25:

NaI detector

with water cooling













6.1.1 Water Cooling for NaI Detector

with Collimator

Collimators only have detectors with 50/50 crystal such as:

 LB 4401-03  LB 5401-03

Pull off collimator from detector. To do this, open the four

screws on the front side.

In order to install the collimator and the water cooling again to the detector, you need four screws which are 5 mm longer than the original screws.

Push the cooling jacket over the detector.

Mini-Switch LB 471

Chapter 6 Water Cooling



Screws



Plastic ring



Detector with water

cooling



Collimator

Figure 26:

Collimator for

NaI detector

Figure 27:

NaI detector with water

cooling and collimator





Positioning the pitch circle





Remove the plastic ring  from the collimator by opening the

screws  on the side of the collimator.

Push the collimator over the water cooling so that the radiation

window is facing the source. Position the collimator and water cooling towards the pitch circle of the detector. Make sure that the position of the cooling nozzle is such that you later have unimpeded access to install the water feed pipes.

Mini-Switch LB 471

To install the collimator and the water cooling on the detector,

you have to use the 5 mm longer screws mentioned above.

Chapter 6 Water Cooling



Screws



Cover plate

Installing the water cooling

Figure 28:

NaI detector

without collimator





6.1.2 Water Cooling for NaI Detector

with Collimator

Open the four frontal screws  of the cover plate . Leave

the cover plate and the lead plate below it in their position.

In order to install the water cooling to the detector, you need four screws which are 5 mm longer than the original screws (not included in delivery).

Push the cooling jacket over the detector.

Position the water cooling on the pitch circle of the detector.

Make sure that the position of the cooling nozzle is such that you later have unimpeded access to install the water feed pipes.

Now fix the collimator with the four screws which are 5 mm

longer than the original screws.

Mini-Switch LB 471

Chapter 6 Water Cooling



Cooling nozzle



Water cooling



Locking screw



Water cooling



GM detector



Locking ring

Figure 29:

Water cooling for

GM detector

Installing the water cooling

Figure 30:

Water cooling with

GM detector

Figure 31:

Water cooling

installed on

GM detector













6.1.3 Water Cooling for GM Detector

Push the cooling jacket over the detector.

Make sure that you position the cooling nozzle such that you later have unimpeded access to install the water feed pipes.

Tighten the locking ring  for the water cooling.

Mini-Switch LB 471

Chapter 6 Water Cooling

Warning!

Risk of damage! The cooling water flow must not be turned off if the maximum ambient temperature of the detector (see technical data in chapter

Figure 32:

Characteristic curve for

cooling water requirement

Required cooling water for NaI point detector

100

150

200

250

100

110

120

130

140

150

160

170

180

Ambient temperature in °C

Water flow rate in l/h

40°C

Cooling water feed temperature

30°C

10°C

20°C

6.2 Amount of Cooling Water Required

The amount of cooling water required may be taken from the graph below.

 The X-axis shows the max. achievable ambient temperature.  The different characteristic curves are valid for the respective

feed temperature of the cooling water.

 The Y-axis shows the min. required water flow.

Mini-Switch LB 471

Chapter 7 Shielding Installation

Caution!

Radioactivity! Installation and start-up of radiometric measuring systems may be carried out only by persons who have been instructed adequately by professional personnel! Work is carried out under the guidance and supervision of the radiological safety officer. It has to be ensured that the lock of the shielding is closed. Damage on the shielding must be avoided. The shielding should be positioned as closely as possible to the container surface. The radiation danger sign has to be installed very close by to the shielding. The controlled area, if there is one, has to be identified and, if necessary, secured. How to calculate the radiation exposure during installation of the shielding is described on page 101. The user has to be familiar with the radiation protection guidelines in Chapter 11.

Note!

Especially for measuring points with Super-Sens detector, the shielding should be installed only after the zero count rate has been determined, since the residual radiation from the shielding (even if the shielding is closed) may distort the measurement of the zero count rate. See also code 32 in the software description.

Chapter 7. Shielding Installation

7.1 General Installation Instructions

Mini-Switch LB 471

Chapter 7 Shielding Installation

Arrangement

Figure 33:

Installation on

a container

Installation sequence

Shielding

Monitoring level

Bracket provided by customer

Source and center of the detector have to be installed on a horizontal line. At the same time, this horizontal line is the monitoring level where the device switches. The shielding is installed at the measuring point by means of brackets.

Install suitable bracket which has to be provided by the cus-

tomer on the respective level. See installation proposal below.

Unpack source with shielding and mount it on the respective

bracket.

If you are working with a shielding with pneumatic shutter, a compressed air connection has to be available. Signals supplied by an optional limit switch have to be connected via an electrical line (see Shielding LB 744X with Pneumatic on page 132).

7.2 Installation Proposal for Shielding

The shielding container comprises a lead-filled sturdy cast iron case. A revolving shutter is installed to close the radiation exit channel. This shutter is operated from the rear side via a lever, which can be locked by means of a padlock in its open or closed position. For installation, the shielding container includes a cast-on flange and in addition a fastening foot with threaded holes. The specifications for the required drilled holes are listed in the Appendix on page 131.

Mini-Switch LB 471

Chapter 7 Shielding Installation

Figure 34:

Installation proposal

for shielding

Figure 35:

Example of

flange installation

Flange installation

Installation on pedestal

LB 7440 LB 7445

LB 7442 LB 7445

LB 7444

120

161

Mini-Switch LB 471

Chapter 7 Shielding Installation

7.3 Pneumatic Shielding Shutter (Option)

A pneumatically operated shutter is available as a special version. When turning on the compressed air, the locking core moves to the “OPEN” position. In case of failure of the compressed air, the shutter is turned by to the “CLOSED” position by a flat spiral spring. A switching contact indicates the shutter position. For technical details and drawings see page 132 in the Appendix.

Mini-Switch LB 471

Chapter 8 Electrical Installation

Danger!

The special aspects of intrinsically safe installation have to be taken into consideration.

In Ex-areas the detector has to be connected with the equipotential busbar of the facility.

In Ex-areas and for measurements that are not intrinsically safe the evaluation unit has to be disconnected from power during the electrical installation.

If the intrinsically safe electric circuit is installed in areas engendered of dust explosion which are classified as area 20 or 21, it has to be ensured that the devices which are connected to these electric circuits fulfill the requirements of category 1D or 2D and have been certified accordingly.

A length of thread1 of 50 mm has to be observed between intrinsically safe connections and connections that are not intrinsically safe.

The maximum cable length between detector and evaluation unit has to be observed. It is dependent on the capacity and inductivity of the cable used and is limited by the max. permissible values stated on the ATEX certificate on page 109. If you are using the cable #32024 supplied by BERTHOLD TECHNOLOGIES, then the max. cable length is 1000m.

The EU type verification documents are shown on page 109.

Warning!

Malfunction due to electromagnetic fields in the line between evaluation unit and detector.

Installation of the line in multi-wire cables is permitted, provided the other parallel running wires are only signal lines, not power lines.

If electromagnetic interference is likely to occur in the line, the cable has to be installed separately in a shielded cable. The screen may be put onto the detector only one-sided.

Strong electromagnetic fields in the line are not permitted. The lines have to be installed such that they do not run parallel to HVpower cable or, for example, frequency converter lines.

The 2-wire connection cable between detector and evaluation unit must not exceed 40Ω2.

Chapter 8. Electrical Installation

Mini-Switch LB 471

The length of thread is the shortest distance between two points that

can be connected by a thread.

Feed and return line

Chapter 8 Electrical Installation

8.1 Connecting Evaluation Unit and Detector

The detector is connected via a 2-wire cable (2 x 1 mm²). In a wall housing one has to observe the permitted cable cross-section of the screwed cable gland. At ambient temperatures >70°C the installed cable has to be protected to ensure that the temperature limits of the cable will not be exceeded. When installing the connection cable, make sure that no water can get inside the connection room via the cable. After connection, the connection room has to be locked again carefully and the cable gland has to be sealed well.

The LB 471 limit switch is available in three different versions:

 In a 19" rack  In a wall housing  In a cassette with terminal block for any 19" rack.

The respective connection diagram is shown on page 137 in the Appendix.

On the following pages we will explain how to connect different detector types separately and in detail.

Mini-Switch LB 471

Chapter 8 Electrical Installation

No.

Designation

2a / 2c

Detector connection depending on the version:

- “intrinsically safe”

- “not intrinsically safe”

12a / 12b / 10c

Relay 2: Alarm relay with change-over contacts SPDT (shutter 12a/c: open in case of alarm and in the idle state break contact: 10c/12c) alternatively configurable as max/min

AC: max. 250V, max. 1A, max 200VA

DC: max. 300V, max. 1A, max. 60W at resistive load

14a / 14c

Relay 3: warning relay (shutter: open in case of alarm and in the idle state)

16a / 16c

Relay 1: collective failure message (shutter: open in case of alarm and in the idle state)

20a / 20c

Digital input 2 Reserve

Enable the digital inputs by shortcircuiting the terminals.

22a / 22c

Digital input 3 for empty calibration If this input is enabled, an empty calibration is carried out automatically followed by a calibration.

30a / 30c

Supply: 18 – 30 V DC or 24V AC Power consumption: approx. 4 VA(AC), 4 W(DC)

32a / 32c

Grounding terminals

8.1.1 Pin Assignment of Terminal Block

The terminal block of the limit switch includes the following connections:

Only in the 7-TE cassette, these contacts are led through directly. In case of the 19" rack and the wall housing, the respectively lead through terminals are used. See connection diagrams in the Appendix on page 137.

Mini-Switch LB 471

Chapter 8 Electrical Installation



Detector cover



Cover screws

Figure 36:

NaI detector cover



  

8.1.2 Installing NaI Detector or Super-Sens

The connection box for the Super-Sens detector is the same as for a detector with NaI detector with 50/50, 40/35, or 25/25 crystal.

Install cable between evaluation unit and detector. For maxi-

mum cable length see the technical data on page 105.

Unscrew three screws at the detector cover.

Take off cover.

Insert line.

Cable bushing (M 16) for cable Ø 8...10 mm. Cable bushing has to face down in order to prevent water from penetrating. For detectors with collimator please keep in mind that the radiation entry window always has to face the source. If necessary, open the collimator at the four frontal screws and adjust the position.

If necessary, place screen separately on terminal 5 ( ). The

screen cable must be insulated to avoid a short-circuit with other terminals.

Connect line to terminals 1 (+) and 2 (-).

Mini-Switch LB 471

Chapter 8 Electrical Installation



Terminal 1 (+)



Terminal 2 (-)



Terminal 5 ( )



Cable bushing M16

Figure 37:

Terminal assignment

NaI detector









Attach cover again and fix it

Connect grounding on the outside of the grounding screw at

the detector.

Place wires on evaluation unit. See connection diagram on

page 137.

8.1.3 Installing the GM Detector

Install cable between evaluation unit and detector. For maxi-

mum cable length see the technical data on page 105.

Unscrew three screws at the detector cover.

Take off cover.

Insert line.

Cable bushing (PG 16) for cable Ø 6 to 8 mm. Cable bushing has to face down in order to prevent water from penetrating.

Mini-Switch LB 471

Chapter 8 Electrical Installation



Screwed cable gland



Install screwed cable

gland on line



Screen



Terminal 2 (-)



Terminal 6 (+)



Cable bushing PG 16

Figure 38:

Terminal assignment

GM detector







  

If necessary, place screen separately on the cable bushing.

Connect line to terminals 6 (+) and 2 (-)

Attach cover again and fix it.

Connect grounding on the outside of the grounding screw at

the detector.

Place wires on evaluation unit. See connection diagram on

page 137.

Mini-Switch LB 471

Chapter 8 Electrical Installation

Relay

Alarm or idle state

Normal

Error

Alarm

Warning

(8)

(9)

16c

16a

(8)

(9)

16c

16a

(3)

(4)

(5)

12c

12a

10c

(3)

(4)

(5)

12c

12a

10c

(6)

(7)

14c

14a

(6)

(7)

14c

14a

8.2 Digital In-/Outputs

8.2.1 Relays

The status of the measurement is indicated by three relays:

Digits in bracket are the connection contacts for the wall housing.

The respective switching state of the relays is also signaled by LED’s on the front panel.

8.2.2 Digital Input

The digital input is used to perform an empty calibration from the control station. The following terminals have to be short-circuited with each other to enable external empty calibration:

 19" rack: „D in –“ with „D in +“  Wall housing: 13 with 14  Cassette: 22a with 22c

The contacts (20a/c) labeled Reserve are without function.

Mini-Switch LB 471

Chapter 8 Electrical Installation

Danger!

Installation work on the electrical equipment may be carried out only in the idle state. The components concerned have to be turned off first and have to be secured against restoring power. The respective VDE and Ex-regulations have to be observed. In Ex-facilities which are not intrinsically safe voltage may be on the detector line only after the line has been connected to the detector and the connection box has been properly closed.

Warning!

Risk of damage! Before establishing the connection, check if the line voltage matches the voltage for which the device has been designed. The supply of the evaluation unit(s) has to be guided via a separate fuse. An easily accessible shut-down has to be foreseen if the power supply unit supplied is not equipped with a power switch.

Note!

Operation and calibration of the evaluation unit is described in the software manual in the second user’s guide.

8.3 Connecting the Evaluation Unit to

Power

 In a 19" rack, mains connection is established via the “LINE”

terminals on the instrument rear panel.

 Wall housing:

The terminal clamps are accommodated in the connection box at the bottom of the case. Unscrew cover.

 Cassette

The terminal clamps are located on the optional terminal block.

Connection diagrams on page 137 in the Appendix.

 The measurement is ready for operation as soon as the:

- lines have been properly connected

- supply voltage has been turned on

- shielding has been opened

Mini-Switch LB 471

Chapter 9 Maintenance

Danger!

Installation work on the electrical equipment may be carried out only in the idle state.

The components concerned have to be turned off first and have to be secured against restoring power.

The respective VDE and Ex-regulations have to be observed.

Malfunction

Cause

Remedy

System does not work or no reading on display

Power supply faulty

Check power supply

Fuse on power supply unit faulty.

Check fuse, replace it, if necessary

Fuse on evaluation unit faulty

Check fuse on evaluation unit, replace it, if necessary

Warning!

Chapter 9. Maintenance

9.1 Malfunctions

9.2 Replacing Fuses

In case of blown fuses you have to investigate the cause first. If you suspect a fault on the board, you have to return if for repair or replace it.

Turn evaluation unit off and disconnect it from mains.

Pull evaluation unit out of rack or cassette.

Check fuses and replace them, if necessary.

Mini-Switch LB 471

Chapter 9 Maintenance

Risk of damage! Use only fuses having the same rating and the same response behavior as the one being replaced.

Figure 39:

Board of

limit switch

evaluation unit

Replacing the EE-Prom

Fuse for supply: T 315mA, 250V

EE-Prom for storing the parameters

9.3 Replacing the Evaluation Unit

When replacing the evaluation unit, we recommend that you take the plug-in EE-Prom from the old device and insert it into the new one (see Figure 39). All parameters and settings will be retained. The EE-Prom has to be protected against destruction by electrostatic charge.

9.4 Repairing the Detector

If you suspect any error in the detector, you may replace the entire detector or individual parts.

 evaluation unit is turned off and disconnected from mains  radiation exit channel on the shielding containing the source is

closed.

Mini-Switch LB 471

Chapter 9 Maintenance

Caution!

Risk of poisoning! If you touch the coupling ring (see Figure 43) made of lead (only with NaI detector 50/50) there is the risk of poisoning. Wear protective gloves or wash your hands after installation.

Parts to be replaced

9.4.1 Dismantling the NaI Detector

The following parts are available as spare parts for the NaI detector and may be replaced.

 Crystal-multiplier combination  Crystal  Multiplier  Detector electronics complete with base  Detector case  Detector cover  Screwed cable gland

Mini-Switch LB 471

Chapter 9 Maintenance



Allen screws size 3



Electronics



Blue base



Multiplier-crystal

combination

Dismantling the detector electronics

Figure 40:

Base screws

NaI detector



Electronics base



Electronics



Crystal-multiplier

combination



Case

Figure 41:

Dismantled NaI detector

Figure 42:

Crystal-multiplier

combination and

electronics



  







Unscrew three screws and take off cover (see also page 74.)

Disconnect cable.

Open screws of clamps and dismantle detector.

Unscrew six screws (Allen screw, size 3).

Carefully pull electronics base  with electronics  and crys-

tal-multiplier combination  out of the case . Make sure that the rubber disc at the bottom of the case does

not fall out, but remains flat at the bottom of the case.

Pull off crystal-multiplier combination  from blue base .

Mini-Switch LB 471

Chapter 9 Maintenance

Warning!

Multiplier may get damaged. During servicing, the multiplier must not be exposed to bright light.



Mu-metal shielding



Coupling ring



Mu-metal shielding



Multiplier



Crystal



Coupling ring

Dismantling the crystalmultiplier combination

Figure 43:

Multiplier-

crystal combination

Figure 44:

Dismantled crystal-

multiplier combination





  



Unscrew coupling ring  from the Mu-metal shielding .

Twist crystal  sideways (do not pull) to detach it from the

multiplier . Crystal or multiplier can now be replaced separately.

Mini-Switch LB 471

Chapter 9 Maintenance



Crystal



Magnetic shielding

(Mu-metal)



Photomultiplier



Optical connection

Crystal is OK if

Crystal has to be replaced if

the crystal appears to be crystal-clear inside, does not have any cracks nor milky spots and has a slightly greenish coloring.

the crystal shows a clear yellowish to brownish coloring.

Multiplier is OK if

Multiplier has to be replaced if

the vapor deposited layer in the multiplier window (photo cathode) has a slight brownish or tinted glass like coloring.

the vapor deposited layer is no longer available or spotted (cathode destroyed e.g. due to overheating, breakage of glass or incidence of light).

Figure 45:

Multiplier-crystal

combination









9.4.2 Checking the Crystal-Multiplier Combination

Often, faulty parts can easily be detected through visual inspection of crystal and multiplier.

If no errors are visible, you can check the function of the crystalmultiplier combination by performing a plateau measurement.

Mini-Switch LB 471

Chapter 9 Maintenance

Warning!

Multiplier may get damaged! During servicing, the multiplier must not be exposed to bright light. Do not bolt together Mu-metal and coupling ring too hard, as this may destroy the multiplier. Tighten parts only until you encounter a slight resistance.



Multiplier



Optical contact area



Drop of silicon oil

Assembling the crystalmultiplier combination

Figure 46:

(Photo) Multiplier







9.4.3 Assembly of Crystal-Multiplier Combination

Before assembling the crystal-multiplier combination, clean the

optical contact area  with a soft cloth to remove remaining silicon oil residues. The same is true for the crystal.

Apply a drop of pure silicon oil  onto the optical contact ar-

ea  of the multiplier.

Attach crystal.

Gently push the crystal with a slightly rubbing motion against the multiplier to distribute the drop of silicon oil and to establish a good optical connection.

Push the Mu metal screen over the multiplier and fix the com-

bination again to the coupling ring with screws.

Mini-Switch LB 471

Chapter 9 Maintenance

Note!

The radiation conditions have to be constant as long as the plateau measurement is running! This means that the level must remain below the limit level during measurement. The radiation channel of the shielding must be open in order to utilize the maximum radiation field for the measurement.

Figure 47:

Typical plateau curve

100

200

300

400

500

600

700

800

900

1000

1100

c p s

Plateau

HIGH VOLTAGE





600V

900V

1200V

1500V

9.4.4 Plateau Measurement

Errors in the crystal-multiplier combination are indicated by a plateau that is either too short or too steep. A plateau measurement is used to check the function of the detector. The result of a plateau measurement is presented in a table or a graph.

A plateau is the flat section in the characteristic curve and is typically approx. 200 V long. The crystal-multiplier combination or the complete detector has to be replaced if:

 the plateau is shorter than 50 V  the count rate changes by more than 5% per 100 V high volt-

age.

The plateau measurement can be started via a software function. See software manual.

Mini-Switch LB 471

Chapter 9 Maintenance



Electronics base



Electronics



Counter tube



Detector case

Dismantling the GM detector

Figure 48:

Detector

connection box

Figure 49:

GM detector

dismantled

  



Termi-

9.4.5 Dismantling the GM Detector

The following parts of the GM detector can be replaced:

 Counter tube  detector electronics

Take off cover on connection box and disconnect cables as de-

scribed on page 75.

Unscrew 6 Allen screws (size 4).

Carefully pull electronic base  with electronics  and coun-

ter tube  out of the detector case .

Now you can do a visual inspection of electronics and counter

tube. Both parts can be replaced separately, if necessary. The counter tube is fixed to the board by two cable ties and a silicon sealing compound.

Mini-Switch LB 471

Chapter 9 Maintenance

Caution!

Radioactivity! Only competent and licensed persons, in compliance with the official regulations, may replace radioactive sources. Coordination with the radiological safety officer is required. All work required has to be prepared such that it can be carried out quickly, so that exposure to the unshielded source is kept to a minimum. Since these persons have to work with an unshielded source for a short time, they have to carry a pocket dosimeter indicating the level of radiation in order to document the actual radiation exposure during work. The user has to be familiar with the radiation protection guidelines in Chapter 11.

9.5 Replacing the Source

A source has to be replaced if the statistical fluctuations reach an unacceptable level in the course of time and compensation by increasing the time constant is not permitted any more, e.g. for control engineering reasons. If a source has to be replaced, the source number of the previously used source has to be stated on the re-order. The source number is stated on the type label of the shielding and on the seal certificate of the source.

Mini-Switch LB 471

Chapter 9 Maintenance

Caution!

Radioactivity!

Do not touch the source with your fingers to avoid a high partial body dose.

Preparation

Point sources are mounted on source holders which are then screwed into the shielding, positioning the source in the center of the shielding. Prerequisite for this work is that the personnel are familiar with the exact shielding construction; therefore, the relevant drawings have to be available. You should have the following tools handy:

 Allan keys in the required sizes: 10, 12 and 13  2 pairs of pliers to take grasp source and source holder.

If sufficient space is available, the source can be replaced directly in the shielding installed on the container. Prepare an auxiliary shielding (shielding container, lead bricks, concrete stones, etc.) at a suitable place and deposit the old and the new source in its transport shielding there for a short period of time.

Mini-Switch LB 471

Chapter 9 Maintenance



Shielding



Lever



Padlock



Safety screw



Knob



Shielding





Locking core





Radiation channel





Point sources





Source holder



Lever





Padlock





Cover plate

Figure 50:

Point source shielding

Figure 51:

Point source shielding -

sectional drawing









Rotate by 90°



  











9.5.1 Replacing the Source

Open padlock  on the shielding.

If necessary, unscrew safety screw  from lever.

Pull off knob  and rotate lever  to the right by 90 degrees

to the center position between “OPEN” and “CLOSED”. The Allen screw head of the source holder is now visible. (With some versions the shutter plate has to be removed to be able to unscrew the source holder.)

Using a socket wrench (size 12), unscrew the source holder 

together with the source.

Mini-Switch LB 471

Chapter 9 Maintenance

Note!

Make sure that no mix-up with other sources occurs.

Grasp the source holder at the rear threaded part and pull it

out. Keep source holder with the source far away from your body and put it down behind the shielding or an auxiliary shielding.

Grasp source holder with a socket wrench and unscrew the

source from the source holder with a second socket wrench (size 10). For this work, you may use the shielding housing as an auxiliary shielding between source and body.

Grasp source with a pair of pliers and place it immediately into

the auxiliary shielding.

If required, clean and grease the thread on the source holder

and on the shielding.

Using the pair of pliers, take the new source out of the

transport shielding and fix it with screw on the source holder together with the snap ring.

Place source holder with source again into the shielding and fix

it with the socket wrench.

Check the proper “OPEN/CLOSED” function.

Place the old source into the transport shielding and close it

carefully.

After replacement of a source, attach the new source number

on the shielding or replace the type label.

Calibrate system new. See software manual.

Mini-Switch LB 471

Chapter 9 Maintenance

Note!

BERTHOLD TECHNOLOGIES phone numbers: Hotline: +49 (0)7081 177-111 Switchboard: +49 (0)7081 177-0 Fax: +49 (0)7081 177-339 E-Mail: Service@BertholdTech.com

Cable bushing

9.6 Customer’s Service

If you wish to get support by our technical customer’s service, you should have the following data available:

 Device type or “LB” number: e.g. LB 471  Error description (symptoms, appearance, operating state be-

fore/after)

 Information on application  Product being measured  Installation situation  Measuring system, e.g.: level, point sources with point detector  Parameter listing  Source number and / or BERTHOLD commission number  Contact person and call-back number

Mini-Switch LB 471

Chapter 9 Maintenance

Note!

Address:

BERTHOLD TECHNOLOGIES GMBH & CO. KG Service Department Calmbacher Str. 22 75323 Bad Wildbad

9.6.1 Sending in the Electronics

If parts or complete devices have to be send in for repair, please include the following information:

 Device type or “LB” number: e.g. LB 471  Information on error appearance  Delivery address  Billing address  Your order number (if required)  Preferred mode of shipment (if necessary)  Customs value (for cross-border shipment)

Mini-Switch LB 471

Chapter 9 Maintenance

Note!

Transport Manager Phone: +49 (0)7081 177 219.

9.6.2 Sending in Source and Shielding

If source and shielding have to be send in for repair, please contact the transport manager of BERTHOLD TECHNOLOGIES:

Information required by the transport manager:

 Name, address, phone number of the radiological safety officer  Number of sources  Source number(s)  Isotope, activity  Date of last wipe test  Condition of source(s) and shielding(s)  Information on the type of shielding in which the source will be

transported (if available)

 Proforma invoice for source and shielding in which the source is

to be shipped back (only for custom’s purposes and only for

cross-border transport).

The shipment is then carried out, as needed, using a forwarding agency that is specially trained for source transports, or via air freight. Details have to be coordinated with our transport manager.

Mini-Switch LB 471

Chapter 10 Servicing the Shielding

Chapter 10. Servicing the Shielding

10.1 Checking Shielding and Source

For safety reasons it has to be possible to shut off the active beam any time. Depending on the operating conditions, the performance test has to be repeated in adequate intervals3, at the latest every six months. In case of malfunction or sluggishness of the rotary shutter the radiological safety officer and the manufacturer have to be notified immediately.

10.1.1 Testing the Locking Mechanism

This test ensures that the locking mechanism functions correctly, the shutter is closed and the source completely shielded if the de-

vice handle of cylinder indicates “Closed”. This is very important to

avoid radiation exposure if for whatever reason (e.g. due to a broken shaft in a point source shielding) “Closed” is indicated although the shutter is still open. The radiation protection agency stipulates that this test be performed in intervals of no more than 6 months. Maybe you will be called upon to present the corresponding documentation on tests carried out in the past and also a time schedule for upcoming tests.

 Notify the process control station that the measuring point is

out of operation during the test.

 Read off current count rate on the evaluation unit and write it

down.

 Move shutter to the position “Closed” and watch if the dis-

played count rate goes back to zero or a very low background level (write down data).

 Repeat this process 5 times and write down the results every

time.

 Make sure that the shutter is freely movable.  Notify the radiological safety officer about the result.  In case of errors or doubt – please contact the service depart-

ment of BERTHOLD TECHNOLOGIES.

 Document test including date, device model and serial number,

test results, name of tester. The regulatory authority may request a copy of the documentation.

Mini-Switch LB 471

In the USA: every six months

Chapter 10 Servicing the Shielding

10.2 Leak Test

Depending on the regulatory authority of the country in which the source is being used, recurrent leak tests, so-called wipe tests, have to be carried out.

10.2.1 Leak Test Documentation

 Inventory listings of the source to be tested with information

on the leak tests carried out in the past.

 Source certificate stating the following information:

Nuclide, activity, procurement date, physical-chemical form Description of encasement and type of sealing Resistance to mechanical and thermal effects or classification of

the source construction type Information on location, application purpose and the customary

maximum mechanical and thermal stress.

Is the source is installed in a device, a drawing has to be enclosed which clearly states the position of the source and all parts serving as protection against external influences. Proposals for the best test method should be provided, e.g. through information on alternative test areas and, if necessary, the required manipulations, i.e. how the test can be carried out without any adverse effect on the operatability of the facility or device. Certificate on acceptance inspection by the manufacturer.

Mini-Switch LB 471

Chapter 10 Servicing the Shielding



Alternative test area



Alternative test area,

if accessible



Point sources



Source holder

Figure 52:

Alternative test areas

on shielding









10.2.2 Performing a Wipe Test

The wipe test is carried out using cotton swabs soaked in solvent. Using the cotton swabs, wipe off the alternative test areas. Any possible contamination is taken up by the cotton swabs. The cotton swabs are then locked air-tight into a repository (plastic bag or plastic container) and checked for contamination.

Rotate lever to horizontal position

The alternative test area is the head or the visible edge of the source holder, respectively. If the cover is also accessible, then you have to wipe there as well.

Mini-Switch LB 471

Chapter 11 Radiation Protection

Chapter 11. Radiation Protection

11.1 Basics and Directives

In order to prevent adverse health effects caused by working with the radioactive substances required for our purposes, limits for the maximum permissible radiation exposure of operating personnel have been agreed upon on an international level. The following information refers to the German Protection Ordinance of August

2001. Appropriate measures in designing the shieldings and arranging the measuring system at the measuring point will ensure that the radiation exposure of the personnel will remain below the maximum permissible value of 1 mSv (100 mrem) per year. To ensure proper handling and the observance of statutory requirements, the company has to appoint a radiological safety officer who is responsible for all radiation protection issues in connection with the measuring system. The radiological safety officer will monitor work with the radiometric measuring system and, if necessary, formalize the safeguards and any special precautions applicable to a given establishment in formal procedural instructions, which in special cases may serve as a basis for radiation protection guidelines. These may stipulate that access to the container shall only be permitted after the active beam is shielded. Radiation protection areas outside the shielding must be – if they are accessible – marked and guarded. These instructions should also include checks of the shutter device of the shielding and provisions for serious operational trouble - such as fire or explosion. Any special event has to be reported to the radiological safety officer immediately. He or she will then investigate any damage and immediately take suitable precautions if he or she detects defects that may adversely affect the operation or safety of the system. The radiological safety officer has to make sure that the provisions of the Radiation Protection Ordinance will be observed. In particular, his or her duties include instructing the staff on the proper handling of radioactive substances. Radioactive sources that are no longer in use or have reached the end of their service life must be returned to the national radioactive waste disposal center or to the manufacturer. Generally, every member of staff should endeavor to minimize any radiation exposure – even within the permissible limits – by careful and responsible action and by observing certain safety standards. The total sum of the radiation dose absorbed by a body is determined by three factors. On the basis of these factors, certain fundamental radiation protection rules can be derived:

Mini-Switch LB 471

Chapter 11 Radiation Protection

100

Distance

Time

Shielding









Distance

This means the distance between the radioactive source and the human body. The radiation intensity (dose rate) decreases – like light – in proportion to the square of the distance: doubling the distance to the source reduces the dose rate to one quarter.

Conclusion:

If work is to be performed in the vicinity of facilities containing radioactive substances, maximum distance has to be maintained. This is especially true for persons who are not directly involved in this work.

Time

The total time a person stays in the vicinity of a radiometric measuring system and the body is exposed to radiation. The effect is cumulative and increases therefore with the duration of the radiation exposure.

Conclusion:

Any work in the vicinity of radiometric measuring systems has to be prepared carefully and organized such that it can be carried out in the shortest time possible. Having the proper tools and aids handy is of particular importance.

Shielding

The material surrounding the source provides the shielding effect. As the shielding effect depends, following an exponential function, on the product of thickness multiplied by the density, it follows that material with a high specific weight is used for shielding purposes. The shielding supplier usually calculates suitable dimensions.

Conclusion:

Before mounting or dismounting the shielding, make sure that the radiation exit channel is locked in the closed position.

You may not remove the source from the shielding!

Mini-Switch LB 471

BERTHOLD TECHNOLOGIES LB4710-050, LB4710-060, LB4710-160, LB4710-080, LB4710-090 User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual

Chapter 1. General Information

1.1 Use and Function

1.2 Target Group

1.3 Radiation Protection Courses

1.4 Definitions

1.5 Safekeeping of the User’s Guide

Chapter 2. Safety

2.1 Safety Concept

2.2 Symbols and Pictograms

2.3 Radiological Safety Officer

2.4 Duty of Notification

2.5 Radiation Protection Areas

2.5.1 Exclusion Areas

2.5.2 Controlled Areas

2.5.3 Monitoring Areas

2.6 Safety Installations

2.6.1 Source Shieldings

2.7 General Safety Instructions

2.8 Emergency Instructions

2.8.1 Theft Protection

Chapter 3. Functional Safety

3.1 Use and Function

3.2 Safety Function

3.3 Safety Requirement

3.4 Project Planning

3.5 Getting Started

Reset

3.7 Recurrent Performance Test

3.8 Safety-Technical Data

Single channel architecture

Two-channel architecture

Chapter 4. Instrument Description

4.1 Function

4.2 Mini Switch LB 471 Versions

4.2.1 Type Code

4.3 Detectors

4.3.1 GM Detector

4.3.2 NaI Detector

4.3.3 Super-Sens Detector

Chapter 5. Installation

5.1 Transport to the Installation Site

5.1.1 Transporting Detector and Evaluation Unit

5.1.2 Transport Shielding with Source

5.1.3 Temporary Storage of Sources

5.1.4 Installation Site

5.1.5 Unpacking and Cleaning System Parts

5.2 Installing the Detector

5.2.3 Installation of the GM Detector

Installation with clamps

5.2.4 Installation of the GM Detector

Installation with clamps

Installation with detector holder (chapter 5.2.2)

Installation

Installation

Chapter 6. Water Cooling

6.1.3 Water Cooling for GM Detector

6.2 Amount of Cooling Water Required

Chapter 7. Shielding Installation

7.1 General Installation Instructions

7.2 Installation Proposal for Shielding

7.3 Pneumatic Shielding Shutter (Option)

Chapter 8. Electrical Installation

8.1 Connecting Evaluation Unit and Detector

8.1.1 Pin Assignment of Terminal Block

8.1.2 Installing NaI Detector or Super-Sens

8.1.3 Installing the GM Detector

8.2 Digital In-/Outputs

8.2.1 Relays

8.2.2 Digital Input

Chapter 9. Maintenance

9.1 Malfunctions

9.2 Replacing Fuses

9.3 Replacing the Evaluation Unit

9.4 Repairing the Detector

9.4.1 Dismantling the NaI Detector

9.4.2 Checking the Crystal-Multiplier Combination