BRUEL & KJAER 2145 Instruction Manual

Brüel & Kjær
7/6-'89
BK
Technical
Documentation
English BB0877–14
Order Tracking Analyzer
Type 2145
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Vol. 1: Operation

March 2006
Brüel & Kjær BB0877–14
Order Tracking Analyzer
Type 2145
From software version 1.20
Revision

0 – 2 Brüel & KjærOrder Tracking Analyzer Type 2145
User Manual Vol.1
Safety Considerations
This apparatus has been designed and tested in accordance with
IEC Publication 348, Safety Requirements for Electronic Measuring
Apparatus (see specifications), and has been supplied in safe condi-
tion. This User Manual contains information and warnings which
must be followed to ensure safe operation and to retain the appara-
tus in safe condition. Special note should be made of the following:
Powering the Apparatus
Before each use of the apparatus verify that it is set to match the
available mains supply voltage and that the correct fuse is inserted.
Safety Symbols
The apparatus will be marked with this symbol when it is
important to refer to the associated warning statements given in
this User Manual.
Warnings
●Switch off all power to equipment before connecting or disconnecting
their digital interface. Failure to do so could damage the equipment.
●Whenever it is likely that the correct function or operating safety of
the apparatus has been impaired, it must be made inoperative and be
secured against unintended operation.
●Any adjustment maintenance and repair of the open apparatus under
voltage must be avoided as far as possible and, if unavoidable, must
be made only by trained service personnel.
Chassis
Terminal Safety Earth Terminal Hazardous Voltage
Trademarks
IBM is the international trade mark for International Business Ma-
chines Corp.
Copyright © 1993 – 1995, Brüel&Kjær A/S
All rights reserved. No part of this publication may be reproduced
or distributed in any form, or by any means, without prior consent
in writing from Brüel & Kjær A/S, Nærum, Denmark.

BB0877–14 0 – 3 Order Tracking Analyzer Type 2145
User Manual Vol.1
Contents
1. Introduction ............................................................................ 1–1
1.1 About the Type 2145...................................................1 – 2
1.2 About the Type 7668 Software ...................................1 – 2
1.3 About this User Guide ................................................1 – 3
2. Installation and Maintenance ........................................ 2–1
2.1 Power Supply ..............................................................2 – 2
2.2 Grounding Considerations..........................................2 – 6
2.3 Cleaning the Disk Drive .............................................2 – 8
2.4 Installing the Software Key .......................................2 – 9
3. Controls and Connections ................................................ 3–1
3.1 Front Panel..................................................................3 – 2
3.2 Rear Panel ...................................................................3 – 5
4. Getting Started ..................................................................... 4–1
4.1 Switching On...............................................................4 – 2
4.2 General Measurement Procedure ..............................4 – 4
4.3 The Menu and Help Page System..............................4 – 5
4.4 Changing Parameters in a Set-up............................4 – 10
5. Main Menu – Page 1 ........................................................... 5–1
5.1 Introduction.................................................................5 – 3
5.2 Analysis Set-up ...........................................................5 – 4
5.3 Input ............................................................................5 – 8
5.4 Calibration ..................................................................5 – 9
5.5 Tacho Input and Tacho Parameters ........................5 – 19

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5.6 Setting up Tacho Parameters ..................................5 – 23
5.7 Averaging .................................................................. 5 – 33
5.8 Interval Averaging.................................................... 5 – 35
6. Main Menu – Page 2 ........................................................... 6–1
6.1 Introduction ................................................................ 6 – 3
6.2 Display Modes.............................................................6 – 4
6.3 Text.............................................................................. 6 – 8
6.4 Hold ........................................................................... 6 – 12
6.5 Trigger Multimode.................................................... 6 – 15
6.6 Spectrum Weighting.................................................6 – 32
6.7 Memory......................................................................6 – 37
6.8 I/O Interface.............................................................. 6 – 43
7. Main Menu – Page 3 ........................................................... 7–1
7.1 Introduction ................................................................ 7 – 2
7.2 Preselected Set-up ...................................................... 7 – 2
7.3 Autosequence ..............................................................7 – 4
7.4 Real-time Clock......................................................... 7 – 13
7.5 Back Lighting............................................................7 – 17
7.6 Applications...............................................................7 – 19
8. Analysis Functions .............................................................. 8–1
8.1 Introduction ................................................................ 8 – 3
8.2 Autospectrum Analysis .............................................. 8 – 5
8.3 Order Analysis ............................................................8 – 6
8.4 Broadband Channels ................................................ 8 – 10
8.5 Choosing an Analogue Input Filter ......................... 8 – 11
8.6 Tacho Parameters.....................................................8 – 12
8.7 DC Channels .............................................................8 – 17
8.8 Digital Channel.........................................................8 – 17
8.9 Overload Indicators ..................................................8 – 18
8.10 Summary of Analysis Functions..............................8 – 20

BB0877–14 0 – 5 Order Tracking Analyzer Type 2145
User Manual Vol.1
9. Data Acquisition ................................................................... 9–1
9.1 Introduction.................................................................9 – 2
9.2 Making a Single Measurement ..................................9 – 4
9.3 Trigger Multimode Uses.............................................9 – 5
10. Measurement Mode ........................................................... 10–1
10.1 Measurement Mode Display.....................................10 – 2
10.2 Measurement Mode Pages......................................10 – 14
10.3 Display Modes .........................................................10 – 18
11. Appendix ................................................................................ 11–1
11.1 Personal Computer (PC) Utilities ............................ 11– 2
11.2 Using TEXT7668.EXE .............................................. 11– 2
11.3 Using CONV7668.EXE ............................................. 11– 5
11.4 Remote Control ZH 0611........................................... 11– 8
12. Error Messages ................................................................... 12–1
12.1 Error Messages ......................................................... 12–2
12.2 Provoked Errors and Other Messages ..................... 12–5
13. Specifications ....................................................................... 13–1
13.1 Specifications 2145 ................................................... 13–2
13.2 Filter Characteristics................................................ 13–8
14. Service and Repair ............................................................. 14–1
Index

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User Manual Vol.1

BB0877–14 1 – 1 Order Tracking Analyzer Type 2145
User Manual Vol.1
Chapter 1
Introduction
1.1 About the Type 2145........................................................... 1 – 2
1.2 About the Type 7668 Software....................................... 1 – 2
1.3 About this User Guide........................................................ 1 – 3

Chapter 1 – Introduction
About the Type 2145
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User Manual Vol.1
1.1 About the Type 2145
The Analyzer
The Order Tracking Analyzer Type 2145 is a portable, digital-
filter, frequency analyzer which can also perform order analyses
for acoustics and vibration measurements. Its light weight and
water-repellent cabinet make it especially well-suited for use in
the field. Yet its measuring capabilities easily match those of
laboratory instruments. The analyzer features real-time opera-
tion across its working frequency ranges which are doubled for
single channel operation. It has two versatile tacho trigger inputs
which give the 2145 a tremendous advantage over conventional
analyzers when it comes to analysing motor vehicle sounds and
vibrations. Its is capable of providing, in real-time, 20-order
analysis simultaneously with spectral data in 1/1-, 1
/3 - or 1/12
octave bands.
Menus and Help
The analyzer is operated by means of user-interactive menus.
These enable you to become quickly familiar with the use of the
analyzer. Access to a system of on-screen help pages provides
you with information about the use of the menus at any time
and in any place.
Data Storage
A large internal non-volatile memory together with back-up disk
storage facilities makes the analyzer a powerful data-gathering
device. The IEEE–488 and RS–232 interfaces allow data-process-
ing and external control.
1.2 About the Type 7668 Software
The Type 7668 is the software for the Order Tracking Analyzer
Type 2145. It comes on a single 31/2″disk and is loaded using
the analyzer’s built-in disk drive. A software key must be in-
stalled in the analyzer to allow the program to be run. The
analyzer is already fitted with this key on delivery. It is also

Chapter 1 – Introduction
About this User Guide
BB0877–14 1 – 3 Order Tracking Analyzer Type 2145
User Manual Vol.1
fitted with a key to run the Two Channel FFT software Type
7651.
1.3 About this User Guide
Purpose of Manual
This manual introduces you to the operating principles of the
Type 2145 and gives you an overview of the analyzer’s possibil-
ities. Examples of measurement procedures and data processing
are also given. You will find that the analyzer is very easy to
use once you have become familiar with its working principles.
Summary of Contents
Chapter 2 contains information about electrical considerations
and maintenance of the analyzer. It also contains information
on how to install the software key if this should be necessary.
Each analyzer is delivered with software keys already installed.
Read this if you have to install any new keys in connection with
upgrading your analyzer.
Chapter 3 describes the keys on the front panel and the connec-
tions on the rear panel.
Chapter 4 describes how to load the software, general measure-
ment procedure, set-up and measurement modes, the items on
the main and sub-menus and how to use them efficiently and
how to change operating and numerical parameters.
Chapter 5 deals with page 1 of the MAIN MENU which you will
use when configuring the analyzer to interpret and gauge all
incoming signals in connection with your measurements.
Chapter 6 deals with page 2 of the MAIN MENU which you will
use for setting up your specific requirements for processing meas-
ured and analysed data.
Chapter 7 deals with page 3 of the MAIN MENU which you will
use for pre-selecting set-ups, executing automatic sequences, set-
ting the clock and wake-up times, choosing continuous or eco-

Chapter 1 – Introduction
About this User Guide
1 – 4 Brüel & KjærOrder Tracking Analyzer Type 2145
User Manual Vol.1
nomic back lighting for the screen and accessing extended
analyzer applications.
Chapter 8 gives you an overall view of the various data process-
ing functions available for making measurements.
Chapter 9 describes the structure of data files and the four data
acquisition modes.
Chapter 10 describes the measurement mode and how to inter-
pret the various annotations and header fields.
Chapter 11 tells you how to use the two Personal Computer
utilities for (a) creating labelling text for analyzer files and au-
tosequences and (b) preparing set-up and data files for use with
spread sheets.
Chapter 12 explains the analyzer’s error messages.
Chapter 13 contains the technical specifications and filter char-
acteristics, and Chapter 14 is about service and repair.
Interface
Use of the interfaces (serial and parallel) is described in Vol. 2:
Interface along with information on data formats used by the
analyzer.

BB0877–14 2 – 1 Order Tracking Analyzer Type 2145
User Manual Vol.1
Chapter 2
Installation and Maintenance
2.1 Power Supply.......................................................................... 2 – 2
Battery Installation........................................................... 2 – 2
Mains Supply..................................................................... 2 – 3
Recharging the Batteries .................................................. 2 – 4
Use of a Car Battery for External DC Supply ................. 2 – 5
2.2 Grounding Considerations ............................................... 2 – 6
2.3 Cleaning the Disk Drive.................................................... 2 – 8
2.4 Installing the Software Key............................................. 2 – 9

Chapter 2 – Installation and Maintenance
Power Supply
2 – 2 Brüel & KjærOrder Tracking Analyzer Type 2145
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2.1 Power Supply
The analyzer can be powered using internal batteries, an AC
mains supply (via the ZG0342), or a car battery as an external
DC supply.
2.1.1 Battery Installation
Battery Types
Suitable batteries for the analyzer are 1.25V rechargeable NiCd
batteries, type R20 (“D” size). These have Brüel & Kjær order
numbers QB0008. Six QB0008s are supplied with the analyzer.
Lifetime
At 25°C and from full charge, the batteries provided will power
the analyzer (with back lighting off) continuously for more than
three hours. The operating time is reduced if the disk drive is
used intensively or the temperature decreases.
Inserting Batteries
To insert batteries:
1. Remove the Battery Box ZG0146 by turning the release
screw.
2. Remove the cover by turning the four corner screws.
3. Insert six batteries in the directions indicated inside the box.
4. Replace the cover and insert the battery box into the ana-
lyzer.
5. Secure the battery box by turning the release screw.
6. Label the battery box with the type of batteries contained.

Chapter 2 – Installation and Maintenance
Power Supply
BB0877–14 2 – 3 Order Tracking Analyzer Type 2145
User Manual Vol.1
Caution!
It is possible for batteries to explode or leak if they are handled
incorrectly, so:
●Never attempt to recharge non-rechargeable batteries.
●Never attempt to recharge batteries fitted the wrong way
round.
●Never mix different makes or types of battery.
●Never mix charged and discharged batteries.
●Always label the outside of the battery box with the type of
batteries contained.
●Always remove the battery box before storage or shipment.
2.1.2 Mains Supply
WARNING: NEVER apply an external drive voltage to the an-
alyzer when there are non-rechargeable batteries in it.
To power the analyzer from the mains supply, Power Supply
ZG 0342 (included as accessory) can be connected to the Exter-
nal Power 7-pin DIN plug on the rear panel via Cable AQ 0035.
Fig.2.1 Arrangement for powering or recharging
931012e
Mains
Battery Box
ZG 0146
Power Supply
ZG 0342
Cable AQ 0035
Type
2145
!

Chapter 2 – Installation and Maintenance
Power Supply
2 – 4 Brüel & KjærOrder Tracking Analyzer Type 2145
User Manual Vol.1
This arrangement is shown in Fig.2.1. Alternatively, ZG 0342
can be inserted in place of the battery box.
2.1.3 Recharging the Batteries
Recharging
Power Supply ZG 0342 can be used to recharge the analyzer’s
NiCd batteries when the analyzer is switched off, for example
overnight. The time taken to fully recharge the batteries is ap-
proximately 14 hours. The batteries can be recharged about 1000
times, provided they are not charged for too long (i.e. not more
than 16 hours). The arrangement for this is shown in Fig.2.1.
Simultaneous Powering and Recharging
For simultaneous powering and recharging, use the arrangement
shown in Fig.2.2.
Note on Rechargeable Batteries
The lifetime of the batteries can be reduced if a charging current
is applied for too long a time, especially if the ambient temper-
ature is outside the range of 10 – 40°C. Likewise, NiCd batteries
may exhibit a “memory effect” if used incorrectly. This effect
leads to a decreased operating time, but can be avoided by letting
Fig.2.2 Arrangement for simultaneous powering and recharging
931011e
Type
2145
Charging Adaptor AQ 0157
Battery Box
ZG 0146
Mains
Power Supply
ZG 0342

Chapter 2 – Installation and Maintenance
Power Supply
BB0877–14 2 – 5 Order Tracking Analyzer Type 2145
User Manual Vol.1
the analyzer run to cut-off every time before recharging the
batteries (it is a good idea to have an extra set of charged
batteries ready). Your measurements are saved when the ana-
lyzer cuts off.
Removing the “Memory Effect”
If the operating time becomes considerably less than three hours,
the “memory effect” problem can usually be overcome by deep
discharging and recharging the batteries:
1. Discharge the batteries, for example by using them to power
a flashlight until they are completely run down.
2. Charge the batteries for 20 to 24 hours.
2.1.4 Use of a Car Battery for External DC Supply
Source
If a car battery is used as the external DC supply, and this is
installed in a car, power should be taken at a point after the
car’s fuseboard, or, if the car is equipped with an electric lighter
socket, power can be taken from here using the cable (AO0399)
provided.
Connection
The plug should be mounted on a cable with a 7-pin DIN plug
at the other end. For pin connections, see section 3.2.
Short-circuit Protection
The power supply in the analyzer is isolated from its chassis
and therefore cannot short-circuit the car battery if the analyz-
er’s chassis (or the housing of a microphone) touches the chassis
or bodywork of the car. However, if other instruments are used
with the analyzer, ensure that they are also properly isolated,
otherwise they can short-circuit the car battery.

Chapter 2 – Installation and Maintenance
Grounding Considerations
2 – 6 Brüel & KjærOrder Tracking Analyzer Type 2145
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2.2 Grounding Considerations
WARNING: Care must be taken to limit the Signal Ground
current in order to prevent electrical hazards. Maximum is
50mA.
WARNING: The analyzer is designed to be operated with its
analogue ground and chassis ground at zero potential. Voltage
between these two may be hazardous and must therefore be kept
within the specified safety limits (see Specifications, Chapter 13).
Ground Loops
Indiscriminate grounding of instruments in a measurement sys-
tem can introduce ground-loop interference from magnetic fields.
Ground loops are created where multiple ground paths exist
between two or more points in the measurement system, for
instance where two instruments are interconnected by two sep-
arate signal lines. Circulating currents in these ground loops
generate noise voltages which can lead to less accurate meas-
urements. In extreme cases, the interference generated can also
disrupt the digital communications in a bus-based system.
Grounding the Analyzer
The analyzer terminology operates with three different ground
symbols: signal ground, analogue ground and chassis ground
(rear panel). When the grounding switch on the rear panel is in
“Chassis” position, analogue ground is connected to the chassis
(see Fig.2.3). In “Floating” position, analogue ground is discon-
nected to help break possible ground loops.
Procedure
If the analyzer is part of a measurement system consisting of
several instruments, use the following procedure to ensure that
ground loops are eliminated without affecting the operating safe-
ty of the system.
1. Switch all instruments “Off” before making any changes to
ground connections.
!
!

Chapter 2 – Installation and Maintenance
Grounding Considerations
BB0877–14 2 – 7 Order Tracking Analyzer Type 2145
User Manual Vol.1
2. Connect together the Signal Ground lines of all the instru-
ments in the system – this is done automatically through
the screens of signal input/output connections. Make sure
that the Signal Ground switch is “On” on any instruments
equipped with such a switch.
3. If there is more than one signal cable connecting any two
instruments together, break the signal ground connection in
all but one of the interconnecting cables, either by switching
Signal Ground “Off” or by disconnecting the signal ground
lines in the cables. If this is not possible, use short cables
and bunch the cables together to keep the area enclosed by
cable loops as small as possible.
4. On all instruments which have a ground connection in their
mains supply connector, connect the chassis to mains
Fig.2.3 Simplified circuit diagram showing the grounding principle of
the analyzer (one input channel shown)
913318e
+
–
An. Gnd.
Analogue Circuits
Input
Dig. Gnd.
Digital Circuits
Chassis Gnd.
Chassis/Floating
12V
Chassis
Sig. GND.

Chapter 2 – Installation and Maintenance
Cleaning the Disk Drive
2 – 8 Brüel & KjærOrder Tracking Analyzer Type 2145
User Manual Vol.1
ground. Disconnect the signal ground from the chassis on
all but one of these instruments.
5. In IEEE/IEC bus-based systems, disconnect the signal
ground from the chassis on all but one of the instruments
connected to the bus. Leave the signal ground connected to
the chassis on an instrument with a mains ground connec-
tion, if any are included in the bus system. The bus cables
provide a continuous chassis ground connection between the
instruments.
6. Ensure that metal instrument cabinets do not touch each
other, particularly if the chassis are connected to the signal
ground. In rack-mounted systems, use isolating flanges to
prevent ground loops being formed through the rack itself.
7. If transducers with metal housings are used, isolate the
housings from grounded surfaces.
2.3 Cleaning the Disk Drive
It is advisable to clean the heads of the analyzer’s disk-drive at
regular intervals – once a month is recommended – to avoid
errors when writing to or reading from the disk. For cleaning,
a 31/2″Head Cleaning Diskette Kit is available (Brüel & Kjær
part QA 0168). To clean the disk drive:
1. Prepare the cleaning disk according to the instructions in-
cluded in the kit.
2. Insert the disk in the disk drive.
3. Press “F6” (Memory) on page 2 of the MAIN MENU.
4. Set the Select Memory field to Disk using “F1”.
5. Press “F7” (File List).
6. Press “F8” (Page 1) to return page 1 (step 4).