SIST EN 13848-2:2021

SLOVENSKI STANDARD
01-januar-2021
Nadomešča:
SIST EN 13848-2:2006
Železniške naprave - Zgornji ustroj proge - Kakovost tirne geometrije - 2. del:
Merilni sistemi - Merilna vozila
Railway applications - Track - Track geometry quality - Part 2: Measuring systems -
Track recording vehicles
Bahnanwendungen - Oberbau - Geometrische Gleislagegüte - Teil 2: Messsysteme -
Gleismessfahrzeuge
Applications ferroviaires - Voie - Qualité géométrique de la voie - Partie 2 : Systèmes de
mesure - Véhicules d'enregistrement de la voie
Ta slovenski standard je istoveten z: EN 13848-2:2020
ICS:
45.080 Tračnice in železniški deli Rails and railway
components
93.100 Gradnja železnic Construction of railways
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 13848-2
EUROPEAN STANDARD
NORME EUROPÉENNE
November 2020
EUROPÄISCHE NORM
ICS 93.100 Supersedes EN 13848-2:2006
English Version
Railway applications - Track - Track geometry quality -
Part 2: Measuring systems - Track recording vehicles
Applications ferroviaires - Voie - Qualité géométrique Bahnanwendungen - Oberbau - Geometrische
de la voie - Partie 2 : Systèmes de mesure - Véhicules Gleislagegüte - Teil 2: Messsysteme -
d'enregistrement de la voie Gleismessfahrzeuge
This European Standard was approved by CEN on 5 July 2020.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 13848-2:2020 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Symbols and abbreviations . 8
5 Track geometry recording system . 8
5.1 General description . 8
5.2 Environmental conditions . 9
5.3 Track features input . 10
5.4 Localization device . 11
5.5 Measuring devices . 11
5.6 Resolution . 12
5.7 Signal processing . 12
5.8 Data processing and analysis . 12
5.9 Data presentation and storage . 13
6 Testing of track geometry recording system . 14
6.1 Introduction . 14
6.2 Calibration . 14
6.3 Validation . 14
Annex A (informative) Frequency analysis . 26
A.1 General description . 26
A.2 Practical calculation . 27
A.3 Applications within this standard . 28
Annex B (informative) Principles of measurement . 31
B.1 General description . 31
B.2 Longitudinal level and alignment . 31
B.3 Track gauge . 31
B.4 Cant . 32
B.5 Twist . 32
Annex C (normative) Description of field tests: values to be respected . 33
C.1 General . 33
C.2 Repeatability . 33
C.3 Reproducibility . 35
C.4 Cross check . 36
Annex D (informative) Track geometry measurement uncertainty . 38
D.1 General . 38
D.2 Evaluating uncertainty for track geometry measurement systems . 39
D.3 Measurement uncertainty: limit values . 41
Annex E (informative) Cross checks in the space domain . 43
Bibliography . 44

European foreword
This document (EN 13848-2:2020) has been prepared by Technical Committee CEN/TC 256 “Railway
applications”, the secretariat of which is held by DIN.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by May 2021, and conflicting national standards shall be
withdrawn at the latest by May 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 13848-2:2006.
This European Standard is one of the series EN 13848 “Railway applications — Track — Track geometry
quality” as listed below:
— Part 1: Characterization of track geometry;
— Part 2: Measuring systems — Track recording vehicles;
— Part 3: Measuring systems — Track construction and maintenance machines;
— Part 4: Measuring systems — Manual and lightweight devices;
— Part 5: Geometric quality levels — Plain line, switches and crossings;
— Part 6: Characterization of track geometry quality.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the
United Kingdom.
1 Scope
This document specifies the minimum requirements for track geometry measuring principles and track
geometry measuring systems in order to produce comparable results when measuring the same track.
It applies to all measuring systems, attended or unattended, fitted on any vehicle, except those systems
defined in EN 13848-3 and EN 13848-4. Only systems put into service after the standard comes into
force are concerned.
This document does not define the requirements for vehicle acceptance.
This document does not apply to measuring systems dedicated to Urban Rail Systems.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 13848-1, Railway applications - Track - Track geometry quality - Part 1: Characterization of track
geometry
EN 13848-6, Railway applications - Track - Track geometry quality - Part 6: Characterisation of track
geometry quality
JCGM 200:2012, International vocabulary of metrology – Basic and general concepts and associated terms
(VIM)
3 Terms and definitions
For the purpose of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
track geometry recording vehicle
self-propelled or hauled vehicle with fixed, dedicated, measuring equipment and systems, used for the
measurement, assessment and recording of track geometry parameters under loaded conditions, which
measures and produces consistent results to the requirements of EN 13848-1
Note 1 to entry: The measuring system can be attended or not. The track geometry recording vehicle belongs to
the infrastructure inspection vehicles as defined in TSI Loc&Pas 1302/2014/EU.
3.2
sensor
device which detects, measures and translates characteristics of track geometry into quantities that can
be used for further data processing
3.3
repeatability
degree of agreement between the values of successive measurements of the same parameter made
under the same conditions, within a short period of time, where the individual measurements are
carried out on the same section of track using the same measurement and interpretation methods,
subject to the following controls:
— similar speed;
— same measuring direction;
— same vehicle orientation;
— similar environmental conditions
3.4
reproducibility
degree of agreement between the values of successive measurements of the same parameter made
under varying conditions, within a short period of time, where the individual measurements are carried
out on the same section of track using the same measurement and interpretation methods, subject to
one or more of the following:
— variation of speed;
— different measuring directions;
— different vehicle orientations;
— different environmental conditions
3.5
comparability
degree of agreement of different track recording vehicles achieved under the same conditions
3.6
validation
set of tests for determining if a track recording vehicle complies with the requirements of this standard
3.7
calibration
set of procedures for adjusting the measuring devices of track measuring systems in order to meet the
requirements of this standard as defined in JCGM 200:2012
3.8
event
record of a track or line-side feature that can be either technical, physical or natural
3.9
localization
information required to locate events and the measured track geometry
3.10
reference track
track with known characteristics to allow adequate testing of the track geometry measuring and
recording system
3.11
unattended geometry measuring system (UGMS)
track geometry measuring system fitted on a vehicle, without any human interaction during the
measurements
3.12
adjustment of a measuring system
set of operations carried out on a measuring system so that it provides prescribed indications
corresponding to given values of a quantity to be measured
[SOURCE: VIM - International vocabulary of metrology JCGM 200:2012]
3.13
cross check
method for comparing signals of a single run for linked parameters obtained from different inputs (e.g.
devices or signal processing)
3.14
vehicle orientation
physical positioning of a vehicle, with regards to which end of the vehicle is leading during
measurement
Note 1 to entry: There are two possible vehicle orientations as shown in Figure 1.

Figure 1 — Possible vehicle orientations
3.15
measuring direction
course between two points on a track, independent of the orientation of the track recording vehicle
Note 1 to entry: Between two given points A and B, there are two opposite directions: A to B and B to A.
4 Symbols and abbreviations
For the purpose of this document, the following symbols and abbreviations apply.
Table 1 — Symbols and abbreviations
Symbol Designation Unit
D1 Wavelength range 3 m < λ ≤ 25 m m
D2 Wavelength range 25 m < λ ≤ 70 m m
Wavelength range 70 m < λ ≤ 150 m for longitudinal level
D3 m
Wavelength range 70 m < λ ≤ 200 m for alignment
λ Wavelength m
Vmax Maximum possible measuring speed of a recording system km/h
Vmin Minimum possible measuring speed of a recording system km/h
5 Track geometry recording system
5.1 General description
For the purpose of this document, the track geometry recording system is divided into several units as
represented in Figure 2 below:

Figure 2 — Track geometry recording system
When measuring the same track, track geometry recording systems shall produce results that are
consistent and comparable, irrespective of the measuring speed and direction of travel. The measuring
results can be used for track quality monitoring, maintenance planning and can contribute to the
process of safety assurance as related to track geometry.
The track geometry recording system represents the totality of the equipment required to:
— measure track geometry parameters;
— take measurement or information to allow the position to be determined during measuring
operations;
— associate these two measurements in order to locate precisely on the track the values exceeding a
prescribed threshold or other elements characterizing the track;
— record these parameters on computer readable media;
— calculate, based on the direct measured parameters, other parameters of the track geometry (e.g.
twist, curvature);
— process the measured data, in order to analyse the track geometry parameters;
— present and store the results.
The output of the track geometry recording system shall meet the individual parameter requirements of
EN 13848-1. All the data necessary to determine the parameters specified in EN 13848-1 shall be taken
and stored during the run. The determined parameters should be graphically displayed and analysed in
strict relation to the corresponding distance location.
The track geometry recording system shall be monitored and shall allow measurements of track
geometry as specified in EN 13848-1 under loaded conditions of the track.
The computer system shall be of a kind and type suitable for railway vehicle bound applications.
To prevent the interruption of the track geometry measurement and the loss of recorded data in case
the measuring hardware power supply fails, an adequate uninterruptible power supply should be
provided.
5.2 Environmental conditions
5.2.1 Introduction
All the measuring devices and hardware components fitted on a track-recording vehicle shall produce
reliable results under the environmental conditions specified below.
5.2.2 Climatic conditions
The effects of climatic conditions on components outside and inside the track-recording vehicle shall be
considered. These shall include:
— Outside components
— ambient temperature;
— condensation, particularly with sudden variation of temperature at the entrance or at the exit
of a tunnel;
— possibility of extreme weather conditions (heavy rain, snow, direct sunlight, …);
— ambient relative humidity.
— Inside components
— ambient temperature for operating and storage conditions;
— ambient relative humidity.
5.2.3 Operating conditions
The effects of operating conditions shall be considered. These shall include:
— ballast or iron fragments impacts;
— grease on the rail;
— reflection condition of the rail;
— characteristic light conditions;
— dust, water and snow in connection with aerodynamic conditions;
— safety requirements e.g. laser beam;
— vibrations and shocks;
— electromagnetic environment;
— compatibility with signalling and communication systems.
5.3 Track features input
The track features input supports the data analysis (see 5.8) and shall include at least:
— set of limit values of track geometry parameters as defined in EN 13848-5;
— line speed.
Other inputs can be beneficial as, for example:
— geo-spatial positioning;
— line side features such as switches, level crossings, bridges, tunnels;
— track components and track alignment design parameters.
All this data should be able to be entered by manual or automatic means.
5.4 Localization device
The reference point for the data localization system may be the kilometre post or other fixed points.
The localization device gives the track recording vehicle’s position along the track and shall fulfil the
following functions:
— synchronizes the position with the reference point by one of the various possible methods, using
for example the satellite based positioning system, active or passive beacons, track layout or other
singular points;
— measures the distance covered by the track recording vehicle, compensated for direction “reverse”,
and is generally based on a synchronization signal, which could be given by a wheel-mounted
encoder or any other equivalent method;
— corrects manually or automatically the inaccuracies caused by:
— wear, sliding, conicity of the track recording vehicle wheels;
— non-homogeneous reference post distances (e.g. mileposts that are greater or less than one
mile apart);
— uncertainty of the distance run transducer.
5.5 Measuring devices
5.5.1 General
Track geometry measuring system relies on sensors, signal transmission and signal processing
following various measuring principles as described in Annex B.
The speed range shall be from standstill to the maximum permissible measuring speed of the vehicle if a
chord-type measuring system is used; if an inertial-type measurement is used, a minimum speed may
be necessary to measure some parameters. The minimum speed should be specified according to the
characteristics of the used system and the needs defined by the infrastructure manager (e.g. for
conventional inertial-type measurement systems usually 10 km/h is necessary for the wavelength
range D1).
5.5.2 Sensors
The sensors shall measure in real time the track geometry parameters or their components. In order to
measure the parameters under track loaded conditions, the sensors placed under the vehicle’s frame
shall be as close as possible to one of the vehicle’s loaded axles to respect measurement conditions
indicated in EN 13848-1. The sensors can be either contact type or non-contact type sensors.
The sensors’ mechanical and electrical characteristics (frequency response, signal-to-noise ratio, gain,
etc.) shall be adequate to enable the generation of track geometry parameters, independently of the
environmental conditions on the railway network.
5.5.3 Signal transmission
Signal transmission consists of all components which are necessary for data interchange between the
sensors and the signal processing unit.
It shall at least comply with the following requirements:
— no phase shift;
— no distortion of results data;
— compliance with appropriate industry-accepted data interchange standards.
The transmission characteristics shall be appropriate to the maximum measuring speed of the track
recording vehicle and the data volume.
5.6 Resolution
The resolution shall be ≤ 0,1 mm for every measured principal track geometric parameter, as defined in
EN 13848-1.
5.7 Signal processing
Signal processing provides the data for some of the track geometry parameters compliant with
EN 13848-1 using signals coming from several sensors. The remaining parameters are calculated from
the output of the signal processing e.g. twist.
The signal processing shall respect the following points:
— sampling: all measurements shall be sampled at equally spaced intervals of preferably 0,25 m or
less but not larger than 0,5 m;
— decolouring: in case of chord measurements the signal shall be decoloured according to
EN 13848-1;
— filtering: the filter characteristics for the wavelength ranges shall be compliant with EN 13848-1
and shall be described. To prevent aliasing of the data the analogue signal shall be filtered in
accordance with the sampling theorem.
5.8 Data processing and analysis
5.8.1 General requirements
The software shall be flexible and modular in order to facilitate modifications, for example filter
implementations or output formats.
An increase in the number of input signals as well as of the number of calculations made shall be
foreseen in the system design.
5.8.2 Parameter generation
The output of signal processing in 5.7 is used to generate all the track parameters as defined in
EN 13848-1.
5.8.3 Data merging
In order to assess the track geometry quality, the track parameters shall be synchronized with track
localization and track features.
5.8.4 Parameter analysis
The track geometry parameters defined in EN 13848-1 are analysed for the quality levels and safety
related limits defined in EN 13848-5.
5.8.5 Preparation for output interfaces
The data processing system shall condition signals and associated information for different outputs:
— data storage;
— parameters visualization;
— track geometry chart;
— threshold exceeding values;
— standard deviation and mean values;
— calibration;
— online plausibility check.
5.9 Data presentation and storage
5.9.1 Operator-interfaces
In order to allow the operator to monitor the track geometry recording system an interface shall be
provided with the following characteristics:
— access to the system configuration parameters e.g. filter coefficients, calibration settings;
— access to all diagnostic information of the measuring system (e.g. laser temperature, raw data,
sensor voltage) in order to detect and analyse malfunctions.
5.9.2 End user-interfaces
Because the end users of the measured data, e.g. permanent way engineers, are basically interested in
the track geometry condition, the end user interface shall at least comprise a graphical and/or text
representation of:
— track geometry parameters;
— threshold values;
— localization data;
— track features.
5.9.3 Output of analysis results
Outputs shall be provided in accordance with requirements stated in EN 13848-1 and 5.8.5 above.
5.9.4 Data transmission
The data shall be transferable using removable storage media, a network or radio link complying with
an industry standard.
5.9.5 Data storage
As a minimum, the following data shall be stored in a prescribed retrievable format:
— measured parameters as described in EN 13848-1;
— results of the parameters analysis described above, including settings, if processing is done on
board;
— localization information linked to measured parameters;
— date and time of the measuring run;
— identification of the measuring vehicle;
— user remarks and actions;
— information of measurement validity.
6 Testing of track geometry recording system
6.1 Introduction
This clause covers actions and procedures, which are necessary to ensure effective operation of both
the measuring devices and the corresponding processing system:
a) Calibration
This ensures an accurate setting of the devices within the track geometry recording system.
b) Validation and adjustment
This demonstrates that the whole system complies with the requirements needed to operate correctly.
Also, this ensures that the system continues to operate correctly during routine operations.
6.2 Calibration
The measuring device shall be calibrated to ensure the continued accuracy of measurements. The
calibration is performed according to a specified process. It shall be carried out by appointment by the
manufacturer or the user.
NOTE Usually the calibration is made before the delivery of the measuring system.
6.3 Validation
6.3.1 Overview
After the calibration of the track geometry recording system, a method based on comparison between
different measurement runs on the same section of track shall be used to validate the recording system.
Validation procedures shall be applied to the following:
— initial testing of a new or modified track geometry recording system;
— after a maintenance or repair operation on the track geometry recording system;
— on regular basis.
Additionally, simplified validation can be applied during normal operation.
There are three kinds of validation:
— static tests (see 6.3.2);
— dynamic tests (see 6.3.3);
— in operation (see 6.3.5).
6.3.2 Static tests
Static tests concern mainly track gauge and cross level measurements. This consists of comparing the
measured value with a defined reference.
6.3.3 Dynamic tests
6.3.3.1 Overview
Dynamic tests concern all track geometry parameters according to EN 13848-1. This consists of
comparing the measured values of consecutive measurement runs performed on the same track section
under identical or varying measurement conditions. For linked parameters, cross checks are also
applicable.
6.3.3.2 Measurement conditions for validation
The track geometry recording system shall meet the requirements of EN 13848-1 in all the following
test conditions:
— normal operation of the recording vehicle as specified by the manufacturer;
— various measuring speeds which shall include at least the minimum and maximum possible
measuring speeds;
— both measuring directions;
— both measuring orientations of the vehicle.
NOTE 1 In some networks the use of measurement vehicles is restricted to limited combinations of measuring
direction and orientation. For these networks only these combinations are considered for the validation.
NOTE 2 The maximum measuring speed is limited by the measuring system, the vehicle, the line speed and any
conditions defined by the network.
If possible also the measurement conditions as stated in 5.2 should be tested.
6.3.3.3 Track conditions for validation
For use on conventional lines, the track geometry recording system shall be tested over a wide range of
track design features: curves of various radii and directions, significant cant, frequent alternation of
curves and straight lines, etc.
The track geometric quality should preferably include standard deviations ranging from class A to class
C as defined in EN 13848-6 for speed range from 120 to 160 km/h.
Due to the risk of high dynamic track responses, specific track sections may be excluded from the
validation as for example:
— class E quality sections for the same speed range;
— track sections that do not conform to plain line (e.g. sidings, switches and crossings…);
— track sections that include degraded components such as loose fasteners.
The total length of the test sections used for validation should not be less than 5 km (typical length:
10 km). For speeds lower than or equal to 40 km/h a shorter total length of the test sections e.g. 1 km
may be used.
A reference track may be used to ensure a better comparability between systems and over time.
Data defining the characteristics, such as curve radii, and geometric quality of the track used for the test
runs shall be provided with the test report.
6.3.3.4 Comparison of different runs
6.3.3.4.1 Overview
Two types of analysis can be carried out:
— comparison of runs of the same recording system;
— comparison of runs of a different recording system.
The statistical analysis of parameter data shall be used to compare recording runs (see 6.3.3.4.3).
The frequency analysis should be used (see 6.3.3.4.4).
Additionally, the uncertainty analysis can be performed (see 6.3.3.4.5).
6.3.3.4.2 Synchronization
To get reliable results when comparing parameters, data synchronization is necessary. Because of the
effects of drift on the measured distance, this drift should be computed and compensated on short
sections of e.g. 200 m length by shifting the signal. All track geometry parameters shall be compensated
by applying the same shift.
Other treatments such as resampling or interpolation may be performed.
6.3.3.4.3 Statistical analysis of parameter data
The calculation shall be made for each parameter to be validated and for each pair of runs used for the
comparison. It consists of the following steps:
— calculation of the differences between the values;
— evaluation of the distribution of the differences for the total length of the test sections;
— calculation of the 95th percentile of the distribution of the absolute differences.
6.3.3.4.4 Frequency analysis of parameter data
Another way to compare two runs is to use frequency analysis such as transfer and coherence functions.
A brief description of these functions is given in Annex A.
With this method it is possible to check the similarity in frequency domain of two measurements of the
same track section. When applying this method a total length of the test sections of at least 5 km should
be used.
The transfer function indicates the distortions existing in frequency domain, and the coherence
function, the degree of reliability for the calculation made on transfer function.
The modulus of the transfer function should be as close as possible to unity and the phase as close as
possible to zero for the wavelength ranges specified in EN 13848-1.
The fixed relationship between the sample size and the wavelength range (D1, D2, D3) in which the
frequency analysis is made should be considered to determine the minimum length of the test section
(see Annex A).
6.3.3.4.5 Measurement uncertainty analysis
The estimation of measurement uncertainty can be used to evaluate the quality of the measurement
system and to determine if the measurement process is fit for its intended use.
A suitable method and limit values for measurement uncertainty are proposed in Annex D.
6.3.3.5 Cross check
Cross checks can be performed in the frequency and in the space domain.
A method for the frequency domain is described in A.3.2 and the results shall comply with the limit
values given in C.4.
A method for the space domain is described in Annex E. Limit values are still an open point due to the
lack of experience.
Examples of linked parameters are longitudinal level of each rail versus cross level or alignment of each
rail versus gauge. Correct filtering of all input parameters has to be taken into account.
6.3.4 Methodology and frequency of the validation tests
6.3.4.1 Overview
Depending on the circumstances different validation tests shall be carried out. They are described in the
following sections.
6.3.4.2 Validation of a new system
6.3.4.2.1 Introduction
This validation is part of the acceptance test of a new measurement system. This also applies to totally
refurbished measuring systems or modifications of the vehicle which have a relevant effect on the
measurement principle e.g. bogie replacement.
The validation of a new measurement system consists of one of the following mandatory tests:
— reference method: full comparison of runs of the same vehicle (see 6.3.4.2.2);
— alternative method: partial comparison of runs of the same vehicle and comparison of runs to track
geometry data obtained by a validated reference measurement system (see 6.3.4.2.3).
Additionally, cross checks shall be applied (see 6.3.3.5).
6.3.4.2.2 Reference method
This method is based on comparisons of runs of the same vehicle. It is the preferred method for track
recording cars.
For each different test configuration (see 6.3.3.2) a run has to be made over a predefined track which
fulfils all the requirements in 6.3.3.3.
For all configurations, reproducibility tests shall be carried out.
Additionally, repeatability tests and uncertainty computation (see Annex D) should be carried out.
New system tests shall comply with the requirements of Annex C.
When testing repeatability and reproducibility, the minimum combination of runs and analyses is
shown in Tables 2 and 3.
For measuring systems able to measure down to standstill, the runs at minimum speed Vmin are
replaced with runs at low speed (at least 5 km/h) containing stops.
The comparison of the runs stated in Table 3 shall be done by applying the comparison methods stated
in 6.3.3.4.2 to 6.3.3.4.4 for every configuration pair separately. Each individual result is compared with
the limit values given in Annex C.
If the maximum measuring speed is ≤ 160 km/h the speeds V1 and V2 are defined as:
— V1 = Vmin and V2 = Vmax.
If the geometry recording system is capable to measure at speed above 160 km/h the Tables 2 and 3
shall be applied twice:
— case 1: on a line with line speed V ≤ 160 km/h: V1 = Vmin and V2 = line speed;
— case 2: secondly on a line which allows maximum measurement speed: V1 = V2 (case 1) and
V2 = Vmax.
Table 2 — Required test conditions
Measuring
Condition number Speed Vehicle orientation
direction
1a V1 A→B
1b V1 A→B
2a V2 A→B
2b V2 A→B
3a V1 A←B
3b V1 A←B
4a V2 A←B
4b V2 A←B
5a V1 A←B
5b V1 A←B
6a V2 A←B
6b V2 A←B
7a V1 A→B
7b V1 A→B
8a V2 A→B
8b V2 A→B
NOTE 1 For Vmin lower than or equal to 40 km/h shorter test sections e.g. 1 km can be used.
NOTE 2 The condition numbers 5a/b to 8a/b are only required if the recording vehicle is capable of
measuring in both orientations.
Table 3 — Required comparisons
Recording vehicle with Recording vehicle with 2
Type of analysis
1 vehicle orientation measuring orientations
Repeatability 1a and 1b 1a and 1b
2a and 2b 2a and 2b
5a and 5b 3a and 3b
6a and 6b 4a and 4b
5a and 5b
6a and 6b
7a and 7b
8a and 8b
Reproducibility 1 and 2 1 and 2
1 and 5 1 and 3
1 and 6 1 and 4
2 and 5 1 and 5
2 and 6 1 and 6
5 and 6 1 and 7
1 and 8
2 and 3
2 and 4
2 and 5
2 and 6
2 and 7
2 and 8
3 and 4
3 and 5
3 and 6
3 and 7
3 and 8
4 and 5
4 and 6
4 and 7
4 and 8
5 and 6
5 and 7
5 and 8
6 and 7
6 and 8
7 and 8
NOTE 1 The condition numbers without a letter mean either condition “a” or condition “b”.
NOTE 2 The condition numbers 5 to 8 are only required if the recording vehicle is capable of
measuring in both orientations.
An example for a practical realization of the test runs for a recording vehicle capable of measuring in
both orientations is shown in Figure 3. This procedure should be repeated on different line categories in
order to cover all track conditions for validation (see 6.3.3.3).
a)
b)
Figure 3 — Example for a practical realization of the test runs
For the determination of the measurement uncertainty according to Annex D additional measuring runs
are necessary.
6.3.4.2.3 Alternative method
In case where the reference method is not applicable (e.g. for unattended measuring systems mounted
on commercial trains) the following procedure can be used for validation of a track geometry recording
system. This method shall consist of two steps:
— repeatability test; and
— comparison with a reference system (validated according to 6.3.4.2.2).
The repeatability test is carried out by pairwise comparisons of runs within a narrow time span (in
order to avoid the effects of track deterioration). The test shall cover the whole range of operational
conditions according to the intended usage of the track geometry recording system. The track sections
shall meet the requirements described in 6.3.3.3. The comparison of the runs shall be done by applying
the comparison methods stated in 6.3.3.4.2 to 6.3.3.4.4 for every configuration pair separately. Each
individual result shall comply with the limit values for repeatability given in C.2.
In order to replace the reproducibility test of the reference method, the measuring results used in the
repeatability test shall be compared with measuring results of a fully validated reference measuring
system (reference signals). The comparisons shall be carried out for all track sections of the
repeatability test by calculating the mean of pairwise measuring signals of the tested system and
comparing them with the reference signals according to the methods described in 6.3.3.4.2 to 6.3.3.4.4.
Each individual result should comply with the limit values for reproducibility given in C.3. In order to
improve the reliability of the reference signal averaging of multiple runs can be used.
NOTE Due to the lack of experience no limit values for the comparison with the reference system are
provided as requirement.
In order to identify possible offsets due to different measuring conditions an additional analysis shall be
performed. This shall be done by computing the distributions of the differences between the mean
measurement signals and the reference signals according to 6.3.3.4.3. The distributions shall be
compared separately for different running configurations (e.g. low and high speed, forward and reverse
orientations) in order to determinate possible offsets.
Measuring systems validated by this alternative method shall not be used as a reference system for
validation of other track geometry recording systems.
6.3.4.3 Simplified validation
A simplified validation shall be carried out in accordance with the manufacturer’s maintenance manual
in the following circumstances:
— after a maintenance or repair operation which may affect the measuring system, e.g. sensor
replacement;
— at least once a year.
The simplified validation consists of a comparison of runs of the same vehicle.
If possible, a comparison with a validated reference measuring system is recommended.
For repeatability and reproducibility, the minimum combination of runs and analyses shown in Tables 4
and 5 shall be carried out. The comparison of the runs stated in Table 3 shall be done according to
6.3.3.4.
In addition, static tests shall be carried out for example to ensure that there are no offsets in the
measurement of cross level and track gauge.
If the maximum measuring speed is ≤ 160 km/h the speeds V1 and V2 are defined as:
— V1 = Vmin and V2 = Vmax.
If the geometry recording system is capable to measure at speed above 160 km/h the Tables 4 and 5
shall be applied twice:
— case 1: on a line with line speed V ≤ 160 km/h: V1 = Vmin and V2 = line speed;
— case 2: secondly on a line which allows maximum measurement speed: V1 = V2 (case 1) and
V2 = Vmax.
Table 4 — Required test conditions
Measuring
Condition number Speed Vehicle orientation
direction
1a V1 A→B
1b V1 A→B
2a V2 A→B
2b V2 A→B
3 V1 A←B
4 V2 A←B
5 V1 A←B
6 V2 A←B
NOTE 1 For Vmin lower than or equal to 40 km/h shorter test sections e.g. 1 km can be used.
NOTE 2 The condition numbers 5 and 6 are only required if the recording vehicle is capabl
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