Performance characteristics and calibration methods for digital data acquisition systems and relevant software

Specifies performance characteristics and calibration methods for digital data acquisition systems and relevant software to ensure that all measurement systems relying on DAQ devices meet a common standard. This standard covers: - the minimum specifications that the DAQ device manufacturer must provide to describe the performance of the analogue-to-digital module (ADM) of the DAQ device; - standard test strategies to verify the minimum set of specifications; - the minimum calibration information required by the ADM that is stored on the DAQ device; - the minimum calibration software requirements for external and self-calibration of the ADM of the DAQ device. This standard deals with low frequency signal conversion, e.g. applications such as plant control, vibration measurement, vibro-diagnostics, acoustics, ultrasonic measurements, temperature measurements, pressure measurements, measurement in power electronics, etc.

Leistungseigenschaften und Kalibrierverfahren für digitale Datenerfassungssysteme und entsprechende Software

Caractéristiques de performance et méthodes d'étalonnage pour les systèmes d'acquisition de données numériques et logiciels appropriés

Spécifie des caractéristiques de performances et des méthodes d'étalonnage destinées aux systèmes d'acquisition de données numériques et aux logiciels appropriés, de manière à assurer que tous les systèmes de mesure basés sur des dispositifs d'acquisition de données multifonction (DAQ) répondent à une norme commune. La présente norme couvre: - les spécifications minimales que le constructeur du dispositif DAQ doit fournir pour décrire les performances du Module Analogique-Numérique (MAN) du dispositif DAQ. - les stratégies d'essai normalisées pour vérifier l'ensemble minimal de spécifications. - les informations minimales relatives à l'étalonnage, exigées par le MAN, et stockées sur le dispositif DAQ. - les exigences minimales relatives au logiciel de calibrage pour le calibrage externe et l'auto-calibrage du MAN du dispositif DAQ. La présente norme traite de conversion de signal de basse fréquence par exemple les applications telles que le contrôle d'usine, la mesure de vibrations, les vibro-diagnostics, les mesures acoustiques, ultrasoniques, de température, de pression, la mesure en électronique de puissance, etc.

Karakteristike delovanja in postopki kalibracije sistemov za zajemanje digitalnih podatkov in pripadajoče programske opreme (IEC 62008:2005)

General Information

Status
Published
Publication Date
19-Oct-2005
Current Stage
6060 - Document made available
Due Date
20-Oct-2005
Completion Date
20-Oct-2005

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SLOVENSKI STANDARD
SIST EN 62008:2006
01-september-2006

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SRGDWNRYLQSULSDGDMRþHSURJUDPVNHRSUHPH ,(&

Performance characteristics and calibration methods for digital data acquisition systems

and relevant software

Leistungseigenschaften und Kalibrierverfahren für digitale Datenerfassungssysteme und

entsprechende Software
Caractéristiques de performance et méthodes d'étalonnage pour les systèmes
d'acquisition de données numériques et logiciels appropriés
Ta slovenski standard je istoveten z: EN 62008:2005
ICS:
35.080
35.160
SIST EN 62008:2006 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
EUROPEAN STANDARD EN 62008
NORME EUROPÉENNE
EUROPÄISCHE NORM October 2005
ICS 33.200
English version
Performance characteristics and calibration methods
for digital data acquisition systems
and relevant software
(IEC 62008:2005)
Caractéristiques de performance Leistungseigenschaften
et méthodes d'étalonnage und Kalibrierverfahren
pour les systèmes d'acquisition für digitale Datenerfassungssysteme
de données numériques und entsprechende Software
et logiciels appropriés (IEC 62008:2005)
(CEI 62008:2005)

This European Standard was approved by CENELEC on 2005-10-01. CENELEC 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 Central Secretariat or to any CENELEC 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 CENELEC member into its own language and

notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech

Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,

Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,

Switzerland and United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 62008:2005 E
---------------------- Page: 2 ----------------------
EN 62008:2005 - 2 -
Foreword

The text of document 85/267/FDIS, future edition 1 of IEC 62008, prepared by IEC TC 85, Measuring

equipment for electrical and electromagnetic quantities, was submitted to the IEC-CENELEC parallel

vote and was approved by CENELEC as EN 62008 on 2005-10-01.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2006-07-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2008-10-01
Annex ZA has been added by CENELEC.
__________
Endorsement notice

The text of the International Standard IEC 62008:2005 was approved by CENELEC as a European

Standard without any modification.
__________
---------------------- Page: 3 ----------------------
- 3 - EN 62008:2005
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications

The following referenced documents are indispensable for the application 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.

NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant

EN/HD applies.
Publication Year Title EN/HD Year
IEC 60748-4 1997 Semiconductor devices - Integrated - -
circuits
Part 4: Interface integrated circuits
IEC 60748-4-3 - Part 4-3: Interface integrated circuits - - -
Dynamic criteria for Analogue-Digital
Converters (ADC)
2) 3)
ISO/IEC 17025 - General requirements for the competence EN ISO/IEC 2005
of testing and calibration laboratories 17025
BIPM/IEC/IFCC/ISO/
- Guide to the expression of uncertainty in - -
IUPAC/IUPAP/OIML
measurement (GUM)
To be published.
Undated reference.
Valid edition at date of issue.
---------------------- Page: 4 ----------------------
NORME CEI
INTERNATIONALE
IEC
62008
INTERNATIONAL
Première édition
STANDARD
First edition
2005-07
Caractéristiques de performance et
méthodes d'étalonnage pour les systèmes
d'acquisition de données numériques
et logiciels appropriés
Performance characteristics and calibration
methods for digital data acquisition systems
and relevant software
 IEC 2005 Droits de reproduction réservés  Copyright - all rights reserved

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électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from

microfilms, sans l'accord écrit de l'éditeur. the publisher.

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Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch Web: www.iec.ch

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Pour prix, voir catalogue en vigueur
For price, see current catalogue
---------------------- Page: 5 ----------------------
62008  IEC:2005 – 3 –
CONTENTS

FOREWORD...........................................................................................................................7

INTRODUCTION...................................................................................................................11

1 Scope.............................................................................................................................13

2 Normative references .....................................................................................................13

3 Terms, definitions, abbreviations and symbols................................................................15

3.1 Terms and definitions ............................................................................................15

3.2 Abbreviations and symbols....................................................................................17

4 General requirements .....................................................................................................17

4.1 Test procedures and measurement uncertainty estimation ....................................17

4.2 General requirements for ADMs ............................................................................19

4.3 Descriptions of parameters....................................................................................19

4.4 Testing methods of measurable parameters ..........................................................27

5 Hardware functionality for calibration..............................................................................51

5.1 Onboard calibration information.............................................................................51

5.2 General measurement adjustment hardware..........................................................51

5.3 Self-adjustment hardware......................................................................................53

6 Software calibration methods..........................................................................................53

6.1 Calibration application programming interface (API) ..............................................53

6.2 Self-calibration methods ........................................................................................53

6.3 External calibration methods .................................................................................55

7 Calibration procedures ...................................................................................................55

Annex A (informative) Examples of calculation of modular DAQ system uncertainty.............57

Annex B (normative) Pseudo-code to perform static test by method B (see 4.4.1.2)

and a numerical example ......................................................................................................63

Annex C (informative) ADM characteristics ..........................................................................83

Bibliography..........................................................................................................................93

Figure 1 – Test signals applied to the ADM...........................................................................31

Figure 2 – Test procedure.....................................................................................................35

Figure 3 – Representation in different grey tones of the cumulative histograms

computed in each step in the case of a 5-bit ADM and a test with 4 steps.............................35

Figure 4 – Test arrangement for noise measurements on ADMs ...........................................43

Figure C.1 – Bipolar ADM with true zero ...............................................................................85

Figure C.2 – Bipolar ADM with no true zero ..........................................................................87

Figure C.3 – Offset (specified at step 000)............................................................................89

Figure C.4 – Gain component of uncertainty (after correction of offset) (specified at

step 011) ..............................................................................................................................91

---------------------- Page: 6 ----------------------
62008  IEC:2005 – 5 –

Table 1 – Precision of estimates of code transition level for different record lengths ............29

Table 2 – Example of parameters specification of ADM for measurement uncertainty

estimation of DAQ device......................................................................................................49

Table B.1 – Derivation of the amplitude (A) and offset (C ) of the small triangular waves,

the number of samples per record (M) and the number of records (R). ..................................73

Table B.2 – Results of the histogram test and corresponding transition voltages for a

5-bit ADM tested by method B in 4 steps ..............................................................................75

Table B.3 – Deriving INL and DNL from the measured transition voltages.............................79

---------------------- Page: 7 ----------------------
62008  IEC:2005 – 7 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PERFORMANCE CHARACTERISTICS AND CALIBRATION METHODS
FOR DIGITAL DATA ACQUISITION SYSTEMS
AND RELEVANT SOFTWARE
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

all national electrotechnical committees (IEC National Committees). The object of IEC is to promote

international co-operation on all questions concerning standardization in the electrical and electronic fields. To

this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,

Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC

Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested

in the subject dealt with may participate in this preparatory work. International, governmental and non-

governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely

with the International Organization for Standardization (ISO) in accordance with conditions determined by

agreement between the two organizations.

2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international

consensus of opinion on the relevant subjects since each technical committee has representation from all

interested IEC National Committees.

3) IEC Publications have the form of recommendations for international use and are accepted by IEC National

Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC

Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any

misinterpretation by any end user.

4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications

transparently to the maximum extent possible in their national and regional publications. Any divergence

between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in

the latter.

5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any

equipment declared to be in conformity with an IEC Publication.

6) All users should ensure that they have the latest edition of this publication.

7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and

members of its technical committees and IEC National Committees for any personal injury, property damage or

other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and

expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC

Publications.

8) Attention is drawn to the normative references cited in this publication. Use of the referenced publications is

indispensable for the correct application of this publication.

9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of

patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 62008 has been prepared by IEC technical committee 85:

Measuring equipment for electrical and electromagnetic quantities.
The text of this standard is based on the following documents:
FDIS Report on voting
85/267/FDIS 85/268/RVD

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

---------------------- Page: 8 ----------------------
62008  IEC:2005 – 9 –

The committee has decided that the contents of this publication will remain unchanged until

the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in

the data related to the specific publication. At this date, the publication will be

• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
---------------------- Page: 9 ----------------------
62008  IEC:2005 – 11 –
INTRODUCTION

Totally automated measurement systems are becoming the norm for manufacturing test,

research and any other area where measurements are made. Measurement automation leads

to extensive data sharing, inter-instrument communication and remote measurement control.

Multifunction data acquisition (DAQ) devices meet these measurement needs. They rely on

standard computer technology, allowing measurement systems developers to leverage open

computer standards. The measurements made by DAQ devices are accurate and traceable.

The need for measurement integrity requires developing standards not only for the

measurement hardware but also for the software that calibrates the hardware.
---------------------- Page: 10 ----------------------
62008  IEC:2005 – 13 –
PERFORMANCE CHARACTERISTICS AND CALIBRATION METHODS
FOR DIGITAL DATA ACQUISITION SYSTEMS
AND RELEVANT SOFTWARE
1 Scope

This International Standard specifies performance characteristics and calibration methods for

digital data acquisition systems and relevant software to ensure that all measurement

systems relying on DAQ devices meet a common standard.
This standard covers:

– the minimum specifications that the DAQ device manufacturer must provide to describe

the performance of the analogue-to-digital module (ADM) of the DAQ device;
– standard test strategies to verify the minimum set of specifications;

– the minimum calibration information required by the ADM that is stored on the DAQ device;

– the minimum calibration software requirements for external and self-calibration of the

ADM of the DAQ device.

This standard deals with low frequency signal conversion, e.g. applications such as plant

control, vibration measurement, vibro-diagnostics, acoustics, ultrasonic measurements,

temperature measurements, pressure measurements, measurement in power electronics, etc.

2 Normative references

The following referenced documents are indispensable for the application 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.

IEC 60748-4:1997, Semiconductor devices – Integrated circuits – Part 4: Interface integrated

circuits

IEC 60748-4-3:___ , Semiconductor devices – Integrated circuits – Part 4-3: Interface

integrated circuits – Dynamic criteria for analogue-to-digital converters (ADC)

ISO/IEC 17025, General requirements for the competence of testing and calibration

laboratories

BIPM, IEC, IFCC, ISO, IUPAC, IUPAP, OIML, Guide to the Expression of Uncertainty in

Measurement (GUM)
———————
To be published.
---------------------- Page: 11 ----------------------
62008  IEC:2005 – 15 –
3 Terms, definitions, abbreviations and symbols
3.1 Terms and definitions
For the purposes of this document, the following definitions apply.
3.1.1
analogue-to-digital module
ADM
analogue input of a multifunction DAQ device
3.1.2
application program interface
API

standardized set of subroutines or functions along with the parameters that a program can call.

An API for DAQ devices allows the programmer to communicate and control the operation of

the device
3.1.3
code transition level

value of the input parameter of an ADM at the transition point between two adjacent output

codes. The transition point is defined as the input value that causes 50 % of the output codes

to be less than and 50 % to be greater than or equal to the upper code of the transition. The

transition level T[k] lies between code k -1 and code k
3.1.4
data acquisition device
DAQ
device for entering or collecting data

NOTE Multifunction DAQ devices rely on a personal computer (commercial PC, Industrial PC, Compact PCI,

notebook etc.) for control. These devices are designed to meet the needs of a general-purpose measurement

system. They are not designed for a specific type of measurement. DAQ devices generally provide multiple

measurement modes such as analogue input, analogue output, digital input, digital output, and counter-timer

functionality. This standard only deals with the ADM of a DAQ device.
3.1.5
midstep value

analogue value for the centre of the step excluding the steps at the two ends of the total

range of analogue values

NOTE For the end steps, the midstep value is defined as the analogue value that results when the analogue value

for the transition to the adjacent step is reduced or enlarged as appropriate by half the nominal value of the step

width.
3.1.6
nominal midstep value

specified analogue value within a step that is ideally represented and free of error by the

corresponding digital output code
3.1.7
rated operating conditions

set of conditions that must be fulfilled during the measurement in order that the parameters

determining the measurement uncertainty may be valid.
---------------------- Page: 12 ----------------------
62008  IEC:2005 – 17 –
3.1.8
step

the fractional range of analogue input values and the corresponding digital output value.

3.1.9
step width

the absolute value of the difference between the two ends of the range of analogue values

corresponding to one step.
3.2 Abbreviations and symbols
ADM Analogue to digital module
API Application program interface
CMRR Common mode rejection ratio
DAQ Data acquisition device
DIFF Differential
DNL Differential non-linearity
ENOB Effective number of bits
FS Full scale
INL Integral non-linearity
LSB Least significant bit
NRSE Non-referenced single ended
PC Personal computer
RSE Referenced single ended
SINAD Signal to noise and distortion
SFDR Spurious free dynamic range
V Full scale
V Nominal full scale range
FSnom
V Practical full scale range
FSR
V Zero
V Zero scale
4 General requirements
4.1 Test procedures and measurement uncertainty estimation

A common set of specifications must be presented for comparing the ADM of one DAQ device

to the ADM of another DAQ device. This is especially true when different manufacturers

produce the ADMs. This document includes a core set of information that allows a side-by-

side comparison of ADM capabilities.

DAQ devices are designed to meet their published specifications. If there is a need to verify

these specifications, this standard presents procedures for testing the ADM to confirm the

specifications of the DAQ device.

Using the specifications listed in 4.2, the measurement uncertainty of the ADM of a DAQ

device can be determined.
---------------------- Page: 13 ----------------------
62008  IEC:2005 – 19 –
4.2 General requirements for ADMs

The required specifications listed below are a minimum subset of the possible specifications.

The basic parameters describing an ADM include:
– number of channels;
– types of inputs;
– full-scale input range;
– overvoltage protection;
– resolution;
– sampling rate;
– input impedance;
– maximum working voltage;
– rated operating conditions.
The measurable parameters that can be tested include the following :
– gain component of uncertainty;
– offset;
– common mode rejection ratio;
– temperature drift of gain and offset;
– integral non-linearity;
– differential non-linearity;
– noise;
– settling time;
– channel switching error;
– crosstalk;
– analogue input bandwidth.
Where appropriate the following parameters apply:
– signal-to-noise and distortion ratio (SINAD);
– effective number of bits (ENOB);
– spurious free dynamic range (SFDR);
– total harmonic distortion (THD);
– signal to non-harmonic ratio (SNHR).
4.3 Descriptions of parameters
NOTE It is assumed that the input value measured is voltage.
4.3.1 Number of channels

The number of input signals supported by the ADM that can be simultaneously or sequentially

sampled.
———————

Other requirements specific for medium and high frequencies are treated by IEC 60748-4-3.

---------------------- Page: 14 ----------------------
62008  IEC:2005 – 21 –
4.3.2 Types of input

Type of input defines how input signals can be connected to the ADM. Possible modes

include:

– referenced single ended (RSE) – an RSE connection is one in which the DAQ device’s

analogue input signal is referenced to a common ground that can be shared with other

input signals;

– non-referenced single ended (NRSE) – an NRSE connection is one in which the DAQ

device’s analogue input signal is referenced to the signal local ground. In this case the

local ground must be different from the analogue ground of the measurement system;

– differential (DIFF) – a DIFF connection is one in which the DAQ device’s analogue input

signal has its own reference signal or signal return path. An ADM with DIFF inputs may

specify input impedance as the impedance between the positive input and negative input

of the ADM. An ADM with DIFF inputs may also specify input impedance as the impedance

between either the positive input and ground or the negative input and ground.
4.3.3 Full-scale input range

The full-scale input range is the total range in analogue values that theoretically can be coded

with constant accuracy by the total number of steps. The full-scale input range is expressed in

volts (see 2.1.18 of IEC 60748-4, Chapter II). Refer to V in Figures C.1 and C.2.

FSnom
4.3.4 Overvoltage protection

Overvoltage protection is the protection of the input circuitry of an ADM from potentially

damaging voltages. Overvoltage protection can be shown for the powered on and powered off

states of the DAQ device. Overvoltage protection is expressed in volts.
4.3.5 Resolution

The degree to which nearly equal values of the analogue input quantity can be distinguished

(see 2.2.1 of IEC 60748-4, Chapter II).

NOTE 1 Numerical resolution is the number (n) of bits necessary to express the total number of steps (see 2.2.2

of IEC 60748-4, Chapter II).

NOTE 2 Analogue resolution (Q) is the nominal value of the step width (see 2.2.3 of IEC 60748-4, Chapter II).

4.3.6 Sampling rate

The number of conversions per unit time. Sampling rate is usually expressed in samples per

second.
4.3.7 Gain component of uncertainty

The difference between the actual and the ideal transition voltages in the transfer diagram at

the specified gain point, after the offset has been adjusted to zero. Gain component of

uncertainty is expressed in % of full-scale input range and should include the warranted time

interval of calibration (see 2.2.5.3 of IEC 60748-4, Chapter II).
---------------------- Page: 15 ----------------------
62008  IEC:2005 – 23 –
4.3.8 Offset

The difference between the actual and the ideal first transition levels (see Figure C.3). Offset

is expressed in the units of measure for the ADM and should include the warranted time

interval of calibration (see 2.2.5.2 of IEC 60748-4, Chapter II).

NOTE The first transition level is the transition level where the ADM output changes from 0 to 1. See 3.1.3 for the

definition of code transition level.
4.3.9 Common mode rejection ratio (CMRR)

The ratio of the voltage applied between a specified reference point and the input terminals of

the ADM, when connected together by a specified circuit, to the voltage required between the

input terminals of the ADM to produce the same output.

NOTE The common mode rejection ratio is usually expressed in decibels and may depend upon frequency.

4.3.10 Input impedance

Input impedance is the impedance between the signal input of the ADM and signal common.

Input impedance must be specified when the ADM is powered on, powered off, and when

isolated input limits are overloaded (if applicable).
4.3.11 Temperature drift of gain and offset

Temperature drift of gain is expressed in % of full scale input range per degree Celsius.

Temperature drift of offset is expressed in units of measure for the ADM per degree Celsius.

4.3.12 Integral non-linearity (INL)

The difference between the actual analogue value at the transition between any two adjacent

steps and its ideal value, after offset and gain component of uncertainty have been adjusted

to zero. Integral non-linearity describes the difference between the actual value and the ideal

value of the analogue quantity. INL is expressed in LSB.
4.3.13 Differential non-linearity (DNL)

The difference between the actual step width and the ideal value. DNL is expressed in LSB.

4.3.14 Maximum working voltage

Maximum working voltage is the highest voltage that should be applied to an ADM in normal

use. The working voltage is normally well under the breakdown voltage for safety margin. The

maximum working voltage is the sum of the actual signal voltage and the common mode

voltage and is expressed in volts.
4.3.15 Noise

Noise is any deviation between the ADM output signal (converted to input units) and the ADM

input signal except for deviations caused by linear time invariant system response (gain and

phase shift), a DC level shift, or a deviation in the sample rate. For example, noise includes

the effects of random deviations, fixed pattern deviations, nonlinearities, time base deviations

(fixed deviation in sample time and aperture uncertainty, also known as jitter) and the

---------------------- Page: 16 ----------------------
62008  IEC:2005 – 25 –

undesirable infiltration of internal digital signals to the analogue part. Noise is expressed in

the units of measure for the ADM.

NOTE 1 For DC or very low frequency input signals it is usual to describe system noise as measured in 4.4.7,

which does not include the effect of non-linearity and time base deviations.

NOTE 2 SINAD and ENOB include the effects of non-linearity and time base deviations.

4.3.16 Settling time for single channel measurements

The time it takes the ADM to reach a certain accuracy and stay within that accuracy. Settling

time is expressed in seconds required to achieve the given accuracy range. Settling time for

single channel measurements is defined for an ADM measuring a step signal on a si

...

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