SIST ENV 14028:2001
(Main)Hydrometry - The application of propeller-type current meters and their calibration
Hydrometry - The application of propeller-type current meters and their calibration
This European Prestandard specifies the operational requirements, calibration and maintenance of propeller-type devices for the measurement of flow velocities in open channels. The requirements of the calibration facility are laid down. The result of calibration is the relationship between water velocity and rate of revolution of the propeller.
This European Prestandard does not define the form of the signal produced by the equipment or the signal receiving equipment.
Hydrometrie - Anwendung von Fließgeschwindigkeitsmessen mit Geschwindigkeitsmessflügeln und ihre Kalibrierung
Anwendungsbereich
Diese Europäische Vornorm legt die Betriebsanforderungen, die Kalibrierung und die Wartung für Geräte mit Geschwindigkeitsmessflügeln zur Messung von Fließgeschwindigkeiten in offenen Kanälen fest. Die Anforderungen an die Kalibriereinrichtung werden festgelegt. Das Ergebnis der Kalibrierung ist das Verhältnis zwischen Wassergeschwindigkeit und Umlaufgeschwindigkeit des Messflügels.
Diese Europäische Vornorm legt nicht die Art des durch das Gerät erzeugten Mess-Signals oder des Empfängergeräts für das Mess-Signal fest.
Hydrométrie - Techniques opératoires pour l'étalonnage des moulinets hydrométriques a hélice
Domaine d'application
La présente norme européenne définit les conditions opérationnelles d'étalonnage et de maintenance des moulinets hydrométriques à hélice mis en ¿uvre pour le mesurage des vitesses de fluides dans les chenaux découverts. Les conditions requises pour effectuer un étalonnage sont définies. Le résultat de l'opération d'étalonnage est la relation qui fait correspondre la vitesse de l'écoulement à la vitesse de rotation de l'hélice.
La présente norme européenne ne décrit ni le signal engendré ni le dispositif enregistreur de ce signal.
Hidrometrija - Uporaba turbinskih pretočnih meril in njihova kalibracija
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-november-2001
+LGURPHWULMD8SRUDEDWXUELQVNLKSUHWRþQLKPHULOLQQMLKRYDNDOLEUDFLMD
Hydrometry - The application of propeller-type current meters and their calibration
Hydrometrie - Anwendung von Fließgeschwindigkeitsmessen mit
Geschwindigkeitsmessflügeln und ihre Kalibrierung
Hydrométrie - Techniques opératoires pour l'étalonnage des moulinets hydrométriques a
hélice
Ta slovenski standard je istoveten z: ENV 14028:2001
ICS:
17.120.20 Pretok v odprtih kanalih Flow in open channels
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN PRESTANDARD
ENV 14028
PRÉNORME EUROPÉENNE
EUROPÄISCHE VORNORM
April 2001
ICS 17.120.20
English version
Hydrometry - The application of propeller-type current meters
and their calibration
This European Prestandard (ENV) was approved by CEN on 7 March 2001 as a prospective standard for provisional application.
The period of validity of this ENV is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the ENV can be converted into a European Standard.
CEN members are required to announce the existence of this ENV in the same way as for an EN and to make the ENV available promptly
at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the ENV) until the final
decision about the possible conversion of the ENV into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2001 CEN All rights of exploitation in any form and by any means reserved Ref. No. ENV 14028:2001 E
worldwide for CEN national Members.
Page 2
Contents
Page
Foreword .3
1 Scope.4
2 Normative References.4
3 Terms and definitions .4
4 Principle of operation and calibration.4
5 Operational requirements .5
5.1 Positioning.5
5.2 Limits of use .5
5.3 Maintenance.6
5.4 Operating and service manual.6
6 Calibration .6
6.1 Frequency of calibration .6
6.2 Effect of suspension .6
6.3 Calibration tank.6
6.3.1 Cross-section.7
6.3.2 Length of the calibration tank.7
6.4 Guide system for the rating carriage.7
6.5 Rating carriage .7
6.6 Measuring devices.8
6.6.1 Measurement of distance .8
6.6.2 Measurement of time.8
6.6.3 Pulse counting.8
7 Calibration procedure .8
7.1 Condition of the current meter to be calibrated .8
7.2 Suspension of the current meter.8
7.3 Depth of immersion .8
7.4 Simultaneous towing of several current meters .8
7.5 Oscillations .9
7.6 Calibration runs .9
7.6.1 Minimum response speed .9
7.6.2 Number of calibration runs.9
7.6.3 Stilling time .9
8 Evaluation and presentation of the calibration results.9
8.1 Storage of the measurement data during calibration .9
8.2 Presentation of the measurement series .9
8.3 Equations of the measurement series .9
8.4 Limits of application of the rating equations .9
8.5 Calibration certificate .10
Bibliography.11
Page 3
Foreword
This European Standard has been prepared by Technical Committee CEN/TC 318 "Hydrometry", the secretariat of
which is held by BSI.
The text of the International Standard ISO 2537 : 1988 has been modified by the Technical Committee CEN/TC 318
"Hydrometry", which has decided to submit this European Standard for approval as an ENV.
This standard includes a Bibliography.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this European Prestandard: Austria, Belgium, Czech Republic, Denmark, Finland,
France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden,
Switzerland and the United Kingdom.
Page 4
1 Scope
This European Prestandard specifies the operational requirements, calibration and maintenance of propeller-
type devices for the measurement of flow velocities in open channels. The requirements of the calibration facility
are laid down. The result of calibration is the relationship between water velocity and rate of revolution of the
propeller.
This European Prestandard does not define the form of the signal produced by the equipment or the signal
receiving equipment.
2 Normative References
This European Prestandard incorporates by dated or undated reference, provisions from other publications.
These normative references are cited at the appropriate places in the text and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply to
this European Prestandard only when incorporated in it by amendment or revision. For undated references the
latest edition of the publication referred to applies (including amendments).
ISO 772 : 1996
Hydrometric determinations – Vocabulary and symbols
3 Terms and definitions
For the purposes of this European Standard, the terms and definitions given in ISO 772 :1996 apply.
4 Principle of operation and calibration
The propeller of a current meter is driven by the fluid at an angular velocity which is a function of the local
velocity of the fluid at the point of immersion when that velocity exceeds a critical value.
The axis of the propeller should be parallel to the direction of flow.
The calibration procedure consists of towing the current meter through still water at a number of known
velocities, at which the precise rate of revolution is determined after a constant speed has been reached. The
rate of revolution of the propeller, the time taken, and distance travelled are measured when the current meter is
travelling at constant speed. The rates of revolution of the propeller are related to the speed of the rating
carriage by means of one or more equations, for which the limits of application are given.
Page 5
Key
1 Rod
2 Current meter mounted by screw
3 Slide support
4 Cable transmitting the signals
5 Direction of flow
6 Body of the current meter
7 Distance pin for protection of the propeller
8 Propeller
Figure 1 - Propeller-type Current Meter
(rod suspension)
5 Operational requirements
5.1 Positioning
The equipment should maintain alignment with the flow in such a way that the propeller responds to flow
movement as intended. If a pivoted suspension is incorporated within the current meter, it should permit
freedom in the vertical plane to ensure correct alignment with the liquid flow. Alignment in the horizontal plane
may be affected by the correct choice of suspension equipment.
Current meters of conventional construction are intended to operate in a horizontal or near-horizontal position.
Current meters designed to operate in other positions are not covered by this European Standard.
5.2 Limits of use
The propeller of the current meter shall be such that, when driven by the fluid, it rotates at an angular velocity
which has a known relationship to the velocity of the flow within the calibrated velocity range stated by the
Page 6
manufacturer of the current meter or rating laboratory.
The suspension system used shall be as specified by the manufacturer of the current meter.
The current meter shall be used only in liquids with properties similar to those in which the meter was calibrated.
If the liquid properties are significantly different, the meter shall be recalibrated in a liquid with properties similar
to that in which the meter is to be used.
Unless otherwise indicated, the current meter shall be capable of being used in waters containing suspended
sediment and in saline waters.
The manufacturer shall state the maximum hydrostatic pressure to which the instrument may be subjected.
5.3 Maintenance
Under conditions of normal operation, the user shall follow recommended check procedures before and after
each discharge measurement, as laid down in the manufacturer's operation and service manual.
Spare parts shall be fully interchangeable so as to have uniform functional characteristics. The manufacturer
shall state the maximum uncertainty introduced by fitting a replacement part.
5.4 Operating and service manual
A comprehensive operating and servicing manual shall be supplied with each instrument. It shall present full
instructions, illustrated where necessary, and include appropriate circuit diagrams with component values.
6 Calibration
6.1 Frequency of calibration
Meters shall be recalibrated whenever their performance is suspect. The use of a reference current meter is
recommended for early diagnosis of a fault occurring in the performance of the current meter. In practice, for
individually rated meters, recalibration is sometimes carried out at two yearly intervals or after 300 h of use,
whichever is the shorter.
6.2 Effect of suspension
The performance of a meter may be affected by its mode of suspension and the sounding weight used. For
individual ratings, it is advisable that the calibration be carried out using the means of suspension and the
sounding weight intended to be used during a measurement. The distances from the bottom, the top and the
side walls of the calibration tank to the meter, for the calibrated configuration, shall be specified by the rating
laboratory or manufacturer.
It is possible to derive by experiment coefficients which can be applied to gauging data to correct for the effects
(if any) of different sounding weights and different types, size, and shape of suspension.
Such coefficients are applicable only to the specific combination for which data have been experimentally
obtained.
6.3 Calibration tank
The dimensions of the calibration tank will influence calibration and also limit the number of instruments that can
be towed simultaneously. The cross-section of the tank shall be identical along the entire length of travel.
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