SIST-TP CEN/TR 17993:2023

Calibration and accuracy of non-catching precipitation measurement instruments

Non-catching type gauges are the emerging class of in situ precipitation measurement instruments. For these instruments, rigorous testing and calibration are more challenging than for traditional gauges. Hydrometeors’ characteristics like particle size, shape, fall velocity and density need to be reproduced in a controlled environment to provide the reference precipitation, instead of the equivalent water flow used for catching-type gauges. They are generally calibrated by the manufacturers using internal procedures developed for the specific technology employed. No agreed methodology exists, and the adopted procedures are rarely traceable to internationally recognized standards. This document describes calibration and accuracy issues of non-catching instruments used for liquid/solid atmospheric precipitation measurement. An overview of the existing models of non-catching type instruments is included, together with an overview and a description of their working principles and the adopted calibration procedures. The literature and technical manuals disclosed by manufacturers are summarized and discussed, while current limitations and metrological requirements are identified.

Kalibrierung und Genauigkeit von nicht auffangenden Niederschlagsmessgeräten

Étalonnage et précision des pluviomètres sans captage

Kalibracija in točnost instrumentov za merjenje padavin brez njihovega zajemanja

Merilniki brez funkcije zajemanja so nov razred instrumentov za merjenje padavin na mestu uporabe. Strogo preskušanje in kalibracija sta pri teh instrumentih zahtevnejša kot pri tradicionalnih merilnikih. Značilnosti hidrometeorjev, kot so velikost delcev, oblika, hitrost padca in gostota, je namesto enakovrednega pretoka vode, ki se uporablja za merilnike s funkcijo zajemanja, treba reproducirati v nadzorovanem okolju, da se zagotovijo referenčne padavine. Običajno jih kalibrirajo proizvajalci z notranjimi postopki, ki so razviti za specifično uporabljeno tehnologijo. Dogovorjena metodologija ne obstaja, sprejeti postopki pa so redko sledljivi do mednarodno priznanih standardov. Ta dokument opisuje težave v zvezi s kalibracijo in točnostjo instrumentov brez funkcije zajemanja, ki se uporabljajo za merjenje atmosferskih padavin v tekočem/trdnem stanju. Vključuje pregled obstoječih modelov instrumentov brez funkcije zajemanja ter pregled in opis načinov njihovega delovanja ter sprejetih postopkov kalibracije. V dokumentu so povzeti in obravnavani literatura in tehnični priročniki, ki so jih navedli proizvajalci, ter opredelitve trenutnih omejitev in meroslovne zahteve.

General Information

• Status: Published
• Publication Date: 01-Nov-2023
• ICS: 07.060 - Geology. Meteorology. Hydrology
• ICS: 17.120.20 - Flow in open channels
• Technical Committee: IMIN - Measurement instruments
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 26-Oct-2023
• Due Date: 31-Dec-2023
• Completion Date: 02-Nov-2023
• Ref Project: CEN/TR 17993:2023 - Calibration and accuracy of non-catching precipitation measurement instruments

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TP CEN/TR 17993:2023
01-december-2023
Kalibracija in točnost instrumentov za merjenje padavin brez njihovega zajemanja
Calibration and accuracy of non-catching precipitation measurement instruments
Kalibrierung und Genauigkeit von nicht auffangenden Niederschlagsmessgeräten
Étalonnage et précision des pluviomètres sans captage
Ta slovenski standard je istoveten z: CEN/TR 17993:2023
ICS:
07.060 Geologija. Meteorologija. Geology. Meteorology.
Hidrologija Hydrology
17.120.20 Pretok v odprtih kanalih Flow in open channels
SIST-TP CEN/TR 17993:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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CEN/TR 17993
TECHNICAL REPORT

RAPPORT TECHNIQUE

October 2023
TECHNISCHER REPORT
ICS 07.060; 17.120.20
English Version

Calibration and accuracy of non-catching precipitation
measurement instruments
Étalonnage et précision des pluviomètres sans captage Kalibrierung und Genauigkeit von nicht auffangenden
Niederschlagsmessgeräten


This Technical Report was approved by CEN on 8 October 2023. It has been drawn up by the Technical Committee CEN/TC 318.

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, Türkiye 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
© 2023 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TR 17993:2023 E
worldwide for CEN national Members.

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CEN/TR 17993:2023 (E)

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Main characteristics of atmospheric precipitation . 6
4.1 Definitions . 6
4.2 Particle size distribution . 7
4.3 Shape of the rain drop . 9
4.4 Terminal fall velocity . 10
5 Non-catching precipitation measurement instruments . 12
5.1 General. 12
5.2 Optical gauges . 12
5.2.1 General. 12
5.2.2 Optical transmission . 12
5.2.3 Optical scattering . 13
5.2.4 Optical imaging . 13
5.3 Impact disdrometers . 14
5.3.1 General.
...