ISO 23435:2022

INTERNATIONAL ISO
STANDARD 23435
First edition
2022-04
Air quality — Test methods for snow
depth sensors
Qualité de l'air — Méthodes d'essai des capteurs de hauteur de neige
Reference number
© ISO 2022
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ii
Contents Page
Foreword .v
Introduction . vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Fundamentals of snow depth sensors . 2
4.1 Overview . 2
4.2 Observation methods . 2
4.3 Points to note . 2
5 Test criteria and summary of methods . 2
5.1 Test criteria and considerations . 2
5.1.1 Measurement performance . 2
5.1.2 Installation-related . 3
5.1.3 Environmental/operational . 3
5.2 Summary of test methods. 3
6 Manufacturer design specifications check . 4
6.1 Purpose . 4
6.2 Requirements to list . 4
7 Basic functional test .4
7.1 Purpose . 4
7.2 Calibration of the sensor prior to testing. 4
7.2.1 Calibration using a reference object . 4
7.2.2 Calibration by moving the target surface . 5
7.2.3 Plumb procedure (only applicable to sensors using visible laser signals) . 6
7.3 Basic functional test procedure . 7
7.3.1 Test setup . 7
7.3.2 Running test . 7
7.3.3 Evaluation of the results . 8
7.3.4 Consideration . 8
8 Temperature chamber test (optional) . 8
8.1 Purpose . 8
8.2 Test chamber . 8
8.3 Procedure . 8
8.4 Evaluation . 9
9 Calibration (ground level adjust) test . 9
9.1 Purpose . 9
9.2 Procedures . 9
10 Field tests . 9
10.1 Purpose . 9
10.2 Duration . 9
10.3 Siting . 10
10.4 Climate . 10
10.5 Installation . 11
10.5.1 Mounting and installation of ultrasonic snow depth sensors . 11
10.5.2 Mounting and installation of laser-based sensors . 11
10.6 Field site equipment . .12
10.6.1 Target surface (snow plate) .12
10.6.2 Reference measurements for comparison .12
10.6.3 Auxiliary environmental sensors . 13
10.7 Evaluation . 13
iii
10.7.1 Malfunctions . 13
10.7.2 Automatic quality control . 13
10.7.3 Evaluation of differences to reference . 13
10.7.4 Errors caused by field inhomogeneity or other unexpected conditions .13
Bibliography .14
iv
Foreword
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v
Introduction
Solid precipitation is one of the more complex parameters to be observed and measured by automatic
sensors. The measurement of precipitation has been the subject of a multitude of studies, but there has
been limited information regarding the procedures and performance criteria describing the ability and
[13]
reliability of automatic sensors to accurately measure solid precipitation .
Recently, an increasing percentage of precipitation data used in a variety of applications have been
obtained using automatic instruments and stations including the measurement of snow depth, and many
[13]
new applications have emerged .Also, the modern data processing capabilities, data management,
and data assimilation techniques provide the means for better assessment and error analysis.
For the past years, various automatic snow depth measurement systems or snow depth sensors
have been deployed and tested at different places to tak
...