Liquid level detection in standard capacity measures with machine vision

Bobovnik, Gregor (author), Mušič, Tim (author), Kutin, Jože (author)

Capacity measures are commonly used volume standards for testing measuring systems for liquids other than water. Manual readings from the measuring scale can often be difficult due to the location of the capacity measure or to the nature of the measured liquid. This article focuses on the automation of this procedure by using a single camera machine vision system. A camera positioned perpendicular to the transparent neck captures the image of the liquid meniscus and the measuring scale. The volume reading is determined with the user-defined software in the LabVIEW programming environment, which carries out the image preprocessing, detection of the scale marks and the liquid level, correction of lens distortion and parallax effects and final unit conversions. The realized measuring system for liquid level detection in standard capacity measures is tested and validated by comparing the automated measurement results with those taken by the operators. The results confirm the appropriateness of the presented measuring system for the field of legal metrology.

• Language: English
• Keywords: liquid level, standard capacity measure, legal metrology, machine vision, parallax
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering
• Publication status: Published
• Publication version: Version of Record
• Year: 2021
• Number of pages: 13 str.
• Numbering: Vol. 21, iss. 8, art. 2676
• PID: 20.500.12556/RUL-135368
• UDC: 004.946:681.518.52:532(045)
• ISSN on article: 1424-8220
• DOI: 10.3390/s21082676
• COBISS.SI-ID: 59221251
• Publication date in RUL: 09.03.2022

Record is a part of a journal

• Title: Sensors
• Shortened title: Sensors
• Publisher: MDPI
• ISSN: 1424-8220
• COBISS.SI-ID: 10176278

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.
• Licensing start date: 10.04.2021

Secondary language

• Language: Slovenian
• Keywords: nivo kapljevine, etalonska posoda, zakonsko meroslovje, strojni vid, paralaksa