Mjerenje temperature u hladnomorskim spiljama

undergraduate thesis

• Title (english): Temperature measurements in sublittoral caves
• Author: Danijela Havoić
• Mentor: Lovorka Grgec Bermanec (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2018-02-28, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering

Abstract

Ovaj rad temelji se na ispitivanju mjernih uređaja (data loggera) koji se koriste za mjerenje temperature u hladnomorskim spiljama u temperaturnom rasponu od 0°C do 30°C. Također su obrađeni dobiveni podaci izmjereni u spilji Poganica na otoku Šolti u razdoblju od 2008. do 2012. godine. U prvom dijelu rada provedeno je umjeravanje data loggera u šest točaka: 0°C, 6°C, 12°C, 18°C, 24°C, 30°C iz čijih je rezultata kasnije izračunata mjerna nesigurnost. Pokazalo se da su odstupanja data loggera u svim točkama mala. Korišten je etalonski platinski otpornički termometar Pt 25,5, a umjeravanje je provedeno na Fakultetu strojarstva i brodogradnje čiji je Laboratorij za procesna mjerenja nositelj državnih etalona za temperaturu, tlak i vlažnost. Drugi se dio rada odnosi na obradu podataka izmjerenih u spilji s ciljem provjere jesu li uređaji, nakon određenog vremena u spilji, izgubili točnost. Zamišljeno je da se prati kašnjenje maksimuma temperatura unutar spilje za onim na samom ulazu u spilju, no ispostavilo se da je problem mnogo složeniji te nije moguće na ovaj način odrediti točnost uređaja. Naime, dolazi do prijenosa topline između toplije i hladnije vode u različitim dijelovima godina te se ne može odrediti shema primjenjiva u svim situacijama.

Abstract (english)

This paper is based on assessing measuring devices (data loggers) which are used for temperature measurements in sublittoral caves ranging from 0°C to 30°C. The collected data, measured in the cave Poganica on the island of Šolta between 2008 and 2012, are also processed. In the first part of the paper a calibration of data loggers in six points: 0°C, 6°C, 12°C, 18°C, 24°C, 30°C was carried out. From those results the measurement uncertainty was calculated. It turned out that the deviation of data loggers are small at all points. Standard platinum resistance thermometer Pt 25,5 is used. The calibration was carried out at the Faculty of Mechanical Engineering and Naval Architecture, whose Laboratory for Process Measurements is the holder of national standards for temperature, pressure and humidity. The second part of the paper refers to processing the data measured in the cave in order to check whether the devices had, after specific time in cave, lost their accuracy. It had been planned to track the delay of maximum temperature inside the cave from the one at the entrance to the cave. However, it turned out that the problem was much more complicated and it is not possible to determine the accuracy of the devices in this way. The heat transfer between warm and cold water occurs in different parts of the year and there is no way to determine a scheme that can be applied in all situations.

• Keywords: data loggeri; umjeravanje; mjerna nesigurnost; poganica
• Language: croatian
• URN:NBN: urn:nbn:hr:235:843389
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2019-05-22 21:43:56