Technical gazette, Vol. 19 No. 3, 2012.
Original scientific paper
Statistical process control of fire-resistant coating production based on thickness measurements
Biserka Runje
orcid.org/0000-0002-7786-0864
; University of Zagreb, Faculty of Mechanical Ungineering and Naval Architecture, Ivana Lučića 5, 10000 Zagreb, Croatia
Srđan Medić
orcid.org/0009-0004-2255-0190
; Karlovac University of Applied Sciences, Trg J. J. Strossmayera 9, 47000 Karlovac, Croatia
Živko Kondić
; Varaždin University of Applied Sciences, J. Križanića 36, 42000 Varaždin, Croatia
Željko Alar
; University of Zagreb, Faculty of Mechanical Ungineering and Naval Architecture, Ivana Lučića 5, 10000 Zagreb, Croatia
Đuro Tunjić
; TÜV Croatia d.o.o., Member of TÜV NORD Group, Dr. Mile Budaka 42A, 35000 Slavonski Brod, Croatia
Abstract
This article focuses onto the process of fire-resistant coating production. That process belongs to the class of processes, considered statistically, which have only one, lower specification limit. Such processes are interesting in that they usually do not have the accompanied normal distribution. In order to bring the process under control, we monitored the fire-resistant coating production using the x-R control chart. The process capability analysis was applied on one set of data analyzed using three different methods. In the first method the data were approximated using the 3-parameter Weibull distribution. In the second method, data were transformed using the Johnson transformation while in the third method, applied for the purpose of comparison of sets, data were approximated with normal distribution. In the accompanied experiment, the thickness of the fire-resistance coating was measured on seven steel girders. The results have been analyzed using the trial version of the Minitab software package. Using the Monte Carlo method, numerical simulations were performed in order to estimate the uncertainty of measurements of coating thickness.
Keywords
fire-resistant coating; measurement uncertainty; non-normal data; SPC
Hrčak ID:
86733
URI
Publication date:
19.9.2012.
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