Figure 8
The vertical axis is labeled “Temperature (degrees Celsius)” and ranges from 0 to 1200 in increments of 200. The horizontal axis is labeled “Time (minutes)” and ranges from 0 to 120 in increments of 20. The graph features four distinct colored lines, each representing a different temperature profile, and their labels are provided in a legend located in the center-right of the plot area. The red line represents “Upper limit” and generally shows the highest temperature profile. The black line represents “I S O 834” and serves as a reference standard, positioned below the ”Upper limit” and mostly superimposing the “Furnace” curve. The blue line represents “Furnace” and indicates the actual furnace temperature, generally following the I S O 834 curve but slightly below it at first. The orange line represents “Lower limit” and shows the lowest temperature profile, positioned below the “Furnace” curve. All four curves originate from approximately 0 degrees Celsius at time 0. They all exhibit a rapid initial increase in temperature, followed by a more gradual increase as time progresses. Note: All the numerical data values are estimated.Measured furnace temperature during the test. Authors’ own work