You are a professor in the field of building fires in civil engineering please help me polish the following text to make it suitable for SCI journalsThermocouples have limitations in accurately measur

Thermocouples are commonly used to measure temperatures in building fires, but their ability to accurately capture the continuous temperature field of a tunnel is limited. In contrast, infrared thermography can effectively measure the continuous temperature field of the tunnel surface. In this study, the outer surface temperature of a tunnel was monitored using infrared thermography during a fire test, as shown in Fig. 12. It is important to note that the lens angle of the infrared thermography was narrow, and therefore, not all areas of the ceiling could be monitored.

Analysis of Fig. 12 reveals that at the 100-minute mark, the temperature in the cracked area of the ceiling (approximately one-third of the tunnel's cross-section) increased significantly, while the temperature in the uncracked area of the ceiling remained notably lower. This finding is consistent with the macroscopic test phenomenon of the outer surface of the tunnel, as shown in Fig. 5, where irregularly distributed cracks were observed, and boiling water vapor overflowed from the concrete cracks. The high temperature at the concrete cracks is believed to have resulted from water and vapor in the high-temperature areas of the concrete migrating to the surface through the cracks, subsequently heating the concrete at the cracks.

A frame-by-frame analysis of the infrared image, combined with macroscopic observations of concrete cracking during the fire test, enabled the identification of the distribution of the primary cracks on the outer surface of the immersed tunnel, as presented in Fig. 13. These findings highlight the potential of infrared thermography in accurately measuring the continuous temperature field of a tunnel surface during a fire test, and its ability to aid in the identification of crack distribution and associated phenomena