# Geometrical Parametric Study on Steel Beams Exposed to Solar Radiation
## 3 The Experimental Steel Beam  
Figure 3 illustrates the sectional and longitudinal dimensions of the steel beam used in this research. As shown, the beam was made from 8 mm thickness steel plates to form an I-shape with 200 mm width flanges and a depth of 500 mm. After instrumentation, the beam was installed in an open field where shadings from all buildings around the field were calculated and found ineffective. A compact weather station composed of three sensors was installed beside the beam as shown in Figure 4a. The first sensor was a temperature probe to measure the shade air temperature (covered by a solar shield), the second was a pyranometer to measure the total solar radiation received by a horizontal surface, while the third was a three-cup anemometer to measure the speed of the wind in the field. The three environmental sensors were provided by Campbell Scientific (Logan, UT, USA) to assure their compatibility of the used data acquisition system that uses a Campbell CR1000 system as the core data logger. The 108-air temperature probe use a thermistor that can accurately measure a temperature range of \(-\)5 to +95 \({}^{\circ}\)C with an error of approximately \(\pm\)0.2 to \(\pm\)0.3 \({}^{\circ}\)C. The dome-shaped CS300 silicon type pyranometer was the adopted solar radiation sensor. This sensor can measure a high range of global Sun plus sky radiation  
Figure 2: Effect of flange width on web shadowing.  
reaching 2000 W/m\({}^{2}\) with a maximum error of 5%. The three-cup NRG#40 anemometers from NRG system will be used to measure wind speed as shown in Figure 4a. This type of device recommended by Campbell Scientific. The sensor is able to read the wind speed ranging from 0 to 96 m/s (0 to 215 mph). The NRG#40 was the three conical-cups wind sensor used. It measures wind speeds up to 10 m/s with an estimated error of \(\pm\)0.14 m/s. The three sensors are clearly visible next to the steel beam in Figure 4a.  
To study the distribution of temperatures in the steel beam, seven type-T thermocouples were installed on the top flange, bottom flange and the northern surface of the web as shown in Figure 4b. The thermocouples are made of copper and constant, have a measurement range of \(-\)200 to 370 \({}^{\circ}\)C with an accuracy of \(\pm\)0.5 \({}^{\circ}\)C. Two thermocouples were installed on the top surface (TS) and bottom surface (BS) of the beam, while two thermocouples (TF and BF) were installed on the opposite surfaces of the top and bottom flanges. The rest three thermocouples were installed along the vertical centerline of the beam's web, which are W1, W2 and W3. The locations of these thermocouples are shown in Figure 4b, while their exact coordinates are listed in Table 1. The coordinates were calculated considering the origin (0, 0) is located at the bottom surface of the bottom flange  
Figure 4: The experimental steel beam: (**a**) Southern view and thermal loads sensors; (**b**) Northern view and thermocouple locations.  
Figure 3: The steel beam dimensions: (**a**) Section; (**b**) Side view.  
along the vertical centerline of the web, while all thermocouples were installed at the mid-span section.