PASCO TD-8555 THERMAL RADIATION SYSTEM - Manual (Page 18)

14
Thermal Radiation System 012-04695D
Procedure
ä IMPORTANT: The voltage into the lamp should NEVER exceed 13 V. Higher voltages
will burn out the filament.
① BEFORE TURNING ON THE LAMP, measure T
ref
, the room temperature in degrees
Kelvin, (K=°C + 273) and R
ref
, the resistance of the filament of the Stefan-Boltzmann Lamp
at room temperature. Enter your results in the spaces on the following page.
② Set up the equipment as shown in Figure 3.1. The voltmeter should be connected directly to
the binding posts of the Stefan-Boltzmann Lamp. The Sensor should be at the same height as
the filament, with the front face of the Sensor approximately 6 cm away from the filament.
The entrance angle of the thermopile should include no close objects other than the lamp.
③ Turn on the power supply. Set the voltage, V, to each of the settings listed in Table 3.1 on
the following page. At each voltage setting, record I, the ammeter reading, and Rad, the
reading on the millivoltmeter.
ä IMPORTANT: Make each Sensor reading quickly. Between readings, place both sheets
of insulating foam between the lamp and the Sensor, with the silvered surface facing the
lamp, so that the temperature of the Sensor stays relatively constant.