This item can only be shipped to schools, museums and science centers
Study the photoelectric emission from a mixed metal (Cs/Sb) vacuum tube using this device. The vacuum phototube is contained within a light-tight box, along with a current-controlled incandescent lamp mounted on a slide, to explore the effect of light intensity according to the inverse square law. The lamp is operated from outside the box to vary the illumination of the phototube. The control and measurement unit contains an adjustable highly stabilized lamp power supply. Current is indicated on a three-digit display. The apparatus shows the linear relationship between light intensity and emission current and provides the characteristic curves of a vacuum photocell.
• Phototube: GD-51 Mixed metal vacuum tube, rated voltage 24 V • Lamp: Incandescent lamp, 12 V/5 W • Lamp Supply: 185 mA, display resolution: 1 mA • Electrode voltage supply: –25.5 ±23.5 V, display resolution: 0.1 V • Photocurrent amplifier ranges: 0–19.99 µA; 0–199.99 µA x 0.1 µA • Light-tight box, slide range: 0.5–40.0 cm, mm scale