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Photoelectric Effect Apparatus

(ships from manufacturer, est arrival 11/15/22)


Advanced physics items are drop shipped. These products are built to order. Carolina does not hold stock. Please allow 90 days to receive your item from the time you place your order. This is the industry standard for this type of equipment.

Examine the photoemission of a mixed alkali photocathode in a vacuum as a function of the illumination and the extraction voltage applied. The apparatus is robust and the electronics are very stable. No trouble should be encountered in normal operation. Also, this unit features precise, stable illumination and bias control for excellent results. Shielded cables connect a lighttight box to the control and measurement unit that contains a highly stabilized lamp power supply adjusted by a multiturn potentiometer. Includes instructions with suggested activities and sample data. Recommended for advanced and college-level physics.

The photocurrent amplifier and display may be used to measure the suppression voltage of the phototube but are not in the range to accurately determine Planck's constant using color filters.

The detailed instruction manual contains background information and sample data.

Phototube: Type GD-51 mixed-metal vacuum tube (Cs/Sb), 7-pin base
Rated Voltage: 24 V
Integral Sensitivity (white light): 100 µA/Lm
Lamp: Incandescent, bayonet type, 12 V, 5 W rating
Control Unit: Lamp Supply: 0 to 15 V, 185 to 665 mA on 10-turn potentiometer
Display Resolution: 1 mA
Electrode Voltage Supply: –25.5 to +23.5 V on 10-turn potentiometer
Display Resolution: 0.1 V
Photocurrent Amplifier: Ranges: 20 µA: 0 to 19.99 µA x 0.01 µA
200 µA: 0 to 199.9 µA x 0.1 µA
Fuse: Miniature fuse, 5 x 20 mm, 250 V, 1.5 A
Dimensions: 35 x 26 x 12 cm
Weight: 4.5 kg (10 lb)
Lighttight Box: Slide: Range: 0.5 to 40.0 cm, mm scale
Dimensions: 60.5 x 12 x 15 cm
Weight: 3.8 kg (8.4 lb)
Connecting Cords: 2 lamp supply cords, 75 cm L, spade lug/banana plug connectors
2 shielded photocurrent cords, 75 cm L, BNC/banana plug connectors
1 power cord, 2 m L


What’s Included:
  • 1 Phototube, Cs/Sb
  • 1 Lamp, Incandescent
  • 1 Control Unit
  • 1 Lighttight Box
  • 2 Cords, Lamp Supply (spade lug/banana plug), 75 cm
  • 2 Cords, Shielded Photocurrent (BNC, banana plug), 75 cm
  • 1 Cord, Power, 2 m
  • 1 Instructions
  • expand to see full list
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