This manual describes the Planck’s Constant Measuring Apparatus (Model PC-101). It outlines the components such as the vacuum photo tube, halogen tungsten light source, color filter set, regulated voltage power supply, digital nanoammeter, and the optical bench with a 400 mm scale. Detailed specifications for voltage output, display, accuracy, and power requirements are included.
The document guides users through installation, adjustment of the phototube and light source, and step‑by‑step experimental procedures to measure Planck’s constant. Safety precautions, cleaning instructions, and typical observation tables are also provided.
| Light source | Halogen tungsten lamp 12V/35W |
|---|---|
| Output voltage | +15 V continuously variable |
| Display | 3‑digit 7‑segment LED |
| Accuracy | 40.2 % |
| Power requirement | 110 V ±10 %, 60 Hz |
| Optical bench length | 400 mm |
Place the phototube on its base so that the cathode plate faces the lens, then secure the cover.
Operate the instrument in a dry, cool indoor space, keep it dust‑ and moisture‑proof, avoid direct light on the phototube, and switch off power after use.
The apparatus uses a 12 V, 35 W halogen tungsten lamp as the light source.