Plancks Constant Apparatus

The Apparatus consist of the following :1. Photo Sensitive Device : Vacuum phototube.2. Light source   : Halogen tungstenlamp 12V/35W3. Colour Filters  :635mm. 570nm, 540nm,500nm 460nm.4. Accelerating Voltage  :Regulated VoltagePower SupplyOutput :±15V continuously variable throughmulti-turn potDisplay   :3½ digit 7-segment LEDAccuracy  : +0.2%5. Current Detecting Unit : DigitalNanoammeterIt is high stability low current measuringinstrumentRange       : 1000 μA, 100 μA, 10 μA & 1μA with 100% over ranging facilityResolution : 1nA at 1μA rangeDisplay     : 3½ digit 7-segment LEDAccuracy : +00.2%6. Power Requirement      : 220V + 10%,50Hz or 110V + 10%, 60Hz as required.7. Optical Bench  :The light source can bemoved along it to adjust distance between thelight source and the phototube, scale length is400mm. A tube is provided to install colourfilter and a focus lens is fixed in the backend.The set-up is complete in all respect, noadditional accessory required.