Laboratory Equipments #3737091

We Offer Dependence of Hall Coefficient On Temperature Usefull for Physics and Material Science Lab. the Hall Voltage for P-carriers Has Opposite Sign from that for N-carriers. Therefore if a Semiconductor with P-type Doping is Gradually Heated Up, More and More Electrons from Its Valence Band Will Go to Conduction Band. as a Result Hall Voltage Would Fall Rapidly with Temperature and Even Become Zero or Change Sign. At the Point of Zero Hall Coefficient, It is Possible to Determine the Ratio of Mobilities B=micro(e)/ Micro(h). the Hall Coefficient Inversion is a Characteristic of Only P-type Semiconductors. the Set-up Consists of the Following: 1. Hall Probe (ge: P-type), Hpp-22 ge Single Crystal with Four Spring Type Pressure Contacts is Mounted On a Glass-epoxy Strip. Leads are Provided for Connections with the Current Source and Hall Voltage Measuring Devices. oven it is a Small Oven Which Could Be Easily Mounted Over the Crystal or Removed if Required. temperature Sensor cromel-alumel Thermocouple with Its Junction At a Distance of 1mm from the Crystal. 2. Hall Effect Set-up :dhe-22 the Set-up, Dhe-22 Consists of Two Sub Set-ups, Each Consisting of Further Two Units. measurement of Probe Current & Hall Voltage this Unit Consists of Digital Millivoltmeter and Constant Current Power Supply. the Hall Voltage and Probe Current Can Be Read On the Same Digital Panel Meter Through a Selector Switch. (a) Digital Millivoltmeter Specifications Range: 0-200mv (100v Min.) Accuracy: +-0.1% of Reading +-1 Digit Impedance: 1m Ohm (b) Constant Current Power Supply Specifications Current: 0-20ma (10 Micro Ampere Min) Accuracy: +-0.2% of the Reading or +-1 Digit Load Regulated: 0.05% for 0 to Full Load Line Regulation: 0.05% for 10% Variation measurement of Thermo Emf and Heater Current the Unit Consists of a Digital Millivoltmeter and Constant Current Power Supply. the Thermo Emf of Thermocouple and Heater Current Can Be Read On the Same Dpm Through a Selector Switch. (a) Digital Millivoltmeter Specifications : Range: 0-20mv Resolution: 10 Micro Volt Equivalent to 0.25c in Terms of Thermo Emf Accuracy: +-0.1% of Reading 1 Digit (b) Constant Current Power Supply Specifications Current: 0-1a Accuracy: +-0.2% of the Reading +-1 Digit Line Regulation: 0.1% for 10% Variation Load Regulated: 0.1% for 0 to Full Load 5. Electromagnet, Emu-50v 6. Constant Current Power Supply, Dps-50 7. Digital Gaussmeter, Dgm-202/ Dgm-102 the Experiment is Complete in all Respect.

We offer this instruments in two parts viz. PID Controlled electronics and a small oven. The oven has been designed for fast heating and cooling rates which enhances the effectiveness of controller. Heater is wound over a brass are side closed brass cylinder and no insolation is provided between the heater and ambient, which enhances its rate of heating and cooling. The temperature is sensed by RTD (A class). The basic design of the controller is around the PID configuration for its obvious advantage, wastage of power is avoided by using a pulse width modulation (PWM) switch. This combination has the advantage of both ON-OFF controller and a linear PID Controller. Teh result is a good stable and accurate temperature control. Specifications of the Oven Temperature Range: Ambient to 200C Stability: Short Range: +-0.2C Long Range: +-0.5C Measurement Accuracy: +-0.5C (typical) Oven Dimensions: Heating Chamber inner Diameter: 25mm, Height: 100mm Sensor: RTD (A class) Display: 3.5 digit, 7 segment LED (12.5mm)

We offer Study of Hybrid Parameters of A Transistor, the following studies can be carried out with this set-up: Study of h(11) parameter (input impendance parameter). Study of h(22) parameter (output admittance parameter). Study of h(21) parameter (forward current transfer ratio). Study of h(12) parameter (reverse voltage feedback ratio). The experimental set-up is provided with a built-in power supplied and is complete. The set-up is so designed that no high voltage is exposed and hence safe in handling by the students.

We offer Thermoluminescence of F-centres, in this Pure alkali halide crystals are transparent throughout the visible region of the spectrum. The crystals may be colored in a number of ways (1) by the introduction of chemical impurities (2) by introducing an excess of the metal ion (3) by X-ray, -ray, neutron and electron bombardment (4) by electrolysis Colour centres produced by irradiation with X-rays When a X-ray quantum passes through an ionic crystal, it will usually give rise to a fast photo-electron with an energy of the same order as that of the incident quantum. Such electrons, because of their small mass, do not have sufficient momentum to displace ions and therefore loose their energy in producing free electrons, holes, excitons and phonons. Evidently these while moving near the vacancies form trapped electrons as well as trapped holes. The trapped-electron or trapped-hole centres so formed can be destroyed (bleached) by illuminating the crystal with light of the appropriate wavelength or warming it. The experiment consists of the following Experimental set-up for creating thermoluminescence (1) Sample: KBr or KCl single crystal (2) Thermolumniscence Temperature Meter, TL-02 Digital Thermometer Oven Power Supply (3) Sample Holder (4) Thermoluniscence Oven (0-423K) (5) Black Box For measurement of luminescence intensity (1) Photomultiplier tube: 931A (2) PMT Housing with biasing circuit and coaxial cables etc. (3) High Voltage Power Supply, Model: EHT-11 Output : 0-1500V variable (1mA max.) Regulation : 0.05% Display: 3.5 digit 7-segment LED (4) Nanoammeter, Model DNM-121 Range: 100nA to 100mA full scale in 4 ranges Accuracy : 0.2%. Display: 3.5 digit 7-segment LED Complete in all respect, only X-ray facilities are required to create F-centers in the crystal.