Equipment Used in the Seebeck Lab

Here you will find information for all of the equipment used in the Seebeck Lab.

Please note that there is a new procedure for using the Seebeck/cryostat equipment. Users need to log their time in a purple notebook (notebook is placed beside cryostat). Since no body wants to ruin another person's experiment, please log in and leave a note implying the system is in use. The details of the procedure can be found in the first page of the purple notebook.

The LabView program is used to gather data from the Seebeck apparatus. A full description of the user interface can be found here.

There are two versions of the Seebeck program located on the desktop. Version 8.0 uses the Keithley 195A to read the differential thermocouple voltage. Version 8.1 uses a Tektronix DM5120 to do this. You want to use 8.0 unless the 195A is not working. Version 8.2 automatically converts the differential thermocouple voltage to a temperature. Currently, it assumes RT (40 uV/K).

Here is a list of instruments that are fed to the computer via GPIB cables:

• Keithley 195A Digital Multimeter measures the differential thermocouple voltage between the two copper blocks using cromel and alumel wires that are in thermal contact with the hot and cold blocks, but electrically insulated from them. It tells us the potential gradient between the blocks which is then manually converted to temperature using a K-Type calibration curve. The original pdf file was taken from http://www.capem.buffalo.edu/lab-manuals/keith195A.pdf.

• Keithley 2400 Source Meter applies a current to the resistor in the hot block, effectively heating it to create a temperature gradient. The original pdf file was taken from http://physics.utsa.edu/solarlab/manuals/Keithley_SourceMeter/2400S-900-01_(J_Aug_2007)(User).pdf.

• Lakeshore DRC-91CA Temperature Controller uses a type K thermocouple to measure the temperature of the system. This thermocouple is connected to the cold block and is electrically insulated from it. The original pdf file was taken from www.lakeshore.com/pdf_files/Obsolete/DRC-91CA_Manual.pdf.

• Tektronix DM5120 Programmable Digital Multimeter measures the potential difference between the two blocks created by the sample. This potential difference is measured relative to the copper blocks and indium strips. The original pdf was taken from http://128.238.9.201/~kurt/manuals/manuals/Tektronix/TEK%20DM%205120_5520%20Instruction.pdf.

Here is a list of all of the equipment used in the cryogenic process.

• 10 Kelvin Closed Cycle Refrigerator System Model CCS-300T from Janis Research Co. provides the enclosure necessary for bringing the system down to extremely low temperatures.

• Haskris R075 Refrigerated Water Recirculating System circulates water through the compressor. The original pdf was taken from http://www.bidonequipment.info/h_library.html#HASKRIS.

• Model 320 Autotuning Temperature Controller

• Leybold-Haraeus RW 3 Compressor Cryo Pump (no documentation found) compresses helium through the system, effectively lowering the temperature.

• Varian Turbo V-70 mini pumping station (with SD40 Forepump) evacuates the Seebeck system to pressures down to about 7.8E^-7 Torr.