Data Visualization of Temperature Field in Environmental Test Equipment

A novel design of a temperature test chamber in multi-parameter combined environmental test was introduced, in which thermoelectric coolers were adopted to achieve both high and low temperature. Multiple distributed actuators and temperature sensors were used for improving the evenness of the temperature field. A well performed cooling system for waste heat dissipating was designed based on air-cooled radiator and circulating water flow. A temperature control system based on PC and MCU with wireless communication modules was designed. The thermoelectric cooler was driving by H-bridge circuit, whose power was controlled by PWM signal. PID algorithm was applied and average temperature was adopted to be the controlled variable. Measurement and control software on the PC and MCU was analyzed and its flow diagram was given. Influenced by centrifugal acceleration, unevenness of the temperature field would increase. A fan was mounted at the bottom of the chamber to improve the evenness of the temperature field. The experiment results show that the temperature environment with other combined environment is realized in the test chamber based on the above technology.

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Characteristics and Application of Temperature-Field Emitters

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100114347 ◽

1975 ◽

Vol 33 ◽

pp. 144-145

Author(s):

N. Tamura ◽

T. Goto ◽

Y. Harada

Keyword(s):

Temperature Field ◽

Electron Microscope ◽

Field Emission ◽

Resolving Power ◽

High Brightness ◽

Field Emitters ◽

Emission Electron ◽

Sufficient Stability ◽

Scanning Electron ◽

Illuminating System

On account of its high brightness, the field emission electron source has the advantage that it provides the conventional electron microscope with highly coherent illuminating system and that it directly improves the, resolving power of the scanning electron microscope. The present authors have reported some results obtained with a 100 kV field emission electron microscope.It has been proven, furthermore, that the tungsten emitter as a temperature field emission source can be utilized with a sufficient stability under a modest vacuum of 10-8 ~ 10-9 Torr. The present paper is concerned with an extension of our study on the characteristics of the temperature field emitters.

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Multiple-fracturing and viewing of the same frozen sample at different depths using a low temperature FESEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100166567 ◽

1996 ◽

Vol 54 ◽

pp. 820-821

Author(s):

M.V. Parthasarathy ◽

C. Daugherty

Keyword(s):

Temperature Field ◽

Low Temperature ◽

Field Emission ◽

Multiple Fracture ◽

Precise Control ◽

Cold Stage ◽

Different Depths ◽

Transfer Device

The versatility of Low Temperature Field Emission SEM (LTFESEM) for viewing frozen-hydrated biological specimens, and the high resolutions that can be obtained with such instruments have been well documented. Studies done with LTFESEM have been usually limited to the viewing of small organisms, organs, cells, and organelles, or viewing such specimens after fracturing them.We use a Hitachi 4500 FESEM equipped with a recently developed BAL-TEC SCE 020 cryopreparation/transfer device for our LTFESEM studies. The SCE 020 is similar in design to the older SCU 020 except that instead of having a dedicated stage, the SCE 020 has a detachable cold stage that mounts on to the FESEM stage when needed. Since the SCE 020 has a precisely controlled lock manipulator for transferring the specimen table from the cryopreparation chamber to the cold stage in the FESEM, and also has a motor driven microtome for precise control of specimen fracture, we have explored the feasibility of using the LTFESEM for multiple-fracture studies of the same sample.

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