Electron microscopy
 
Vacuum Systems, Gauges, and Applications
- Practical Electron Microscopy and Database -
- An Online Book -
Microanalysis | EM Book                                                                                   http://www.globalsino.com/EM/        

This book (Practical Electron Microscopy and Database) is a reference for TEM and SEM students, operators, engineers, technicians, managers, and researchers.
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In general, the vacuum systems of standard EMs are composed of mechanical pump(s) (rotary pumps, rough pumps, or forepumps), diffusion pump(s), vacuum gauges, switching valves, and a network of connecting pipes.

Table 2351. Typical working pressure ranges and accuracies of various vacuum gauges.

Ultra-high vacuum
(<10-7 mbar or <10-5 Pa)
High vacuum
(10-7-10-3 mbar or 10-5-10-1 Pa)
Medium vacuum
(10-3 - 1 mbar or 10-1 - 101 Pa)
Rough vacuum
(1-103 mbar or 101-105 Pa)
Accuracy
10-13 mbar 10-11 mbar 10-9 mbar 10-8 mbar 10-7 mbar 10-6 mbar 10-5 mbar 10-4 mbar 10-3 mbar 10-2 mbar 10-1 mbar 1 mbar 102 mbar  
Gauges
                      Active strain gauge
 
                Active thermocouple gauge        
           
Liquid level manometer
 
         
Capacitance diaphragm (CDG)
        ±0.02 to 0.2%
             
Elastic element gauge
 
         
Compression gauge
 
               
Pressure balance
 
         
Viscosity gauge (spinning rotor)
      ±1 to 10%
                  Thermal conductivity gauge (Pirani) ±5%
         
Thermomolecular gauge
       
             
Radioactive ionization gauge
 
         
Penning gauge
       
   
Cold-cathode magnetron gauge
       
Cold-cathode inverted magnetron gauge
       
               
High-frequency vacuum test
 
           
Hot-cathode ionization gauge (HCIG)
      ±1%
         
High-pressure ionization gauge
 
         
Bayard-alpert gauge
           
   
Modulator gauge
           
Suppressor gauge
           
   
Extractor gauge
           
Bent beam gauge
           
Hot-cathode magnetron gauge
           
 
Pressure ranges
                   
Piston pump
 
                   
Diaphram pump
 
                   
Liquid-ring pump
 
             
Sliding vane rotary pump
 
                   
Multiple-vane rotary pump
 
               
Rotary piston pump
 
         
Rotary plunger pump
 
       
Roots pump
 
                   
Turbine pump
 
                   
Gaseous-ring pump
 
Turbomolecular pump
             
                   
Liquid jet pump
 
             
Vapor jet pump
 
 
Diffusion pump
         
   
Diffusion ejector pump
 
   
Absorption pump
 
 
Sublimation pump
             
Sputter-ion pump
             
Cryopump
               
 
Applications
 
Vacuum deposition/evaporation (a type of PVD processes)
             
 
   
       
PECVD
   
 
Gun
in TEMs
   
Specimen
chamber in TEMs
TEM chamber & camera
             
     
SEM
             

 

 

 

 

 

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