Hitachi Microscope & Magnifier S-4800 Manual De Usuario

SAFETY - 4

 
Baking the electron gun part is carried out about once per 6 months to keep high vacuum inside 
the part.    When baking, the surface of the gun housing and ion pumps reaches around 250 

°

C. 

The electron gun part is surrounded by a metal guard to prevent high temperature hazard caused 
by direct contact.    However, the temperature of the upper stage surface rises up to   
100 

°

C and the temperature of the side cover surface also rises up to 75 

°

C.  The maintenance 

work of baking should be carried out by personnel trained by the manufacturer. 
 

 

 
The operator should not touch the covers when the electron gun and ion pumps are heated up to 
about 250 

°

C in order to keep the electron gun in ultra high vacuum.    Touching these sections 

would result in burns. 

Note that the above heated parts are still hot even after stopping heating. Cooling down to close 
to room temperature needs about 6 hours.

   

 
The ion pumps are constructed with permanent magnets.    There is a fringing magnetic field of 
about 10 mT at the ion pump surface and about 1 mT at the outside of the ion pump cover. 
 

 

 

•

 

Any person who carries a pacemaker embedded is not allowed to approach the ion-pump. 

•

 

Do not bring near the ion pump wristwatches and magnetic cards that are susceptible to 
magnetic fields.