Hitachi S-4800 manual Evacuation System, Protection Devices

(6)	Signal processing modes	Automatic brightness control,
		Gamma control,
		Automatic focus,
		Automatic stigmator
(7)	Automatic data display	Image number, accelerating voltage, magnification,
		micron bar, micron value, date/time and working
		distance can be printed on the film.
(8)	Data entry	Alphanumeric characters, numbers, and marks can
		be written on the image from the keyboard.
(9)	Electrical image shift	±12 µm (WD = 8 mm)

6.Evacuation System

(1)	System type	Fully automatic pneumatic-valve system
(2)	Ultimate vacuum levels	Specimen chamber :	7 × 10-4Pa
		Electron gun chamber :

IP-1	1 ×	10-7	Pa or better
IP-2	2 ×	10-6	Pa or better
IP-3	7 ×	10-5	Pa or better

(3)	Vacuum pumps	Electron optical system :		3 ion pumps
		Specimen chamber	:	Turbo molecular pump
		1 oil rotary pump should be provided by user.
(4)	Compressor	Oil-less type compressor should be provided by user.

7.Protection Devices

Warning devices	Power failure, Cooling-water interruption, Inadequate
	vacuum

PRECAUTION - 10