General rules 3 – Emerson Process Management ControlWave EFM 3808 User Manual
Page 297
3
ESDS Manual
S14006
4/15/92
Table 1
Typical Electrostatic Voltages
Electrostatic Voltages
Means of Static
10-20 Percent
65-90 Percent
Generation
Relative Humidity
Relative Humidity
Walking across carpet
35,000
1,500
Walking over vinyl floor
12,000
250
Worker at bench
6,000
100
Vinyl envelopes for work instructions
7,000
600
Poly bag picked up from bench
20,000
1,200
Work chair padded with poly foam
18,000
1,500
2.
General Rules
(1)
ESD-sensitive components shall only be removed from their static-shielding
bags by a person who is properly grounded.
(2)
When taken out of their static-shielding bags, ESD-sensitive components shall
never be placed over, or on, a surface which has not been properly grounded.
(3)
ESD-sensitive components shall be handled in such a way that the body does
not come in contact with the conductor paths and board components. Handle
ESD-sensitive components in such a way that they will not suffer damage from
physical abuse or from electric shock.
(4)
EPROMS/PROMS shall be kept in anti-static tubes until they are ready to use
and shall be removed only by a person who is properly grounded.
(5)
When inserting and removing EPROMS/PROMS from PC boards, use a chip
removal tool similar to the one shown in the figure following. Remember, all work
should be performed on a properly grounded surface by a properly-grounded
person.