Subsection 12 Electrostatic sensitive devices

Question 1

A flight deck CRT LRU is being replaced, What does ESDS label indicate?

Answer 1

Do not touch plug pins or leave them exposed

Question 2

A Humid atmosphere?

Answer 2

Reduces static charge

Question 3

A Wristband must be worn when working with ESDS devices to dissipate and prevent?

Answer 3

Static build up on the operator

Question 4

After attaching a wrist strap to your wrist ( which is connected to aircraft ground ) Prior to removal of the ESDS equipment the resistance measured between your skin and the pin ground must be?

Answer 4

greater than 1 Megaohms

Question 5

An electrostatic charge below 300v ?

Answer 5

May not be felt by most people

Question 6

An electrostatic charge may be built up between two objects due to the tribo-electric effect which causes?

Answer 6

A transfer of electrons

Question 7

Before fitting a printed circuit board you should check the resistance between skin and strap and plug is

Answer 7

More than 1 megaohms

Question 8

Before removing an assembly from an aircraft, with regards to HIRF you must first ensure there is ?

Answer 8

A minimum current flow between you and the assembly

Question 9

During an EFIS screen fit?

Answer 9

Do not touch the terminals

Question 10

Electrostatic discharge occurs when?

Answer 10

Materials of different potential are brought in close proximity of each other

Question 11

ESDS bags are sealed by?

Answer 11

Twine ( 100% cotton )

Question 12

Ideally static dischargers are sited on?

Answer 12

Any trailing edges

Question 13

In the triboelectric series the levels of charge are listed in respect to?

Answer 13

Cotton

Question 14

The resistance of the wrist strap used as part of the antistatic precautions should be ?

Answer 14

250 Kohms- 1.5 Mohms

Question 15

What precautions are required when removing ESDS equipment?

Answer 15

Wrist strap connected to an approved ground point

Question 16

When handling PCB’s labelled ESDS, what precautions are taken?

Answer 16

Isolate electrical power before installing on the aircraft.

Question 17

When removing a PC card from an ESDS assembly ensure a low current path between?

Answer 17

You and the aircraft

Question 18

Which of the following ESDS devices can withstand higher static electricity voltage?

Answer 18

SCR

Question 19

Which of the following is least sensitive to damage caused by static discharge?

Answer 19

Bi-Polar transistor

Question 20

With a relative humidity of 10-20% if you walked over a carpet what electrostatic voltage value would you expect to see?

Answer 20

35,000 volts