RF and Laser trivia

Question 1

Which government agency regulates the classification and control measures Incorporated into laser products? Rev.1

Answer 1

FDA

Question 2

Conjunctivitis may result from a welding arc due to:Rev.1

Answer 2

UV radiation. The wavelengths responsible for conjunctivitis are 270-280 nm in the UV area of the electromagnetic spectrum.

Question 3

The most important type of UV for causing cancer from sunlight is: Rev.1

Answer 3

UVB

Question 4

Most biologically effective wavelength for killing microbes by UV. Rev.1

Answer 4

270 nm UVB

Question 5

Eye exposure to a 1520 to 1570 nm laser results in damage to: Rev. 1

Answer 5

The Cornea. Wavelengths greater than 1400 nm are absorbed in the cornea

Question 6

Laser wavelengths generally considered retina hazards Rev. 1

Answer 6

400 to 1400 nm

Question 7

What is the usual unit for measurement of laser radiationRev.1

Answer 7

J/cm^2 or W/cm^2

Question 8

Target organ for consideration of biological damage to humans from laser exposure is the Rev. 1

Answer 8

Eye. Skin is a close second.

Question 9

Far infrared wavelengthRev. 1

Answer 9

1400nm to 1mm

Question 10

Near Infrared wavelengthRev. 1

Answer 10

780 to 1400 nm

Question 11

Visible electromagnetic spectrumRev. 1

Answer 11

400nm to 780nm

Question 12

Ultraviolet electromagnetic spectrumRev. 1

Answer 12

Far: 200-315nm Near: 315-400 nm

Question 13

Three areas of eye sensitivityRev. 1

Answer 13

Retina, Lens, Cornea

Question 14

Wavelengths that put the retina at riskRev. 1

Answer 14

Visible, IR-A (near)

Question 15

Wavelengths that put the lens at riskRev. 1

Answer 15

UV-A

Question 16

Wavelengths that put the cornea at riskRev. 1

Answer 16

UV-B, UV-C, IR-B, IR-C

Question 17

Class 1 laserRev. 1

Answer 17

Laser cannot cause injury either because it is too low powered or because of engineered safety controls.

Question 18

Class 2 laserRev. 1

Answer 18

May be viewed for less than 0.25 seconds. The aversion response, which leads to a blink in less than 0.25 second, is sufficient to prevent injury to the eye. Max power level = 1 mW

Question 19

Class 3a laserRev. 1

Answer 19

Can injure the eye in intrabeam viewing for less than 0.25 seconds ,or viewing a specular reflection for less than 0.25 seconds. Max power level = 5 mW.

Question 20

Class 3b laserRev. 1

Answer 20

Same as 3a, except max power level = 500 mW, max radiant exposure = 10 j/cm^2 per pulse. ANSI ‘DANGER’ Sign.

Question 21

Class 4 laserRev. 1

Answer 21

Hazardous to the eyes and the skin during intrabeam and diffuse exposure. Potential fire hazard. Power level >500 mW. ANSI ‘DANGER’ sign

Question 22

Aversion response time for visible lightRev. 1

Answer 22

0.25 seconds

Question 23

Aversion response time for IRRev. 1

Answer 23

10 seconds

Question 24

one Watt is equal toRev. 1

Answer 24

1 joule per second

Question 25

Peak Power (Watts)Rev. 1

Answer 25

Energy/Time (Joules/second)

Question 26

Irradiance (E)Rev. 1

Answer 26

E=Watts/((pi/4)(cm)^2))

Question 27

Radiant exposure (H)Rev. 1

Answer 27

H=Joules/((pi/4)(cm^2))

Question 28

Optical DensityRev. 1

Answer 28

OD=Log((E or H/MPE))