ME Chapter 2

Which of the following criteria can be used to classify sensors?

• Signal source

• Measurand

• Measuring volume

• Measuring duration

• Measuring principle

Which of the following statements is true for active sensors?

• They add energy to the measurement process.

• An external energy source provides the necessary energy

• They produce energy from the measurment process

• They record the measurand by means of physical/chemical effects

Which sensor is a passive sensor?

• Strain gauge

• Hot wire

• Thermocouple

• Capacitive pressure sensor

• Photo element

Thermocouples are based on which following effect?

• Seebeck effect

• Joule-Thomson effect

• Carnot effect

• Kirchhoff effect

• Skin effect

What sensor is displayed in the shown image?

• Strain gauge

• Load-cell

• Extensometer

• Capacitive pressure sensor

• Linear variable differential transformer (LVDT)

Matthiessen's law contains which of the following statements regarding the specific electrical resistance of a material?

• Volume-dependency due to the size of the measured material

• Temperature-independency due to scattering of electrons by defects

• Electric current-dependency due to the amount of electrons passing through the material

• Temperature-dependency due to scattering of electrons by lattice vibrations

Ultrasonic waves are part of which frequency range?

• 5 - 10 kHz

• Above 20 kHz

• Below 13 kHz

• 10 - 20 MHz

• 5 - 30 Hz

What types of measurement principles can be used to investigate the volume of a material?

• Ultrasonic measurement

• Infrared thermography

• X-ray radiation

• Optical-deformation measurement