5 Fundamentals of Sensors – Review Questions

(PC: “Hand holding magnifying glass among a lot of questions. Finding answers to questions and solving problems” by wuestenigel is licensed under CC BY 2.0.)

Questions to review:

1. Short Answer: Explain the difference between a potentiometer sensor and an optical rotary encoder. In what types of automation applications might you use each sensor?

2. Multiple Choice: A slotted optical coupler is a type of proximity sensor. How does this sensor detect the presence or absence of an object? a) By measuring a change in voltage across a resistor. b) By detecting a change in magnetic field. c) By interrupting a light beam. d) By measuring the force exerted on the sensor.

3. Challenge Question: Imagine you are designing an automated watering system for plants. What sensor(s) would you use and why? Explain your reasoning.

4. True or False: All sensors convert the physical quantity they measure into an electrical signal.

5. Application Problem: A robotic arm needs to precisely measure the angle of its elbow joint. Which type of sensor (potentiometer, encoder, LVDT) would be most suitable, and why?

6. Open-ended: Discuss the advantages and disadvantages of using strain gauge sensors compared to pressure sensors for measuring force in an automated system.

7. Matching: Match the following sensor types with their corresponding applications:

a) Temperature sensor 
b) Flow sensor
c) Vision sensor
d) Load sensor

i) Monitoring liquid level in a tank
ii) Detecting the presence of a moving object
iii) Measuring air temperature in a greenhouse
iv)  Verifying the weight of a package on a conveyor belt 

8. Design Challenge: You are tasked with designing a security system for a home. Briefly describe two different sensor types you would use and how they would function within the security system.

9. Think-Like-an-Engineer: Hall effect sensors are commonly used in proximity sensing applications. Explain the scientific principle behind the Hall effect and how it is utilized in these sensors.

10. Research and Report: Choose a specific sensor technology introduced in this module (e.g., ultrasonic sensor, LVDT) and research its real-world applications beyond industrial automation. Prepare a short report summarizing your findings.