Title: Sensor Articles

Author: Andrea Martin

Disciplines: Chemistry (can be adapted to other disciplines)

Introduction

The objective of this module is for the students to read and take quizzes on articles that discuss sensors used to detect chemicals affecting the environment or human health. Topics such as the following might be tested:

1. Sensor design.
2. What does the sensor detect?
3. Why is the sensor important in environmental monitoring or for human health?
4. How was the sensor used to detect the chemical of interest; what was the experimental setup?
5. Identify advantages and/or disadvantages of the sensor.
6. How did the sensor actually detect the chemical of interest; i.e. what is the chemistry involved?

Associated Maine Learning Results

MLR M

Required Equipment

The only equipment required are the articles students must read.

Procedure

• Students are informed of important details they need to focus on to succeed on the sensor article quiz (see Introduction).
• Students are either 1. provided website addresses to access articles or 2. directed to articles held in the school library or 3. handed materials in class. Note: One article can be given to all students or students can choose one article from a group of sensor articles.
• Students are given about two (2) weeks to read the articles.
• Students take a quiz on the articles (see Sample Questions).

Expected Results

Students are expected to understand important details, as presented in the above Introduction.

Troubleshooting

N/A

Sample Questions

1. In the sensor journal article you read, what chemical is the sensor designed to detect? (2 points)
   
2. Give a physical description of the sensor (include how the sensor detects the chemical in Question 1). (5 points)
   
3. Why is the sensor important for environmental monitoring or for human health? (3 points)
   
4. Briefly describe how the current ion mobility spectrometers (IMS) detect bomb residue. Include information on how the sample is collected. (5 points)
   
5. The following feature can be both an advantage and a disadvantage; explain why: An IMS is very sensitive. (3 points)
   
6. Which mode, POSITIVE or NEGATIVE, would an airport IMS operate? (1 point)
   
7. Multiple Choice. What is the identifying characteristic in IMS? (1 point)
   a. Amount of time an ion travels down the detector tube.
   b. Amount of light each ion produces when combined with the dopant gas.
   c. Temperature that compounds desorb off of the swab.
   
8. Give a physical description of the CO sensor. Also, provide information on what is done experimentally to allow CO to react with the sensor. (5 points)
   
9. What are the symptoms one has if they are experiencing carbon monoxide (CO) poisoning? (1 point)
   
10. Give 2 producers of CO that were mentioned in the article you read. (1 point)
    
11. Why is a spectrophotometer required in the detection of CO with this sensor? (2 points)
    
12. True/False? Catalytic converters reduce CO emissions from cars. (1 point)
    
13. Why do we need O2 sensors in our cars? (2 points)
    
14. Give a physical description of the oxygen sensor that is used in today’s cars. (1 point)
    
15. Is the following feature an advantage or a disadvantage of the oxygen sensor: The oxygen sensor responds instantly to changes in oxygen. Explain why. (2 points)
    
16. Describe how an oxygen (O2) sensor of today works in the exhaust system of your car. (5 points)

Resources

www.sciam.com/news_directory.cfm (Scientific American Journal)
www.chemistrycoach.com/high.htm#science (From this website, under “Topics,” you can go to “Science Publications.”)

Note: The author used “environmental sensors,” “sensors” or something related to one of the environmental topics (e.g. “ozone sensors”) when searching for articles.

Science Daily and Scientific American proved to be good resources.