Self-Test A-4.2 Temperature Measuring Instruments

Complete Self-Test A-4.2 and check your answers.

1. Liquid glass thermometers with longer stem lengths will give more accurate readings
   1. True
   2. False

    

2. The red-coloured fluid found in some glass-stem thermometers is mercury.
   1. True
   2. False

    

3. What type of sensing elements do dial stem thermometers use?
   1. Mercury bulb
   2. Bimetallic element
   3. Gas-filled sensing bulb
   4. Thermistor

    

4. What is the advantage of mounting a thermometer probe in a thermowell?
   1. Electrically grounds the sensor
   2. Increases the accuracy to the sensor
   3. Slows the sensor response to process temperature change
   4. Can easily change the thermometer/sensor without draining the piping or vessel

    

5. Dial thermometers have better accuracy and larger temperature range than digital thermometers.
   1. True
   2. False

    

6. RTDs and thermistors are both which type of sensor?
   1. Bimetallic coil sensors
   2. Capillary tube sensors
   3. Variable millivolts sensors
   4. Variable resistance sensor

    

7. What statement best describes a negative-coefficient thermistor (NTC)?
   1. Resistance increases as temperature rises.
   2. Resistance decreases as temperature rises.
   3. As temperature rises, an increased millivolt signal is created.
   4. As temperature rises, the amount of thermal radiation emitted increases.

    

8. What statement best describes a thermocouple?
   1. Resistance increases as temperature rises.
   2. Resistance decreases as temperature rises
   3. As temperature rises, an increased millivolt signal is created.
   4. As temperature rises, the amount of thermal radiation emitted increases.

    

9. What does the most common type of hand-held non-contact thermometer detect?
   1. Gamma rays
   2. Microwaves
   3. Infrared energy
   4. Ultraviolet energy

    

10. Because the intensity of the light lasers used for heat guns is low, it is OK to stare at the beam.
    1. True
    2. False

     

11. When using an IR thermometer with a 10:1 D:S, if the size of the target is about 12 in. in diameter, what is the maximum distance the measurement should be taken from?
    1. 0.83 ft
    2. 1.2 ft
    3. 10 ft
    4. 12 ft

     

Answer Key: Self-Test A-4.2 is on the next page.