Card Set Information

2014-05-12 08:24:02
unit medical physics
Science unit 8
How different thermometers work.
Show Answers:

  1. How does a liquid in glass thermometer work?
    firstly, the heat causes the liquid to expand. As it begins to expand it rises up the tube.

    This process occurs through conduction.
  2. What are the advantages of a liquid in glass thermometer?
    • - portable
    • - cheap
    • - does not require batteries
    • - easy to clean
    • - does not require medical training
  3. What are the disadvantages of liquid in glass thermometers?
    • - it could break and cause damage to the patient.
    • - it's not very precise
    • - human error (can be misread easily)
  4. How does a thermistor work?
    • For thermistors to work a resistance is needed in an electrical circuit for the temperature to take affect.
    • As the temperature increases the resistance decreases.
    • The greater the change in temperature the greater the change in resistance.
    • the digital reading for the temperature is then calibrated against the resistance.
  5. What are the advantages of electrical thermometers?
    • More accuracy (less chance of human error)
    • Readings appear automatically
    • readings can be stored
    • more sensitive so it can sense a slight change in temperature.
  6. What are the disadvantages of electrical thermometers?
    • can run out of batteries
    • too sensitive and external surroundings can affect the temperature measured.
    • non invasive
  7. How does a forehead strip thermometer work?
    • it works through the process of conduction.
    • the strip changes colour dependant on the temperature of the patient.
  8. Advantages of a forehead strip thermometer?
    • - does not require batteries
    • - no medical training
    • - easy to read
  9. Disadvantages of forehead strip thermometers
    • - it's not very accurate
    • - readings cannot be taken automatically
    • - human error ( scale can be misread)