Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help . how does a clinical thermometre differs from a laboratory thermoeter?

  1. Aug 21, 2005 #1
    Help..plzz. how does a clinical thermometre differs from a laboratory thermoeter?

    hey. anyone could help me in listing ways in which clinical thermometer differs from laboratory thermometer? with explaination for each difference?

    thanx everyone for ur help.
  2. jcsd
  3. Aug 21, 2005 #2


    User Avatar
    Staff Emeritus
    Science Advisor
    Gold Member

    How about you start by giving us some of your thoughts on the question?
  4. Aug 21, 2005 #3


    User Avatar

    1. A clinical thermometer has a narrow constriction in the tube just above the bulb. The expanding mercury pushes its way past the constriction when the thermometer is placed in the mouth.
    When the thermometer is taken out of the mouth the mecury does not immediately fall back to the bulb. The mecury is trapped at the temperature of the body it was placed in. This allows for the temperature to be read after it has been taken out of the mouth. The only way to return all the mecury to the bulb is to flick it back and forth.
    A normal thermometer (a lab thermometer) does not have this constriction

    2. A clinical thermometer has a much shorter range than a lab thermometer. A clinical has a range of 35C to 42C (about the range for body temp.) but a lab has a range to about 100C or 120C

    3. The cross sectional shape of the tube is a pear shape. It acts as a magnifying glass so that it is easier to see the fine thread of mercury in the fine tube. A lab thermometer doesnt have this pear shape (not that I know of).

    Last edited: Aug 21, 2005
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook