How do I Read a Mercury Basal Thermometer?

Most people no longer own mercury thermometers because you have a hazardous spill if it breaks. Mercury thermometers are almost impossible to buy anymore because mercury is toxic and mercury thermometers are actually banned in many places.



If you want an extremely accurate temperature reading, a glass basal thermometer is a necessary tool. Basal thermometers are accurate and marked to a tenth of a degree. This is important if you are trying to track ovulation either to achieve or avoid pregnancy. The basal thermometer is used because you want to accurately track a temperature rise of .2 degrees Fahrenheit.



Most basal thermometers available today are mercury free and contain silver Gerathem.

Things You'll Need

• Basal thermometer

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Instructions

Reading a Mercury Basal Thermometer

• 1

  Shake the thermometer down. Grab the thermometer firmly by the glass end and shake it sharply and firmly in a downward manner. Make sure to keep a firm grip on the thermometer and avoid hitting anything with it, or your thermometer will shatter. Shake the thermometer down until the silver mercury line falls below 96.5 degrees Fahrenheit. Place the thermometer beside the bed and go to sleep.

• 2

  When you wake up, place your thermometer into your mouth under the tongue. This reading must be taken before you get out of bed. Close your mouth firmly but gently around the thermometer. Do not bite the thermometer or it will shatter.

• 3

  Allow the thermometer to stay in your mouth for five to seven minutes. Resist the impulse to pull it out and check it every few minutes. It isn't fast like an electric thermometer. Your body is slowly warming the mercury, and it will rise until it reaches the correct reading.

• 4

  Remove the thermometer and angle it toward a light source until you can see where the silver mercury line ends. The temperature gauge is on the side of the thermometer. The line closest to the end of the silver line is your basal temperature.