How to Read a Thermometer

Whether you are a gardener deciding when the ground is ready to plant, a parent with a sick child or you just want to gauge today's weather for purposes of selecting clothes and activities, knowing how to read a thermometer comes in handy. An average normal body temperature is 98.6 degrees. Therefore, fever thermometers will start with a nine at the lower end to indicate 90. The single-digit numbers or heavy hatch marks following represent 95, 96, 97, etc. About halfway on the scale, you find 100 degrees and continue counting in the same manner. The smaller hatch marks between the degrees stand for tenths of a degree. Count these hatches to determine if it counts by one-tenths or two-tenths.

Things You'll Need

• Thermometer

Show More

Instructions

Fever

• 1

  Check the scale on the thermometer display before trying to use it.

• 2

  Take the patient's temperature as recommended by your doctor or consult the Mayo Clinic's recommendations (see Resources).

• 3

  Hold the thermometer level and perpendicular to your body at eye level. Look for a red or silvery line of liquid. Check to see if it meets or extends beyond the 100 mark to determine if your base number is 90 or 100.

• 4

  Count full degree marks beyond 90 or 100 as appropriate and add to the base number.

• 5

  Count tenth of a degree marks per the scale you determined above and add to the total. This is your final temperature.

Weather

• 6

  Check the thermometer's scale. Note whether it is in Celsius, Fahrenheit or both. Look at two consecutive labeled hatch marks to figure out how many numbers lie between them. Count the number of hatch marks between the two and figure out the increments.

• 7

  Hang the thermometer on a location where it can hang level. Give it at least 30 minutes to acclimate to its environment.

• 8

  Examine the tube. Look for the line of colored liquid rising inside.

• 9

  Estimate the temperature by determining between which two decades it falls.

• 10

  Start with the lower decade and count hatch marks by the incremental scale you determined above. Add the result to the starting decade. This is your final temperature.