gardening with Kids Email Sign-up Catalog Request Register or LOGIN View Cart

LEADERS IN

PLANT-BASED

EDUCATION®

gardening with Kids

Questions? Contact us:

800-538-7476

customerservice@garden.org

Home | Make a Hair Hygrometer

Browse Products
Home
NEW Products!
Best Sellers
BONUS Bundles
Birds & Trees
Books & Posters
Butterflies & Insects
Composting
Containers & Raised Beds
Cultural Studies
Curriculum
Kits by GWK
Furniture & Ornamental
Gardening with Teenagers
Greenhouses & Sheds
GrowLab® Light Gardens
Habitats & Wildlife
Health & Nutrition
Indoor Classroom Activities
Observation Tools
Outdoor Classroom Activities
Preschool Gardening
Seed Starting
School Garden Packages
Tools & Equipment
Watering
Weather Investigations
Worms & Vermicomposting
Clearance

Make a Hair Hygrometer

Did you ever notice that humidity and "bad hair days" often go hand-in-hand? When humidity increases, the length of hair strands also increases. (Typically, straight hair goes limp and curly hair frizzes!) Scientists in 1783 used that concept to create a cool tool — a "hair hygrometer" — for measuring changes in humidity. Here's how your students can make one:

  1. From the piece of oak tag or thin plastic, cut a triangular pointer about 6 inches long. Cut two slits at the bottom of the pointer about 1 inch from the left edge. Tape or hot glue a dime onto the triangle about 2 inches from the pointer's left edge.
  2. Cut two slits on the cardboard's top edge about 1/4 inch apart and 1 inch from the left side.
  3. Attach the pointer to the cardboard with a pushpin. Place it about 1/2 inch from the left edge and about 3/4 of the way down the side.
  4. Attach the hair strand by sliding it through the 2 slits at the top of the cardboard and those at the bottom of the triangle. Use tape or hot glue in both sets of slits to keep the hair in place.
  5. Push the pin through the pointer hole so the hair is slightly stretched when the pointer is horizontal. Wiggle the pointer up and down to make sure it can move freely. (The hair should hang vertically and the pointer should be horizontal.)
  6. The pointer on your hygrometer is now set to show changes in humidity. When there is a lot of moisture in the air (high humidity), the hair gets just a little bit longer. That makes the pointer droop lower. When the air gets drier (low humidity), the hair gets a little bit shorter and the pointer goes higher.
As an activity extension, consider having students check relative humidity on the computer or radio for several days. Each time, they can draw a line at the tip of the arrow on their hair tool and write down the actual humidity.

Here are some questions your weather sleuths might investigate: Does the air feel different when the humidity changes? Do we notice any related changes in plants? Is there a relationship between shifts in humidity and the general weather? How do nighttime air temperatures, humidity, and the occurrence of dew or frost relate to one another? How do classmates' hairstyles vary with changes in the humidity?

For more weather activity ideas, check out:

Making Weather Tracking Tools
Weather Matters
Branch Out with Weather and Climate

Sort by:    


Customer Service
Ph: 800-538-7476
Email: customerservice@garden.org
Fax: 802-864-6889
Pinterest Facebook Twitter RSS All purchases support nonprofit
grant programs in schools and
communities nationwide