• Visit
    • Calendar
    • After Dark Thursdays
    • Exhibits
    • Artworks on View
    • Getting Here
    • Event Rentals
  • Education
    • Professional Development Programs
    • Tools for Teaching and Learning
    • Learning About Learning
    • Community Programs
    • Educator Newsletter
  • Explore
    • Browse by Subject
    • Activities
    • Video
    • Exhibits
    • Apps
    • Blogs
    • Websites
  • About Us
    • Our Story
    • Partnerships
    • Global Collaborations
    • Explore Our Reach
    • Arts at the Exploratorium
    • Contact Us
  • Join + Support
    • Donate today!
    • Membership
    • Join our donor community
    • Engage your business
    • Attend a fundraiser
    • Party at the Piers
    • Explore our reach
    • Thank you to our supporters
    • Host your event
    • Volunteer
  • Store
  • Visit
    • Frequently Asked Questions
    • Calendar
      • Today
      • This Week
      • Online
      • After Dark Thursday Nights
      • Arts
      • Conferences
      • Cinema Arts
      • Free and Community Events
      • Fundraising Events
      • Kids + Families
      • Live Streams
      • Members
      • Special Hours and Open Mondays
      • Private Event Closures
    • Getting Here
    • Museum Map
    • Reduced Rates & Community Day
    • Accessibility
    • Tips for Visiting with Kids
    • How to Exploratorium
    • Exhibits
    • Tactile Dome
    • Artworks on View
    • Cinema Arts
    • Kanbar Forum
    • Black Box
    • Museum Galleries
      • Bernard and Barbro Osher Gallery 1: Human Phenomena
        • Exhibition: Science of Sharing
          • Educator Activities
        • Tactile Dome
          • 1971 Press Release
        • Black Box
        • Curator Statement
      • Gallery 2: Tinkering
        • Curator Statement
      • Bechtel Gallery 3: Seeing and Listening
        • Curator Statement
      • Gallery 4: Living Systems
        • Curator Statement
      • Gallery 5: Outdoor Exhibits
        • Curator Statement
      • Fisher Bay Observatory Gallery 6: Observing Landscapes
        • Wired Pier Environmental Field Station
        • Curator Statement
      • PlayLists
        • All PlayLists
        • A Different Light
        • “We” or “Just Me”?
        • See Yourself in Cells
        • Greatest Hits: Gallery 2
        • Greatest Hits: Gallery 3
        • Greatest Hits: Gallery 4
        • Museum Map
    • Restaurant & Café
    • School Field Trips
      • Getting Here
        • Bus Routes for Field Trips and Other Groups
      • Prices and Discounts
      • Planning Guide
      • Reservations
        • Field Trip Request Form
      • Resources
    • Event Rentals
      • COVID-Compliant Options
      • Full Facility & Gallery Bundles
      • Fisher Bay Observatory Gallery & Terrace
      • East Gallery
      • Bechtel Central Gallery
      • Osher West Gallery
      • Kanbar Forum

      • Weddings
      • Proms and School Events
      • Daytime Meetings & Events
      • Happy Hour on the Water

      • Rentals FAQ
      • Event Planning Resources
      • Rental Request Form
      • Download Brochure (pdf)
    • Exploratorium Store
    • Contact Us
    • Español
    • 繁體中文
    • 简体中文
    • 한국어
    • Français
    • Deutsch
    • Português
    • 日本語
  • Education
    • Black Teachers and Students Matter
    • Professional Development Programs
      • Teacher Institute
        • About the Teacher Institute
        • Summer Institute for Teachers
        • Teacher Induction Program
        • Leadership Program
        • Teacher Institute Research
        • CA NGSS STEM Conferences
          • NGSS STEM Conference 2020
        • Science Snacks
          • Browse by Subject
          • Special Collections
          • Science Snacks A-Z
          • NGSS Planning Tools
          • Frequently Asked Questions
        • Digital Teaching Boxes
        • Meet the Teacher Institute Staff
        • Resources for Supporting Science Teachers
      • Institute for Inquiry
        • What Is Inquiry?
        • Inquiry-based Science and English Language Development
          • Educators Guide
            • Conceptual Overview
              • Science Talk
              • Science Writing
            • Classroom Video Gallery
              • Magnet Investigation
              • Snail Investigation
            • Teacher Professional Development
            • Project Studies
            • Acknowledgments
          • Conference: Exploring Science and English Language Development
            • Interviews with Participants
            • Plenary Sessions
            • Synthesis, Documentation, and Resources
        • Workshops
          • Participant Portal
          • Fundamentals of Inquiry
            • Summary Schedule
          • BaySci Science Champions Academy
          • Facilitators Guides
          • Commissioned Workshops
        • Resource Library
        • Meet the IFI Staff
      • Resources for California Educators
      • K-12 Science Leader Network
      • Resources for Supporting Science Teachers
      • Field Trip Explainer Program
      • Cambio
    • Tools for Teaching and Learning
      • Learning Toolbox
      • Science Snacks
      • Digital Teaching Boxes
      • Science Activities
      • Tinkering Projects
      • Recursos gratuitos para aprender ciencias
      • Videos
      • Exhibits
      • Publications
      • Apps
      • Educator Newsletter
      • Exploratorium Websites
    • Educator Newsletter
    • Advancing Ideas about Learning
      • Visitor Research and Evaluation
        • What we do
        • Reports & Publications
        • Projects
        • Who we are
      • Center for Informal Learning in Schools
    • Community Programs
      • High School Explainer Program
      • Xtech
      • Community Educational Engagement
      • California Tinkering Afterschool Network
        • About
        • Partners
        • Resources
        • News & Updates
        • Further Reading
  • Explore
    • Browse by Subject
      • Arts
      • Astronomy & Space Sciences
        • Planetary Science
        • Space Exploration
      • Biology
        • Anatomy & Physiology
        • Ecology
        • Evolution
        • Genetics
        • Molecular & Cellular Biology
        • Neuroscience
      • Chemistry
        • Combining Matter
        • Food & Cooking
        • Materials & Matter
        • States of Matter
      • Data
        • Data Collection & Analysis
        • Modeling & Simulations
        • Visualization
      • Earth Science
        • Atmosphere
        • Geology
        • Oceans & Water
      • Engineering & Technology
        • Design & Tinkering
        • Real-World Problems & Solutions
      • Environmental Science
        • Global Systems & Cycles
        • Human Impacts
      • History
      • Mathematics
      • Nature of Science
        • Measurement
        • Science as a Process
        • Size & Scale
        • Time
      • Perception
        • Light, Color & Seeing
        • Listening & Hearing
        • Optical Illusions
        • Scent, Smell & Taste
        • Tactile & Touch
      • Physics
        • Electricity & Magnetism
        • Energy
        • Heat & Temperature
        • Light
        • Mechanics
        • Quantum
        • Sound
        • Waves
      • Social Science
        • Culture
        • Language
        • Psychology
        • Sociology
    • Browse by Content Type
      • Activities
      • Blogs
      • Exhibits
      • Video
      • Websites
      • Apps
        • Total Solar Eclipse
  • About Us
    • Our Story
    • Explore Our Reach
    • Impact Report
    • Fact Sheet
    • Awards
    • Our History
      • 50 Years 1969–2019

    • Senior Leadership
    • Board of Trustees
    • Board of Trustees Alumni
    • Staff Scientists
    • Staff Artists

    • Arts at the Exploratorium
      • Artworks on View
      • Artist-in-Residence Program
      • Cinema Arts
        • History and Collection
        • Cinema Artists-in-Residence
        • Resources and Collaborating Organizations
        • Kanbar Forum
      • Center for Art & Inquiry
        • Begin Here
          • Lessons
            • Bob Miller/Light Walk
            • Ruth Asawa/Milk Carton Sculpture
          • Workshops
      • Resonance
        • About the Series
        • See & Hear
        • Past Seasons
      • Over the Water
      • Black Box
      • Upcoming Events
      • Temporary Exhibitions
      • Arts Program Staff
      • Arts Committee and Advisers
    • Teacher Institute
    • Institute for Inquiry
    • Online Engagement
    • Explainer Programs
    • Studio for Public Spaces
    • Exhibit Making
    • Partnerships
      • Building Global Connections
        • Global Collaborations
          • Projects
          • Approach
          • People
          • Impact
      • Partnering with Science Agencies
        • NASA
        • NOAA
      • Partnering with Educational Institutions
      • Osher Fellows

    • Job Opportunities
    • Become a Volunteer

    • Contact Info
    • Newsletter
    • Educator Newsletter
    • Blogs
    • Follow & Share
    • Press Office

    • FY20 Audit Report
    • 990 FY19 Tax Return
    • Use Policy
      • Privacy Policy
      • Intellectual Property Policy
  • Join + Support
    • Donate today!
    • Membership
      • Membership FAQ
      • Member Benefits
      • After Dark Membership
      • Member Events
      • May Is for Members
    • Join our donor community
    • Engage your business
      • Corporate Membership
      • Luminary Partnerships
    • Attend a fundraiser
      • Wonder Funday
      • Science of Cocktails
      • Party at the Piers
        • Event Leadership and Host Committee
    • Explore our reach
    • Thank you to our supporters
    • Volunteer
      • Benefits
      • How to Apply
      • Application for Corporate Groups
      • Application for Internships
      • Application for Professional Societies
      • Application for School Groups & Clubs
      • Our Contract
      • Application for Individuals
      • Opportunities
  • Press Office
    • Press Releases
    • News Coverage
    • Events Calendar
    • Fact Sheet
    • Photographs
    • Press Video
    • Press Kits
    • Press Visits
    • Exploratorium Logos
    • Recent Awards
    • Praise for the Exploratorium
    • Join Our Press List
  • Store
 

Learn with us online while the Exploratorium is temporarily closed. You can help us reopen—donate today.

Exploratorium
Exploratorium
  • Visit
    • Calendar
    • After Dark Thursdays
    • Exhibits
    • Artworks on View
    • Getting Here
    • Event Rentals
  • Education
    • Professional Development Programs
    • Tools for Teaching and Learning
    • Learning About Learning
    • Community Programs
    • Educator Newsletter
  • Explore
    • Browse by Subject
    • Activities
    • Video
    • Exhibits
    • Apps
    • Blogs
    • Websites
  • About Us
    • Our Story
    • Partnerships
    • Global Collaborations
    • Explore Our Reach
    • Arts at the Exploratorium
    • Contact Us
  • Join + Support
    • Donate today!
    • Membership
    • Join our donor community
    • Engage your business
    • Attend a fundraiser
    • Party at the Piers
    • Explore our reach
    • Thank you to our supporters
    • Host your event
    • Volunteer
  • Store
Science Snacks
Science activity that will allow you measure things that are too small to measure with commonly available means
Science activity that will allow you measure things that are too small to measure with commonly available means
  • Science activity that will allow you measure things that are too small to measure with commonly available means
  • Science activity that will allow you measure things that are too small to measure with commonly available means

Micrometer Caliper

Measure the thickness of a sheet of paper or the diameter of a human hair.

This simple version of a micrometer caliper will allow you measure things that are too small to measure with commonly available means. Although its accuracy is less than perfect, its capability is somewhat amazing, especially considering the cost of the materials.


Grade Bands: 
6-8
9-12
Subject: 
Engineering & Technology
Nature of Science
Measurement
Size & Scale
Keywords: 
tool
NGSS and EP&Cs: 
ETS
ETS1
CCCs
Scale, Proportion, and Quantity
Structure and Function

  • Facebook logo
  • Reddit logo
  • Twitter logo


Tools and Materials

  • One sheet cardstock (for the micrometer dial)
  • Micrometer dial template
  • Scissors (not shown)
  • Metal file or drill with grinding wheel
  • Two #10-24 hex nuts
  • One #10-24 machine screw, 4 inches (10 cm) long
  • Wood block, 2 x 2 x 3/4 inches (5 x 5 x 2 centimeters)
  • Two rubber bands
  • Two cable ties around 8 inches (20 cm) long
  • Needle-nose pliers
  • Fender washer, 3/16 x 1 1/2 inches (0.5 x 3.8 cm), hole size x outer diameter
  • Pencil or marker (not shown)
  • Drill with 1/8 inch (3 mm) drill bit
  • Two Phillips pan-head sheet-metal screws, 8 x 5/8 inch (20 x 1.5 cm)
  • Phillips screwdriver
  • Two #10-24 wing nuts
  • Two SAE 10 washers   
  • Large binder clip
  • Jumbo paper clip
  • Wooden clothespin with spring
  • Optional: wire cutters (to cut a paper clip), printer paper and glue stick (to make the micrometer dial)

Assembly

  1. Print or copy the micrometer dial template onto cardstock. Cut out the dial, and set it aside. You’ll need it again in Step 7. (Note: If your printer does not accommodate cardstock, just print onto regular printer paper and use a glue stick to attach the dial to the cardstock.)
  2. Check the machine screw to be sure the end shows a flat surface that’s perpendicular to the screw itself. You may find a small raised ridge around the edge, or possibly some irregular burrs. If necessary, use the metal file or drill with grinding wheel to flatten the surface. To work best in the micrometer, the end of the machine screw will need to uniformly contact the fender washer.
  3. Screw the two hex nuts onto the machine screw, about 1 inch (2.5 cm) apart. Lay the assembly along the top edge of the wood block, with the hex nut nearest the end of the screw, about 1/2 inch (1.5 cm) from the edge of the block. Then use two rubber bands to hold the hex-nut-and-machine-screw assembly in place (see photo below).
  4. Loop the cable ties around the hex nuts and wood block to fasten the assembly to the block. Use the needle-nose pliers to tighten the cable ties so the whole assembly is held securely together, with the fastening heads of the cable ties located at least halfway up the side of the block. When the cable ties are in place, remove the rubber bands; they will no longer be needed (see photo in Step 6).
  5. Unscrew the machine screw, and remove it. You’ll need it again in Step 8.
  6. Hold the fender washer against the face of the wood block where the flat end of the machine screw was located. Leave approximately 1/2 inch (1.5 cm) of the washer sticking up above the top of the block (the flat end of the machine screw will sit against it when it’s set in place in Step 11). With a pencil or marker, mark the position of the center of the washer on the block. Drill a pilot hole, and then fasten the washer to the block with one of the sheet-metal screws (see photo below). When the washer is in place, set the assembly aside to prepare the micrometer dial.
  7. Using the tip of a sharpened pencil, poke a small hole in the center of the micrometer dial and slide it onto the machine screw. Use the two wing nuts and the two small washers to hold the dial in place on the machine screw, positioning the dial about 1 inch (2.5 cm) from the head of the screw (see photo below).
  8. Screw the machine-screw-and-dial assembly back through the two hex nuts on the top of the wood base until the end of the screw is fairly close to the fender washer, but not in contact with it. It should be about 1/4 inch (0.5 cm) away.
  9. Attach the binder clip to the bottom of the wood base, and then remove the clip’s handles (see photo below). This will give the assembly a flat base so the micrometer can stand up by itself.
  10. Using the needle-nose pliers, bend the jumbo paper clip to make a reference indicator for the dial (you can cut the paper clip if necessary). Drill a pilot hole and use the remaining sheet-metal screw to attach the bent paper clip (see photo below).
    ​
  11. Attach the clothespin to the head of the machine screw (see below). The clothespin will standardize the force of the end of the screw as it comes into contact with the washer. Gently push on the clothespin to turn the screw so it touches the washer, and stop when the clothespin starts to slip.
  12. With the screw remaining gently in contact with the washer, lightly loosen the wing nuts holding the dial in place. Rotate the dial to line up the zero with the reference indicator, and then tighten the wing nuts to hold the dial in this position. Once again, use the clothespin to tighten the screw until it slips, and check the alignment of the dial. (Be aware that, as the clothespin turns, the soft wood of the block may respond by traveling along the screw toward the dial, so you may need to move the clothespin each time so it always sits next to the head of the screw.) Repeat this calibration adjustment as necessary until the reference indicator consistently reads zero on the dial. At that point, your micrometer caliper is ready to go (see photos below).
    ​

(Note: As an alternative to calibrating by loosening the wing nuts to move the dial, you could also just initially make sure the zero on the dial is somewhere near the bottom, and then adjust the indicator by moving it or bending it until it lines up with the zero mark.)


To Do and Notice

Tighten the screw with the clothespin until the clothespin slips and the end of the screw is up against the fender washer. The zero mark on the dial should be lined up with the reference indicator. Loosen the screw a little less than one whole turn (until the zero on the dial is almost to the reference mark again) and insert a piece of paper between the end of the screw and the washer. Tighten the screw again, once more using the clothespin until it slips and the end of the screw is up against the paper. Then read the dial.

Each mark on the dial represents about one one-hundredth of a millimeter, so the mark that lines up with the reference indicator indicates the thickness of the paper in hundredths of a millimeter. Ordinary copy paper usually has a thickness of between ten to fifteen hundredths of a millimeter (10 to 15 on the dial).

Try measuring other objects. Some things to consider are an index card, a paper clip, a piece of thin spaghetti, regular or heavy duty aluminum foil, nylon fishing line, wires of different gauges, plastic bag material, or even a human hair.

Periodically check to make sure the reference indicator still reads zero when there is no object in place. If it doesn't, then recalibrate the dial.

If the object you’re measuring is larger than one millimeter, you’ll have to keep track of how many turns you have to loosen the screw (and therefore the dial) before measuring the object, and then add the appropriate amount to the dial reading. Each complete turn of the screw moves the end of the screw one millimeter.

You can increase the reliability of a measurement by doing multiple trials and finding their average, rather than relying on a single trial.


What’s Going On?

The 24 in the specification of the screw (#10-24) indicates that there are 24 threads per inch. This is known as the "pitch" of the screw. It means that it takes 24 complete turns of the screw to move it one inch.

One inch is equal to 2.54 centimeters, or 25.4 millimeters. So there are 24 threads in 25.4 millimeters. This is close to 1 thread per millimeter. And though it is off by 1 millimeter in about 25 millimeters, that works out to just 4 millimeters in 100, or 4%, which is not bad considering the cost of this instrument!

Since there is one thread per millimeter, then one complete turn of the screw moves the end of the screw 1 millimeter. The dial divides one turn of the screw into 100 parts, each of which represents 1/100 of a turn. Since a whole turn is a whole millimeter, each division on the dial represents one hundredth of a millimeter, or 0.01 millimeter.


Going Further

The micron is a unit of measurement still in common use in some areas of science and technology, but it is no longer an official SI unit. How does a micron relate to a meter, a millimeter and a micrometer (the SI unit, not the instrument you built)? How many microns are represented by one division on the dial?

Familiarize yourself with the following terms: sensitivity, precision, accuracy, deviation. See if you can apply them to your micrometer caliper.

Making and/or using this micrometer caliper can provide unique hands-on insight and experience in the measurement of very small things, but with limitations on precision and accuracy affecting its use as an everyday working tool. Pre-digital mechanical micrometer calipers operated on the same principle, though with greater precision and accuracy, but were relatively expensive. Now, however, there are inexpensive digital calipers with exceptional capabilities that provide a useful working tool for many aspects of science education.


Resources

The inspiration for this micrometer came from the original PSSC Physics materials created by MIT’s Physical Science Study Committee in the late 1950s and early 1960s.



Related Snacks

Science activity that demonstrates finding the approximate masses of very small things
Microbalance

Make a balance that weighs very light things.

Science activity measuring density of a liquid
Eyedropper Hydrometer

Construct a simple hydrometer to compare the densities of solutions.

Science activity detecting electric charge
Electroscope

Build an electroscope to detect electrical charge using straws.


Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
Attribution: Exploratorium Teacher Institute

  • Education
    • Teacher Institute
    • Tools for Teaching and Learning
      • Science Snacks
        • Browse by Subject
        • Special Collections
        • Science Snacks A-Z
        • NGSS Planning Tools
        • Frequently Asked Questions

Connect with us!

  •   Sign up for our educator newsletter
  •   Follow #ExploEDU
  •   Teacher Institute YouTube
  •   Teacher Institute Facebook
  •  teacherinstitute @exploratorium.edu
Exploratorium
Visit
Join
Give

Pier 15
(Embarcadero at Green Street)
San Francisco, CA 94111
(415) 528-4444

Contact Us

  • Plan Your Visit
  • Getting Here
  • Calendar
  • Tactile Dome
  • Store
  • About Us
  • Become a Member
  • Donate
  • Event Rentals
  • Jobs
  • Volunteer
  • Press Office

Get at-home activities and learning tools delivered straight to your inbox

The Exploratorium is a 501(c)(3) nonprofit organization. Our tax ID #: 94-1696494
© 2021 Exploratorium | Terms of Service | Privacy Policy | Your California Privacy Rights |