Precision Measuring Tools
• The Ruler • The Micrometer• The Dial Caliper• Each tool can measure things in smaller
and smaller increments• From larger increments-the Ruler
distances in inchs, to very small increments distances in thousandths of an inch-the Dial Caliper
The dial caliper is: a precision measuring instrument.
The caliper’s blade graduations are:
in inches and tenths (.1) of an inch.
The caliper’s dial graduations are:
in thousandths (.001) of an inch.
One full revolution of the pointer on the dial equals:one hundred thousandths (.100).
Precision Measurement
• To measure something precisely you are making the measurement and comparing it to some accepted dimension or number called the Standard
• When something is measured Accurately you get the same number every time.
• Measurements can be Accurate but not Precise
Blade
Inside Measuring Faces
Outside Measuring Faces
Dial
Fine Adjustment Screw
Dial Clamp Screw
Clamp Screw
Precision Technical Drawings
• Go back to the previous slide and draw the Dial Caliper in your engineering notebook, making sure to label all of the parts.
Step 1Step 2Step 3
Read inches
Read tenths of an inch
Read thousandths of an inch
Blade (0”-6”)
Blade (.0”-.9”)
Dial (.000”-.099”)
2
3
028
2 328Now add…
Step 1Step 2Step 3
Read inches
Read tenths of an inch
Read thousandths of an inch
Blade
1”-6”
Blade
.0-.9”
Dial Dial
.001”-.099”
2 3 2 8
Reading a Caliper Practice
Step 1 Read inches 4
Step 2 Read tenths of an inch .5
Step 3 Read thousandths of an inch .007
The new dial reading is?_________
Team Practice-50 pts.
• Step 1 make up 3 caliper readings that includes inches, tenths of inches and thousandths of inches. 10 pts
• Step 2 give your 3 caliper readings to your partner 5 pts.
• Step 3 after 5 minutes collect your caliper readings and check the results with your partner
• (did they record the reading correctly) 15 pts.• Step 4 jot down a note about what you and your
partner learned about precision instruments and reading a dial caliper. 20 pts.
Dial Caliper Practice
• The new dial reading is 4.507