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