Parts of the Vernier Caliper A Caliper is simply a measuring device from a compass to intense instruments such as the vernier caliper acting caliper acting as an advanced ruler. The vernier caliper uses vernier scale to measure more precisely. This instrument provides different methods of measuring including ways to measure external or internal dimensions as well as finding depth measurements. In fact the depth measurement method of using a movable and slidable probe is so slender that it is able to retrieve data in deep canals. The lower and upper section of this scale generally uses both inch and metric measurements. Industries use vernier calipers because of its hundredth of a millimeter precision equal to one thousandth of an inch. Below describes the vernier caliper's parts and functions.
The rail (4) allows sliding to occur on the main scale (7) moving the vernier scale (3) while the fixed jaw (11) remains in place so the precise measurement is found. Also, draw back and forth (9) the instrument's jaws (parts 1 and 10) to adjust the caliper. The indicated measurement is found at the left of the vernier scale (3 and 8) either in inches or centimeters. The sliding jaw (9) and the depth probe (5) are connected to and move along with the vernier scale. Deep measurements are taken by the use of the front end of the rail (6).
1. Inside jaws: Internal length measurements are found by using this part. 2. Retainer or locking screw: This part blocks the instrument's movable parts in order to transfer between measurement methods easily. 3. Vernier scale (inch) 4. Rail (inch) 5. Depth probe: The part used in order to find depth measurements 6. Front end of the rail 7. Main scale (mm) 8. Vernier scale (mm) 9. Sliding Jaw 10. Outside jaws: This part makes measuring external lengths possible. Fixed Jaw
What are the parts of micrometer caliper and their functions? Frame, Anvil, Spindle, Spindle lock, Barrel, Thimble, and Rachet. <-NovaNet!! spindle spindle An outside micrometer consists of the following parts:
11. 12. 13.
14.
15. 16. 17.
Frame - The body of the instrument. Sleeve - Contains the vernier and scales, also houses the spindle nut and thimble assembly. Thimble - Houses the adjusting nut, ratchet and screws over the spindle nut. The thimble and sleeve assembly enables the actual opening and closing of the instrument over the work piece to enable measuring. Spindle - Attached to the thimble and protrudes through the frame. Together with the opposite anvil the workpiece is measured between the spindle and anvil faces. Ratchet knob - Used to close the micrometer over the workpiece to measure it. Lock - Used to lock the spindle when a measurement is achieved before removing the instrument from the workpiece. Vernier and scale - This is imprinted on the sleeve and spindle and is what gives the actual measurement.
Frame 18.
The frame is the primary component of a micrometer caliper. The frame appears as a roughly U-shaped piece of metal. Etched upon the frame's exterior is a legend, or list, explaining the graduations indicated on the tool's barrel. A handle protrudes from one side of the frame so that its appearance resembles a small scythe.
Anvil • Opposite the handle, on the frame's interior, a small,
flattened area called an anvil provides a stationary surface upon which objects rest. More importantly, the anvil provides a stationary point of reference for measurement--the micrometer provides accurate measurement by gauging the distance between the anvil and its movable counterpart, the measuring rod.
Barrel 19.
The barrel forms the uppermost part of the handle; the part closest to the frame's "U." The barrel is a cylindrical piece of metal, integral to the frame; the frame and barrel are molded as one piece. The barrel's circumference features marks that indicate measurement. Because the micrometer caliper measures on a micro scale, its measurements are often lengthy decimals. To save space on the barrel, the marks appear as whole numbers that refer to a legend printed on the frame's exterior.
Thimble • The thimble refers to the rotating portion of a micrometer's
handle. Twisting the thimble opens the tool's jaws for reading inside dimensions, or extends a rod for measurements of outside dimensions or depth. Markings on the thimble rotate along with the handle to align with the barrel's scale and provide a measurement.
Measuring Rod • The measuring rod, also called the spindle, extends from the
thimble. As the operator turns the thimble, the spindle pushes the object to be measured against the anvil. The spindle holds the object snug against the anvil, and a reading is taken. How to use and read a vernier caliper An ordinary vernier caliper has jaws you can place around an object, and on the other side jaws made to fit inside an object. These secondary jaws are for measuring the inside diameter of an object. Also, a stiff bar extends from the caliper as you open it that can be used to measure depth.
The basic steps are as follows: 1. Preparation to take the measurement, loosen the locking screw and move the slider to check if the vernier scale works properly. Before measuring, do make sure the caliper reads 0 when fully closed. If the reading is not 0, adjust the caliper’s jaws until you get a 0 reading. If you can’t adjust the caliper, you will have to remember to add to subtract the correct offset from your final reading. Clean the measuring surfaces of both vernier caliper and the object, then you can take the measurement. 2. Close the jaws lightly on the item which you want to measure. If you are measuring something round, be sure the axis of the part is perpendicular to the caliper. Namely, make sure you are measuring the full diameter. An ordinary caliper has jaws you can place around an object, and on the other side jaws made to fit inside an object. These secondary jaws are for measuring the inside diameter of an object. Also, a stiff bar extends from the caliper as you open it that can be used to measure depth. 3. How to read the measured value: 1), Read the centimeter mark on the fixed scale to the left of the 0-mark on the vernier scale. (10mm on the fixed caliper)
2). Find the millimeter mark on the fixed scale that is just to the left of the 0mark on the vernier scale. (6mm on the fixed caliper)
3). Look along the ten marks on the vernier scale and the millimeter marks on the adjacent fixed scale, until you find the two that most nearly line up. (0.25mm on the vernier scale)
4). To get the correct reading, simply add this found digit to your previous reading. (10mm + 6mm + 0.25mm= 16.25 mm)
4.Maintenance Clean the surface of the vernier caliper with dry and clean cloth (or soaked with cleaning oil) and stock in a dry environment if it stands idle for a long time.
How to Measure with a Vernier Caliper
A A. Inside Jaws B. Mainscale(cm) C. Vernierscale(cm) CB Figure 1-Vernier Caliper Calipers are comprised of two jaws, one attached to a fixed scale and the other attached to a sliding (Vernier) scale. In order to measure an object’s width, the object is simply placed between the caliper’s two jaws. The sliding tooth is then moved until the object is pressed tightly between the jaws. Using both scales, the width can be read to the nearest 0.005 cm (or 0.05 mm). EXAMPLE MEASUREMENT
1 2 1.8 cm + 0.090 cm = 1.890 cm The scales are read as follows (refer to the figure above):
How to Measure with a Vernier Caliper 1) Find where the 0 mark of the sliding vernier scale lines up on the fixed main scale. In this case, it is before the 1.9 cm mark. So, the first reading is 1.8 cm. 2) Find the mark on the vernier scale that most closely lines up with one of the marks on the main scale. Here, 8.5 and 9.5 are
very close, but 9.0 lines up best with one of the marks on the fixed scale. This value is the number of hundredths of centimeters (or tenths of millimeters). So, the second reading is 0.090 cm. 3) Add the two values together to get the total reading: 1.8 cm + 0.090 cm = 1.890 cm Given that the smallest division on the calipers is 0.005 cm (or 0.05 mm), what would be the uncertainty associated with the calipers? Remember uncertainty is rounded to one significant digit. MICROMETER CALIPER
Instructions 1
Read the large divisions that extend from the barrel of the micrometer. The large divisions are labeled with numbers and are usually marked on the top of the line.
2
Multiply the number of large divisions by 0.1 inches. For example, if 11 large divisions are showing, you would get 1.1 inches. 3 Determine the number of small divisions showing beyond the final large division. These are shown with smaller tick marks than the large divisions. 4
Multiply the number of small divisions by 0.025. For example, if you are two small divisions past 11, you would multiply 2 by 0.025 to get 0.05. 5
Read the number showing on the spindle of the micrometer that lines up with the line on the barrel of the micrometer. 6
Multiply the number on the spindle by 0.001. For example, if the number is 13, you would multiply 13 by 0.001 to get 0.013. 7
Add the results from steps 2, 4 and 6 to calculate the length shown on the micrometer. For this example you would add 1.1 plus 0.05 plus 0.013 to find the length to be 1.163 inches.
Instructions 20.
Preparation 1
2
Familiarize yourself with the micrometer. Although micrometers can vary in size and be calibrated for different units, they all have four main parts. The spindle is the part inside the hook that extends or retracts. The anvil is opposite the spindle, and together they clamp the object you are measuring. The thimble is the outermost part of the micrometer which you turn to extend or retract the spindle, and the sleeve is the portion between the hook ("C" shape) and the thimble. Examine the sleeve. The horizontal line drawn from the hook to the thimble along the sleeve separates two different increments of measurement. Above the line, whole millimeters are represented. Below the line, five tenths of a millimeter is marked.
3
21.
Examine the thimble. Another five tenths of a millimeter is marked around the perimeter of the thimble. Measurements are acquired simply by adding up the three different numbers. This means that two complete revolutions of the thimble equals one notch above the line, or one millimeter.
22.
4 Clean the measurement surfaces of the micrometer.
This includes both the anvil and the tip of the spindle. Rub a clean cloth or paper towel on these surfaces to ensure it's clean of debris and will give you an accurate measurement. 23.
5 Spin the thimble until the spindle is all the way closed,
and check the calibration. If it is correctly calibrated, the "0" mark on the thimble will line up with the horizontal line on the sleeve when it is completely closed.
Measuring • 6 Position the micrometer carefully. If you are measuring a
small object that you can freely move, hold it steadily between the anvil and spindle. If you are measuring a large object that is stationary, hold the micrometer steadily so that the anvil and spindle are on either side of the measured surfaces. • 7 Spin the thimble gently with your thumb until the object
you are measuring is locked between the anvil and spindle, and record the measurement. • 8 Record the number of whole millimeters. If there is a mark
on the other side of the line between the whole millimeter and the thimble base, add 0.5 millimeters. Otherwise, do not. Finally, add the number on the thimble that lines up with the horizontal line of the sleeve. The thimble measures hundredths of millimeters, so if the number 36 lines up for example, that would be 0.36 millimeters. The sum of the three numbers is your complete measurement.
Read more: How to Measure Using Micrometers | eHow.com http://www.ehow.com/how_7476448_measure-usingmicrometers.html#ixzz1yilgtN1w
