Cursor measuring simple structure, easy to use, to meet the general accuracy of the measurement requirements, the machinery manufacturing industry is widely used in measuring tools, measure the inside and outside the size, height and depth.
Generally by use of the cursor measuring caliper, height gauge, depth vernier caliper.
The use and maintenance of vernier caliper
First, the structure and use of vernier caliper
Vernier caliper (the caliper) and more types of contour structure, the company is the third most commonly used two-sided with a caliper and caliper
Structure: The knife-edge within the jaws, outer jaws, foot frame, fastening screws, the depth of the measuring rod, travel rod, the main gauge
Purpose: measure the internal and external dimensions, depth, pitch, ring thickness, groove
Structure: the amount of feet outside the edge, outside the jaws, the jaws arc, vernier, the main gauge, tighten the screws, micro devices
Purpose: measure the internal and external dimensions, pitch, ring thickness, groove
Second, the use
(A), pre-use check
1. Check Interactions: pull-foot box, vernier, and micro-scale box should be able to slide together along the main scale and flexible, non-stuck phenomenon, the role of normal and reliable fixing screws.
2. Check the measuring face: with a clean cotton, silk or soft cloth to wipe the measuring surface, facing the light, check the amount of claw measuring surface, should not significantly close the gap and after light exposure.
3. Check the zero position: the cursor line and the main scale zero-zero-engraved engraved engraved line and the cursor line and the end of the main scale engraved on the corresponding line should be in the "0" bit alignment.
When in doubt, cross check the results of measuring room treatment.
(B), the reading method
The groove vernier caliper principle: the reading of the cursor in part by measuring the body and the vernier scale, whose principle is to use ruler engraved engraved line spacing and line spacing difference between the cursor to the decimal reading.
Line spacing is usually a ruler engraved as 1mm, ruler engraved lines (n-1) is equal to the width of frame n frame cursor the width of groove, the groove pitch cursor b = (n-1) × a / n. The ruler engraved engraved line and the cursor line spacing width difference (ie, the cursor degree value) i = ab = a / n, according to this principle, move the cursor along the ruler, you can make the cursor on the ruler and align in a moment obtained size of the measured length of the integer and fractional parts.
1. First read an integer: 0 read vernier scale engraved line on the left of the main value of the first line.
2. Read decimal: see the first few Vernier groove groove aligned with the main scale, ordinal number of grooves aligned vernier scale value multiplied by the derived fractional part.
3. Will be added to read integer and decimal, derived measurement dimensions.
4. Readings Precautions: see eye to read a vertical groove to prevent reading errors caused by partial view; when there is no groove completely aligned, the comparison should be found together on line to read the inscription.
(C), the proper use of vernier caliper
1. Measuring small pieces, the left hand part, right hand caliper; measuring large, the hands holding caliper, left the amount of the main claw foot contacts with the part is good, right hand frame tour activities were measured.
2. Measuring outside dimensions, should be first measured the amount of jaw opening than the large size, measuring the size, should be first measured the amount of feet smaller than the opening, then slowly push or pull the foot box , so that activity levels measured surface contact claw gently, and reading, measuring the hole caliper jaws contact hole wall should be axial, not skewed.
3. The amount of contact with the DUT claw, do not force too much force should be exactly the size of the two jaws can be exposed to the measured surface. Such as excessive force, activity will be tilted at an angle claw, resulting in measurement are not allowed. DUT claw to try to measure the amount of root surface discharge to reduce the impact of measuring force.
4. The amount of claw contact with the measured surface, the gently waving claws of activity to find the minimum size (external dimensions) or the maximum size (in size).
5. Measuring the size of circular arc feet, pay attention to read the above dimensions should be added after the arc paw thickness dimensions.
6. Using micro travel box with a caliper, in the amount of claw quick contact with the DUT micro screws tighten, and then rotating micro nut, so that the vernier measuring jaw movement to both surface and volume is measured surface contact until the final tightening and vernier reading.
7. When tightening the screw vernier caliper to take down the readings, although the easy reading of the caliper to measure surface but easy to wear, except when necessary, generally do not have this method.
8. With a caliper measurement of the workpiece depth sounding rod, should be the end of the caliper perpendicular to the top of the pressure to the workpiece surface, and the decline in activity claw gently contact hole or bottom, and then reading. Around, careful not to tilt.
9. To get the correct measurement results, the larger the size measurement of the surface location to a few more measurements.
(D), the cursor type measuring maintenance
Large caliper (300mm and above range) should not vacant square, in order to avoid bending.
Other maintenance and maintenance specification by the implementation of universal measuring tool.
Universal measuring tool maintenance specifications
1. Do not oil stone, emery cloth and rub the surface of measuring surface and the groove part of the measurement, measurement of non-maintenance personnel, non-demolition, alteration, repair measuring tool.
2. Measuring the storage place should be kept clean, dry, no vibration, no corrosive gas, away from the thermometer of the range of the place or places where magnetic fields. Storage box measuring gauges to be clean and dry, not allowed to store other items in the box. Measuring with a cooling fluid into the forbidden box.
3. Do not touch the measuring tool measuring surface, such as hand sweat wet will pollute the measurement of surface dirt, making it rust. Measuring box and not allowed without the other instruments mixed together, so as not to bruise measuring tool.
4. After measuring tool used to clean, loosen the fastening device, when the long-term not more than in January when the measurement surface to be coated in rust oil. Gauge when not in use, to put the box, not separation, storage time should not make contact with the two measuring faces.
5. Not allowed to claw tip of the caliper as a designated amount of needles, compass or other tools, people are not allowed to twist the two jaws are not allowed to use the measuring tool as card board.
6. When the workpiece surface burr, the burr must go to the net, then measured. Otherwise it would be measuring tool wear, and also affects the measurement accuracy.
Depth vernier caliper
Depth gauge for measuring the ladder holes, blind holes and groove depth.
1. Measuring surface is relatively large, pay attention to wipe clean.
2. Check the zero before measuring: measurement of the foot box is placed on the plate, so that the body with the flat-foot contact, look at the zero position is correct.
3. Measurements of the measurement of the foot box is placed on the workpiece, the ruler will not tilt, the left hand to help foot box, right foot down to push the body, lower body and the measured foot contact surface, you can read. Screw fastening can also be good ruler to take up reading.
4. Depth gauge and vernier caliper readings on the same principle.
5. Maintain universal measuring tool according to the implementation and maintenance specifications.
A high degree of vernier caliper
Mainly used to measure the height of foot height of the workpiece, the relative position and precise lines.
1. Check the zero before use. First clean the bottom, on the plate, the amount of claw contact with the tablet, the cursor should be the main scale zero-line zero-line alignment.
2. By measuring the height of crossed jaws, push the claw-foot frame to the dash slightly higher than the test piece size, tighten the screws micro-devices, micro-rotating nut, so that crossed claws and being measuring surface contact, can be read.
3. By measuring the amount of claw measurements of high altitude, face to measure the amount of claws, values can be read directly from the ruler, such as measuring the amount of claw on the face, the measured size should be read from several feet with the volume of paw thickness dimensions.
4. Do not box out on a high foot sideways to avoid bending.
5. Move the height gauge should be primary Torquay seat, one hand on the main scale, vertically or horizontally are not allowed to mention the main scale.
6. Other maintenance and maintenance specifications by the implementation of universal measuring tool.
Abbe principle: when the reference axis and measurement axis is not the same on a line that does not meet the Abbe principle.
At this point, when the reference axis and measurement axis with a tilt angle φ, will produce a square error, as shown:
If the base line and measure the distance between lines L, tilt angle φ, the resulting measurement error is: △ L = L × tgφ ≈ L × φ