A caliper is a special measuring tool that primarily consists of two adjustable legs or jaws. While you use them for measuring different materials, how sure are you of their accuracy?
The best digital caliper for accurate measurements will provide you with four readings: external and internal dimensions, depth, and step. Let’s take a closer look at how this tool does in terms of accuracy.
Do Calipers Make Accurate Measurements?
Generally, yes, calipers are accurate. The most decent ones boast an accuracy within +/-0.001 inches or 0.02 millimeters. As you can imagine, this is enough to ensure your workpiece fits nicely within the material you’re using.
There are different types of calipers, but the most popular are the digital versions. They are easy to use and automatically convert the readings between metric and standard measurement systems.
The key to finding the best digital caliper is knowing what your needs are. This way, you don’t end up buying one that doesn’t match your project’s requirements.
How To Get Accurate Readings With a Caliper
As mentioned, a caliper has two pairs of jaws. You use the first pair for measuring the internal dimensions of an object, and the other pair is for measuring external dimensions. This tool also comes with a depth robe and a metal sheet that you can use to quantify hole distances.
Outside Measurement
The most basic application of a caliper is for measuring the outside dimensions of an object, say, a watch, a coin, or a screw head. To do this, you simply slide the jaws of the caliper until both ends touch the workpiece.
While it’s easy, you may not get accurate measurements if you don’t do it properly. Additionally, if there’s dirt on the object to be measured or on the jaws of the caliper, the measurement won’t be accurate.
Inside Measurement
The smaller jaws or legs on top of the caliper are used to measure inside dimensions. Do note that it can be challenging to keep things lined up correctly when measuring internal spaces.
For an accurate measurement, slide the caliper closed and place the inside jaws into the space to be measured. Slide the jaws apart as far as they can go and make sure that the calipers are not tilted to get better readings.
Depth Measurement
A caliper has a depth blade that extends out of the far end. To measure the depth, position the rod so that it is flat against both the bottom of the hole and its internal side.
Then, press the machined end against the top of the object or hole you want to measure. Open the caliper until the blade touches the bottom. Do this by moving the thumb screw gradually. Turn the lock screw to tighten the jaws to remove the object and take the reading.
Step Measurement
Although it’s the least used application of a caliper, it’s extremely helpful for many DIY projects. To get accurate measurements, ensure that the upper step is perpendicular to the edge of the hole, object, or workpiece you are measuring.
Additionally, the fixed jaw should make contact on the lower step. Tighten the screw so that you can remove the workpiece and get your reading.
Tips To Get Accurate Caliper Readings
Calipers are measuring tools that can provide accurate results when used correctly and for the right application or project. Whether you’re measuring outside, inside, depth, or step dimensions, follow these tips to ensure accurate readings.
1. Zero out the display before using the caliper.
Open and close the jaws a couple of times to check the zero setting. If there are a couple of counts of difference, re-zero the display setting and try again until you’re sure there is a good zero condition.
2. Take good care of your caliper.
Check your caliper often for wear, burrs, and scratches, particularly on the jaws. A simple way to do this is to pass a master disc along the jaws. You’ll also want to calibrate your tool at least once a year. Do it more often if you use your caliper more frequently.
3. Know its limits.
While calipers are versatile tools, they aren’t right for every job. Digital calipers read in 0.001 inches or 0.0005 inches. If your project requires a tolerance tighter than ±0.002 inches, you should use a micrometer instead.
Another thing, take note that digital calipers have capacitor sensors that could malfunction when they come in contact with liquid or when used in humid conditions. In such a case, you should use a waterproof caliper.
Are Calipers More Accurate Than Rulers?
Yes, absolutely. While you can measure most objects with a ruler, a caliper is a much better option. The biggest advantage of a caliper is the fact that it has scales of measurement built into the tool. With this, you can get more precise measurements than simply using a ruler.