Caliper Measurement 101: How to Properly Use and Read a Caliper

How to Properly Use and Read a Dial Caliper

Though the slide calipers are the most widely known member of the caliper family, there are other types of calipers available in the market. So what’s the difference, right? And how do you read them? Is it like rocket science? Well, let’s find out together. Today we will know how to properly use and read a dial caliper, including all the others. And we will know the difference between them. So without any further ado, let’s start.


What is a Caliper?

A Caliper is a special kind of measuring tool. Though it is a lot like your usual ruler, it has a different measurement system that assures a more accurate measurement than any other ruler. The history of using a caliper to take precise measurements goes thousands of years back in the past. They are used in many disciplines, including medicine, science, mechanical engineering, woodworking, metalworking, and forestry.

If you want to measure the distance between two points using a standard ruler, the smallest distance you can measure is usually 1mm if the distance is smaller than that, the ruler becomes useless. A caliper is your best bet if you want to measure a smaller distance than that with great accuracy.


Types of Calipers

Depending on the task the complete, there are mainly 4 types of calipers available in the market. However, they all do the same thing, measurement. The key difference lies in the measurement scale. Let’s have a look at each type of calipers you can get your hands on.


Dial Calipers

These are pretty analog. Just like a pressure gauge, they display the measurement with an indicator needle. The dial can record and measure the final fraction of a millimeter or inch. The gauge can be slid along the stational ruler. You have to combine the reading from the dial indicator with the reading given on the scale to get the final measurement reading.


Vernier Calipers

If you need accurate and step measurements for your project, this is the one you should get. Due to their accurate measurement capability/extreme precision, these types of calipers are widely used in navigation, scientific projects, mechanical work, and surveyors across the globe. This type of vernier scale calipers offers a combination of the main scale and an auxiliary (Vernier) scale.


Digital Calipers

If you are a tech-savvy person, this type of caliper is a great fit for you. Instead of relying on a rack and pinion mechanism, electronic digital calipers use an internal microprocessor to calculate the position of the jaws. Then they display the readings over a digital display screen.


Spring Joint Calipers

Though they are one of the calipers, they look a bit bizarre. They are primarily made of two legs, a spring, and an adjusting nut. And they need to be checked against a ruler because they don’t have one engraved on them. You can adjust the space between the legs by twisting the lock screw and nut.


How to Use a Caliper

Now let’s have a look at how we can use these calipers to measure something accurately. Shall we?

Taking step measurement using a caliper is fairly straightforward. We need to learn about all the parts of a caliper and its function to understand how this works. So let’s get started.

Usually, a caliper is a ruler made of stainless steel and with some extra parts. There is a thumbscrew/adjusting screw and/or a locking screw to lock the caliper reading. And there is a vernier scale attached to some of the calipers. And last but not least, er have a depth gauge/ depth rod to measure depth.

There is a different workflow for each type of calipers you are using. Though, except for the spring caliper, the process is pretty much similar for the other types of the caliper. You take reading with different parts of the scale and combine the reading to get the final measurement.

The only thing that differs with a spring caliper is to adjust the legs between the distance you are trying to measure, give it a nice twist locking up the legs, and then compare the distance over a traditional and precise ruler. That is pretty much all there is to it.


How to Read a Caliper

Now let’s dive in deeper into measuring minuscule distances with great accuracy using decent calipers. There are three main methods you’ll need to learn to nail taking measurements with a caliper tool. So let’s have a look at each different method.


How to Read Dial Calipers?

Here’s how you take measurements on a dial caliper:

  • Close the jaws and make sure that the indicator points to “0” on the dial face.
  • Adjust the jaws to measure the object.
  • Look at the sliding jaw and note the last main scale graduation that it passed.
  • Determine which number the hand is pointing to.
  • The final reading is the sum of these two readings.


How to Read Vernier Calipers?

This one is a bit tricky. Here goes:

  • Read the large number division first from the main scale to the left of the “zero” of the Vernier scale.
  • Find the largest whole inch mark to the left side of this index line.
  • Use the end of the zero mark on the Vernier scale as the index line and find the largest .100-inch mark to the left side of this index line.
  • Now, check the Vernier scale.
  • Note how the lines on the Vernier scale match up with the lines on the main scale. Remember, only one of these lines will match up correctly.
  • Record the whole number of .025-inch increments to the left of the index line using the end of the zero mark on the Vernier scale as the index line.
  • Now add the two readings to get the final measurement.


How to Read Digital Calipers?

These tools work fine whether you follow the metric scale or the international standard. This Is how you read them.

  • If in inches mode, the far-left number before the decimal point is whole inches.
  • The numbers right of the decimal represent tenths, hundredths, and thousandths, respectively.
  • A fourth number will pop up to the left of the decimal point when the slide is between thousandths, indicating 5 tenths of thousandths.


What’s the Use?

It’s very unlikely that you carry a caliper around and measure whatever comes in your sight, right? So what’s the actual use of this thing? Many of you might wonder. But Let me assure you that modern civilization’s pinnacle stands for accurate measurement, and calipers are used in almost every major aspect of life. Here are some questions for you. With Regular scale/ruler —

  • Can you measure the size of your smartphone’s CPU?
  • Can you use pieces of medical or lab equipment that are not accurately measured?
  • Can you create mechanical parts without accurate measurement?
  • Can you measure the diameter of thin slices of wire?
  • Can you curve any object without precise measurements?

If all your answers are “No,” then I guess you understand the importance of tools like a caliper. Though they are mainly used in scientific labs and engineering schools, they influence all our lives. If you want to take precise measurements of the inside, outside, depth, and step measurements of various objects, a caliper is the best option for you.


Over and Out

I hope you’ve had a clear picture of this versatile measurement tool named calipers. Whether you want to measure the distance between holes, or need critically accurate measurement, having calipers around helps a lot.

No More Today. Please share your opinions and experiences with us in the comment section below. Thanks for reading this far. Now you know how to properly use and read a dial caliper. Congratulations.

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