Precision measurement takes an important key role when it comes to high-quality and precise product manufacturing. There are a lot of aspects to consider as well.
During manufacturing, everyone desires error-less production generated by the machine. But to get that expectation, of course, we require a certain reliable measuring instrument to make sure the machine is in proper condition.
A metal lathe; for example, the same thing goes to it. When we use the metal lathe to make tools, we require a dial indicator or test indicator to inspect that the roundness of the head is in proper condition. Due to the head roundness impacts the final result, this part is for sure important to check out before the work.
Unfortunately, what if the dial indicator is not reliable to do that because it decays inside? How to know that the dial indicator is always in proper condition? Therefore, we need calibration.
That said, to understand whether a particular instrument decayed or not, we must calibrate them. In this article, we are going to discuss the dial indicator calibration and its process so that you could follow and apply it to your dial indicator.
What is Calibration?
Calibration is a process where the measured values compare the standard value and find the tolerance range. In this process, a measurement device is compared to a traceable reference device.
It’s known that traceability is a condition where no links are missing to the real agreed reference standard. To get more detail about the traceability standard, you could visit our page here.
We agree that dial indicators function to measure the relative positions onto the object surface. So, while manufacturing, we must check whether our dial is ready for the measurement or not. This process of checking is known as the calibration process.
Why is Calibration So Important?
Dial indicators are made of several gears and pinions. While using the dial indicator, gear meshes gear all the time. It has a mechanical life. In some time, it can decay inside while meshing with the others. As a result, we must replace them after a period of time.
Since dial indicators are used in both the educational and industrial sectors, some main importance of calibration can be described as the following:
- Ensures the quality of the products: To make sure our instrument works fine, we require calibration. Ensuring the tolerances in the instruments, we can make sure the quality of our products. We know if the tiny dimension has defects while manufacturing, it may cause danger while using the product. That’s why while manufacturing we have to consider the calibration.
- Ensures the quality of the study: The basic of learning grows from childhood. Students start learning what is dial indicator in this period. They have fantasies on the results and calculations they get from the lab. If their results are not satisfactory, they will lose hope. That will be the biggest mistake of a country. So, to ensure the better quality of the study, the lab teachers must calibrate their instruments in time.
Besides, there are more benefits of calibration, such as it ensures safety, it determines the replacement period of the instrument, etc.
When Should Calibrate the Dial Indicator?
Dial indicators degrade with time and use. It depends on how often we should calibrate our dial indicator. Depending on the following aspects, we can determine the calibration time.
- Industrial Uses: Normally uses of dial indicator in this sector is more often than the other. So, the calibration in this sector should be more often too. There are many companies usually calibrate their instrument once a month, some do it once a 2 month, etc. depending on how frequently the instrument is used.
- Workshop Uses: workshops don’t contain products like the industry. Normally they make tools for the household. Their usages of the instrument are less often than the industry. Therefore, normally they calibrate their instrument once a 6 month or once a year depending on how frequently they use their instrument.
- Educational Uses: In the college or University, these instruments are normally kept in the measurement laboratory. Students normally use this equipment once a week. Most of the time in a year it is not used. So, in this case, the calibration time can be less than the workshops or industries such as once a year or 2 years depending on the University programs.
Why NIST Traceability Matters
NIST or National Institute of Standards and technology is a physical science laboratory. The main task of this institute is to promote industrial competitiveness.
NIST traceability matters on the dial indicator because no other calibration certificate can be as reliable than the NIST traceability certificate. Though Mitutoyo and other renowned companies provide their traceability certificate (from their labs), NIST traceability can promise us the quality and the accurate product.
Therefore, when your measuring instrument requires a NIST certificate to work for professional jobs, it’s common that you have to pay an extra amount of money for a request of NIST certificate of calibration.
In this case, when the instrument arrives at you, the instrument is delivered with the certificate of calibration.
Is this a must? In our perspective, this is not a must. You could still keep running your measuring instrument without this certificate. However, a typical professional job requires this certificate. In case you work in your workshop, you could rely on the certificate issued by the company lab of that instrument.
How to Calibrate A Dial Indicator at Home?
On one hand, requesting a calibration certificate is an expensive way and takes some process, but on the other hand, you must calibrate your dial indicator as soon as possible.
To ensure that the dial indicator is in good condition, you are possible to get an easy way to successfully calibrate your dial indicator. While there are some simplified ways of calibration, the most common way is the calibration using the block gauge.
In this process, we will need a gauge stand, a surface plate, and appropriately sized gauge blocks. The dial indicator is mounted on the gauge stand on the surface plate. The gauge block is placed on the surface plate.
The gauge block has its standard value according to the ANSI. However, you have to measure consecutive values from your dial indicator. And then you’ll find an average of them.
Later on, we judge our values with the standard one and find the tolerances of our dial indicator. For example, Our standard has 0.05″ of a part and our dial indicator finds 0.046″. Now we see that our dial indicator has an error of -0.004″.
You must make a document to note down the results. Let’s say you have consecutive 5 parts of measurement. You note down each of their standards. Then you make a table for each of them. After that, you take 3 consecutive values from the dial indicator and find the average reading. And then we calculate the tolerance values as well.
Keep in mind that you have to pay attention to your document quality. You must make it more formal. By giving the date, you could track your dial indicator degradation factor. Besides, you could get an idea when should you substitute the dial indicator. You could also check your dial indicator after buying the products from the manufacturer.
Therefore, every time we measure using a dial indicator, we have to adjust our values with tolerance. This is the simplest way we can calibrate our dial indicator at home.
Calibration is not only useful for dial indicator but also useful to other precision instruments such as micrometer, dial caliper, etc. To get an accurate measurement, we have to examine our dial indicators first. After all, we have understood how important it is to calibrate the dial indicator. And we got an idea of how often we should calibrate the dial indicator.