Let’s say you are looking for a measuring instrument to measure some geometrical tolerances in order to make your product more expecting and accurate. Yes, the dial indicator can help you to go through this.
But which one to choose? On the web, you’ll see a few platforms mentioned that if the dial indicator and dial test indicator are similar instruments. Although both of them measure the tolerances, they have some differences. What are the differences between the dial indicator from the test indicator?
In terms of similarities, the dial Indicator and test indicator are pretty the same in terms of their working principle. According to the definition, it’s known that an instrument with a dialing display that measures the geometrical tolerance from objects is known as a dial indicator.
Since the dial indicator varies, we will be explaining just the main types; the dial indicator and test indicator. Actually, they can be dial plunger indicator, dial digital indicator, dial indicator with magnetic base, dial test indicator, dial test digital display indicator, dial test with magnetic base indicator, etc.
Before you go to the explanation, you could have a glance at the following summary of the differences between these two indicators. It’s important to give a quick overall idea.
|Summary Table of Dial Indicator Vs Dial Test Indicator|
|Key points||Dial Indicator||Dial Test Indicator|
|Contact Type||Plunger Type||Lever Type|
|Size & Weight||Bigger and Heavier||Smaller and lighter|
|Repetitive and comparative||Consistency measurement|
|Vertical||Vertical, Horizontal or angular excel|
|Tolerance Type||Flatness, run-out, roundness||one- or two-dimensional tolerances flatness,
run-out, roundness, cylindricity, etc
|Visibility||Clear vision||Smaller dial display troubles with the visibility|
|Lower resolution and accuracy
0.001″ to 0.0001″
|Higher resolution and accuracy
0.0001″ to 0.00005″
|Bigger range, 0-12″||smaller range 0.015″ to 0.06″|
|Rotation||Both clockwise and anticlockwise||Clockwise rotation only|
|Uses||Specifically used||Very often used|
Dial Indicator Vs Dial Test Indicator: 9 Differences
The following are the main key points with the explanations.
1. Contact Point
The dial indicator is a plunger-type contact pointed instrument. The plunger contact point can be divided into a few types such as shell, 60˚ conical, spherical, needle, flat carbide tip contact points. Here are some examples of them in the picture.
In comparison, the test indicator is a lever-type contact pointed instrument. The lever-type contacted point has a ball structure on the top of the stem. It can take the readings at a multi-directional position.
2. Size and Structure
In terms of size, dial Indicators are normally bigger. According to their structure, dial indicators are heavier than the dial test indicator. Let’s see an example of a Mitutoyo company product. We took the Mitutoyo dial indicator series 2 to observe the general structure and size of it. This model is around 113 mm of height and 38 mm of width. The components are the dialing display of two kinds such as a balanced scale, a continuous balanced scale, etc.
Dial test indicators are normally smaller in size. They are not as heavy as dial indicators. Let’s see an example of Mitutoyo company products. We took a Mitutoyo dial test indicator series 513 to observe the general structure and size of it. This DTI is around 90 mm of the length and 13mm of the height.
3. Measurement Type
When it comes to measuring, the dial indicator excels in repetitive and comparative measurements. From two or three measurements we can judge the average value of tolerance. For this reason, we need a repeat of taking the measurement and compare the values with each other.
Dial test indicator excels in a consistency measurement. According to the definition from instrumental education, the values which need not measure continuously to find a comparative value is known as consistency measurement. In simple words, a consistency measurement doesn’t require a comparative or repetitive solution to measure value.
4. Excelling Position
It’s required to be in a vertical position for a dial indicator to excel in its measurement. It means when mounted on a fixture gage, the dial indicator must be straight and vertical with the horizontal surface. While taking the reading it comes to its original position all the time. It can only be used for one-dimensional measurements.
Compared to the test indicator, you could place it on any geometrical axis. It can be placed both vertically or horizontally with the measuring surface. It can also be measured with an angle from the surface. But for the angular position, different models require different angular positions. For example, some models are manufactured where a 30˚ angle with a surface is mandatory while taking the readings. So, this dial test indicator can be used in one- or two-dimensional measurements.
A dial indicator is normally a fixed instrument. It has a fixed shape always. Its structure cannot be changed for reading tolerance. Other than the screws and dialing display, the dial indicator has only one position to read the value.
Dial test indicator is a flexible instrument which means it has a different form of the position. The stem of the DTI has a spring attached to due to the angular thrust from outside. So, it moves with the force exerted from the outside.
6. Visibility and Accessibility
Dial indicators have a bigger dial display than the DTI. There are various kinds of dialing display for Dial Indicator. Such as Balanced dial display, continuous Dial display, etc. So due to its bigger size, Dial indicators are more clearly visible than the Dial test indicator. Accessibility of the dial test indicator is not much as a dial test indicator. Because it can be used in specific measurements and uses are limited.
Dial test indicators have a comparatively smaller dialing display due to its smaller structure. So, the visibility is not as good as the dial indicator. But It has a good accessibility feature. As it can be used in different positions, so it can be used in many measurements. And thus, the accessibility proves an upside from the dial indicator.
7. Resolution and Accuracy
Dial indicators have lower resolution and accuracy than that of the dial test indicator. Normally the range is from 0.001″ to 0.0005″. So, its accuracy is also lower than that of the dial test indicator.
Dial test indicator has a higher resolution and accuracy. The resolution range is from 0.0001″ to 0.00005″. So, the dial test indicators are more accurate than that of the dial indicators.
8. Measurement range
Dial indicators have a bigger measurement range, starting from 0 inches to 12 inches. It’s an upside using a dial indicator. Why? Because sometimes we may exceed the tolerance value due to the construction requirements. So, a dial indicator can be used to do that as it can be measured in the long-range of the measurement.
Dial test indicators have a lower range of measuring range, is normally used for the most accurate manufacturing. The measuring range is from 0.015″- 0.060″.
9. Rotational direction
Dial indicators can be used to measure in both clockwise and anti-clockwise direction. In this case, this feature is considered as the upside of the dial indicators for the users.
On the other hand, the dial test indicator can’t be used to measure in an anti-clockwise direction as they are designed so. This difference is easy to spot.
Dial Indicator Vs Test Indicator: Similarities
Dial indicators and dial test indicators are pretty distinct from each other, but yet there have few similarities in them. The following listed points are the similarities that can be found in both of them.
- Both the dial Indicator and the dial test indicator can be used in measuring geometrical tolerance.
- They can be used in different tolerance factors such as run-out, total run-out, cylindricity, perpendicularity, flatness, roundness, straightness, etc.
- Both of the products can be delivered with a strong magnetic base stand.
Another nice point to take into account is the companies that manufacture these precision measuring tools. Dial Indicators and Dial test indicators both have the same manufacturing companies such as Mitutoyo, Starrett, Mahr, Accusize, and so on. They are now dominating the market for the current age.
Overall, we hope that you could easily learn the differences between the dial indicator and the dial test indicator through this page. In addition, we hope you have read their similarities as well.
As a piece of extra information for you, in case you are looking for a dial indicator on the market, we suggest you read our article on “The Top 10 Best Dial Indicator” and if you are looking for a test indicator, we recommend you to read “The Top 10 Best Test Indicator”. Even further, you could also read our article about the best dial indicator with a magnetic base and about the best digital display dial indicator.