What is line standard and end standard?
Choosing the right measuring device is vital for accurate measurements. There are two primary distance measurement methods: line standards and line measurement.
What are Line Standards?
Line standards, like the division-marked meter rule, involve directly comparing lengths between engraved lines without auxiliary devices.
What are End Standards?
Using the distance between two parallel surfaces as the measurement standard is referred to as end standard or end measurement. This method, commonly used in precision workshops, employs tools like end bars, micrometer anvils, and slip gauges.
These tools have hardened end surfaces to resist wear and ensure measurement accuracy. A comparator is utilized to accurately transfer the line standard to the end standard. Compared to line standards, end standards yield higher accuracy results.
Pros and Cons of line standard
| Pro’s | Con’s |
|---|---|
| Quick and easy to handle, applicable over a wide range. | Lacks a built-in datum, making alignment with the measurement axis challenging. |
| Scale markings, not leading ends, are resistant to wear. | Engraved lines’ thickness is not considered, hindering high-accuracy measurements. |
| Magnifying tool may be needed for close tolerance length measurement. | |
| Parallax effect on scales can lead to both positive and negative reading errors. |
Pros and Cons of End standard
| Pro’s | Con’s |
|---|---|
| Offers highly accurate readings compared to line standards. | Time-consuming as only one measurement at a time is possible. |
| Ideal for close tolerance measurements. | Measuring faces are susceptible to wear. |
| Flat and parallel measuring faces provide a built-in datum, facilitating easy alignment. | |
| No parallax error at the end of the standard. | |
| Achieves dimensional tolerances as close as 0.0005mm. |
