# Measurement problems

**URL:** <https://discourse.slicer.org/t/measurement-problems/26907>\
**Category:** Support\
**Created:** [December 24, 2022, 5:15pm UTC](https://discourse.slicer.org/t/measurement-problems/26907 "2022-12-24T17:15:54Z")\
**Posts on this page:** 14\
**Page:** 1

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 24, 2022, 5:15pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/1 "2022-12-24T17:15:54Z")

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Operating system: Win 10  
Slicer version:5.2.1  
Expected behavior: measurement in millimetres  
Actual behavior: for some models gives a figure such as 6.0+04 for a measured value which must be circa 45 mm (eg max diameter of the acetabulum). The value if this is an exponent is quite impossible.

I can’ find any solution or explanation. Please help!

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [December 24, 2022, 5:19pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/2 "2022-12-24T17:19:17Z")

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You can increase the precision for length display in Units section in application settings.

Could you post a screenshot of how the unexpected value is displayed?

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 24, 2022, 5:22pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/3 "2022-12-24T17:22:35Z")

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Will do thankyou!

Robin

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 24, 2022, 5:47pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/4 "2022-12-24T17:47:02Z")

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![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/a/b/ab15c50f305e35a78d6de74143398b2fdf0a5730.png)

Thankyou Andras. Here is another example, The values given from length measurement do not seem to make sense even as exponentials.

Robin

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [December 24, 2022, 6:57pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/5 "2022-12-24T18:57:03Z")

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The values are 40mm and 200mm, which look reasonable. Increase the precision to make the values easier to read.

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 24, 2022, 7:03pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/6 "2022-12-24T19:03:02Z")

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I have done so and am getting consistent results now. Thank you very much for that.

Robin

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 28, 2022, 7:44pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/7 "2022-12-28T19:44:17Z")

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Does anyone know if the size of the length measurement/control point spheres can be reduced relative to the object being measured and if so how? I have not managed to find a way of doing so. I need to measure bone thicknesses of the ilium in different species and these can be quite small and the size of the spheres obstructs good measurement.

But I really do like 3DSlicer it is a powerful tool!

Many thanks

Robin Crompton

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [December 28, 2022, 8:13pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/8 "2022-12-28T20:13:30Z")

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Yes, in Slicer that’s called “glyph size” and can be expressed either in mm or as a percent of the display size.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/4/d/4d2c153288e8d26bcd737f1920468943898bedde.png)

Glad Slicer is working for you 👍

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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [December 28, 2022, 11:33pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/9 "2022-12-28T23:33:42Z")

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I would also recommend to switch to the “cross with a dot” glyph type for precise measurements. Note that if “absolute” button is not pressed then the glyph size is relative, so if you zoom in then the glyph does not occlude that much of the image anymore.

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 29, 2022, 8:08am UTC](https://discourse.slicer.org/t/measurement-problems/26907/10 "2022-12-29T08:08:46Z")

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Thankyou again!

Robin

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**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 29, 2022, 4:48pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/11 "2022-12-29T16:48:50Z")

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Please, I am sorry to be a nuisance but I can’t find where to do what you suggest, namely :

“I would also recommend to switch to the “cross with a dot” glyph type for precise measurements. Note that if “absolute” button is not pressed then the glyph size is relative, so if you zoom in then the glyph does not occlude that much of the image anymore.”

I should again be much obliged if you could tell me the procedure for doing what you suggest here!

Thanks so much in advance

Robin

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**Author:** ![jamesobutler](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jamesobutler/32/7511_2.png) [@jamesobutler](https://discourse.slicer.org/u/jamesobutler)\
**Post date:** [December 29, 2022, 5:38pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/12 "2022-12-29T17:38:07Z")

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See the Markups module documentation linked below. The Display section has an “Advanced” area which includes “Glyph Type”. There is an option to change it to “CrossDot2D”.

[https://slicer.readthedocs.io/en/latest/user\_guide/modules/markups.html#display-section](https://slicer.readthedocs.io/en/latest/user_guide/modules/markups.html#display-section)

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<div class="post-metadata">

**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [December 29, 2022, 5:51pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/13 "2022-12-29T17:51:31Z")

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Thankyou for such a quick response! The 2D cross glyph looks much better for accurate measurement.

Robin

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<div class="post-metadata">

**Author:** ![robin](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@robin](https://discourse.slicer.org/u/robin)\
**Post date:** [January 7, 2023, 3:38pm UTC](https://discourse.slicer.org/t/measurement-problems/26907/14 "2023-01-07T15:38:04Z")

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Can you actually section a model along a plane and make measurements especially thicknesses on the cutting plane? If so how?

Thanks very much

Robin