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08-30-2017
05:02 AM

08-30-2017
05:02 AM

I'm trying to create a calc where the answer is a design factor. The calc works fine when just using numbers, but when I try to use a value from earlier in the sheet I get the 'units are not compatible message'. Would appreciate any help on this, thanks.

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08-30-2017
05:47 AM

08-30-2017
05:47 AM

8 REPLIES 8

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08-30-2017
05:22 AM

08-30-2017
05:22 AM

Re: Units are not compatible

1.4 is a dimensionless quantity

a similar question

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08-30-2017
05:47 AM

08-30-2017
05:47 AM

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08-30-2017
06:00 AM

08-30-2017
06:00 AM

Re: Units are not compatible

This is the biiiiiiig old problem of "designed equations" from diverse textbooks or scriptums for example. A really big Problem

You have to check out first, which dimension the variable Df must have.

The parameter 1.4 must have the same unit like Df.

If 0.6 is a uitless factor then ok, but the 50 must have the unit of Unit(Tdt)*Unit(Df)²

Volker

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08-30-2017
06:12 AM

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08-30-2017
06:13 AM

08-30-2017
06:13 AM

Re: Units are not compatible

@vlehner wrote:

This is the biiiiiiig old problem of "designed equations" from diverse textbooks or scriptums for example. A really big Problem

You have to check out first, which dimension the variable Df must have.

The parameter 1.4 must have the same unit like Df.

If 0.6 is a uitless factor then ok, but the 50 must have the unit of Unit(Tdt)*Unit(Df)²

True. But, in my experience, design factors are usually dimensionless.

Alan

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08-30-2017
06:21 AM

08-30-2017
06:21 AM

Re: Units are not compatible

Thanks everyone, I've got it working now. All the replies are appreciated 🙂

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08-30-2017
07:20 AM

08-30-2017
07:20 AM

Re: Units are not compatible

@AlanStevens wrote:

True. But, in my experience, design factors are usually dimensionless.

Alan

Many of these "design factors" are unit conversions

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08-30-2017
07:56 AM

08-30-2017
07:56 AM

Re: Units are not compatible

@Fred_Kohlhepp wrote:

@AlanStevens wrote:

True. But, in my experience, design factors are usually dimensionless.

Alan

Many of these "design factors" are unit conversions

Yes, though these are usually supplied as single numbers rather than expressions that require evaluating, are they not?

Alan