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How can I make mathcad prime use different base units in calculations?

TS_9501702
4-Participant

How can I make mathcad prime use different base units in calculations?

So my starting parameters are P1= 7.5 kW and n1= 750 rpm.

 

On the left side Mathcad is converting my units to SI which messes with my final results.

 

For this formula I have to use P1 in kW and n in rpm, which mathcad is changing into W and revolution per second. Right side is how to calculation is supposed to be going by the formula.

 

Is there a way I can fix this? I saw that in Mathcad 15 you could define a custom unit system. Is there anything like that for Mathcad Prime? 

Thank you!

TS_9501702_0-1634646642705.png

 

 

 

 

 

1 ACCEPTED SOLUTION

Accepted Solutions

The formula you use has built-in correction factors (60/(2 pi) and 10^6) which are not necessary if you use units in Prime:

Werner_E_0-1634650751360.png

 

View solution in original post

4 REPLIES 4
LucMeekes
23-Emerald I
(To:TS_9501702)

There is no custom unit feature in Prime. You're not the first to ask for/about it, and probably will not be the last.

 

So you've changed the unit of the Moment Mt1 from J to N*mm.

You should do the same with the P and the rotations: type a k before the W, and replace 1/s with rpm.

 

Success!

Luc

 

 

TS_9501702
4-Participant
(To:LucMeekes)

That one doesn't work. That is the point of the post 😄 I need Mathcad to use kW as base units

The formula you use has built-in correction factors (60/(2 pi) and 10^6) which are not necessary if you use units in Prime:

Werner_E_0-1634650751360.png

 

View solution in original post

StuartBruff
22-Sapphire II
(To:TS_9501702)


@TS_9501702 wrote:

So my starting parameters are P1= 7.5 kW and n1= 750 rpm.

 

On the left side Mathcad is converting my units to SI which messes with my final results.

 

For this formula I have to use P1 in kW and n in rpm, which mathcad is changing into W and revolution per second. Right side is how to calculation is supposed to be going by the formula.

 

Is there a way I can fix this? I saw that in Mathcad 15 you could define a custom unit system. Is there anything like that for Mathcad Prime? 

Thank you!

TS_9501702_0-1634646642705.png


Mathcad hasn't really messed with your units.  You need to tell it (effectively) that your base unit of time is the minute,  

 

2021 10 19 B.png 

 

or, more specifically, ...

 

2021 10 19 C.png

 

Stuart

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