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O
ojoshi-21-Visitor
1-Visitor
January 13, 2014
Solved

Precision

  • January 13, 2014
  • 3 replies
  • 1901 views

Hi

I have revently starting using Mathcad and am a bit novice in it.

I have a simple query regarding precision. Have a look at the image:

mathcad.png

Apparently beta being of the order of 10e-4 is rounded to zero and hence the calculation gives wrong result. Can someone please help me understand where I can make Mathcad calculate in larger precision but display in 3 decimals? Just like excel!

Thanks

Omkar

Best answer by AndyWesterman

An on-going issue with the entry of temperature units.

Capture.PNG

1°C gives 274K and the wrong answer for the first vaue of beta.

either 1K or 1delta °C should give the correct answer as in the attached

Regards

Andy

3 replies

A
AlanStevens19-Tanzanite
19-Tanzanite
January 13, 2014

You've used the °C function. This converts Celsius to K, so 1°C is 274.15K, so it's actually dividing beta by 274.15. You want beta to be per unit degree C, which is the same as per unit K, so just replace the denominator of beta with 1K.

Alan

A
AndyWesterman12-AmethystAnswer
12-Amethyst
January 13, 2014

An on-going issue with the entry of temperature units.

Capture.PNG

1°C gives 274K and the wrong answer for the first vaue of beta.

either 1K or 1delta °C should give the correct answer as in the attached

Regards

Andy

W
Werner_E25-Diamond I
25-Diamond I
January 13, 2014

Its not a matter of precision. Its because the difference of Temperatures can be quite tricky because Mathcad converts all Tempereatures tu Kelvin. Thats the reason why mathcad offers the Delta°C "unit".

13.01.png

Similarily you run into problems by division using other temp units than Kelvin

13.01.png

Here is a ways to get your 1.018:

13.01.png

O
ojoshi-21-VisitorAuthor
1-Visitor
January 13, 2014

Thanks guys, guess this was a classic rookie mistake! Easiest trick seems to be to use delta deg celius.

Cheers

Omkar

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