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Catching Errors through Mathcad Units

mzeftel
1-Newbie

Catching Errors through Mathcad Units

Units are one of Mathcad’s most useful features. Mathcad provides the ability  to track and balance units, helping you avoid costly and even dangerous  mistakes. You can easily convert between multiple unit systems by just typing in  a unit from another system as shown below:


Mathcad’s default unit system is SI (International System of Units). Because  Mathcad balances units, you can use Mathcad for dimensional analysis, and catch  errors in your work. Mathcad double-checks to make sure you type in an equation  correctly, use a correct formula, and insert the correct units.

A crane picks up a 25 kg beam off the ground and puts it on 36 foot wall. How  much work did the crane do?


Mathcad equations

Mathcad also combines units into simpler units for you, unless you turn it  off. Look at the result below, when simplify units are turned off.


Mathcad equations

Suppose instead of energy you asked for the result in units of force.


Mathcad equations

Mathcad shows your error by balancing the units and giving you an extra m for  meters. To correct the error, you try force per length, which still has leftover  units.

Mathcad equations

Finally you put in a different unit of energy and the equation has no  leftover units.


Mathcad equation

Customizing Units


Barrels of Oil

Mathcad has many units, but you can easily define  custom units, if you need to.

One unit that Mathcad doesn’t include is barrels of oil. In the United States  bbl stands for one barrel of 42 US gallons of oil.


Mathcad equations

The volume of 5 barrels of oil is 795 liters.

In the upcoming release of Mathcad Prime 1.0, you’ll see how we’ve expanded  units throughout Mathcad, adding them to almost all functions, and adding mixed  units to matrices, vectors, solve blocks, and plots. We’re also returning to  dynamic units, at the request of many users.

Take advantage of all Mathcad has to offer in the way of units, always using  them to check your calculations.

Mona Zeftel
Mathcad Senior Technical Consultant

2 REPLIES 2
PhilipOakley
5-Regular Member
(To:mzeftel)

I can't see any of the pictures in this thread from my corporate internet access. Can you ensure that the pictures are accessible.

I also get a warning message that there are some secure and some insecure parts of this web page. The web page should not cause this. Either be secure, or be open. Don't mix the types within the page. Switching off a securinty warning should not be the default user response!

Philip

I would like to know if there is any possiblity make/swich on/off a particular set of units for a particular project. For instance I work a lot with moments of resistance (mm3, but not kubic mm - this is not a problem) and I get automatic L (for liters). Liters is in fact not a SI-unit. Can I switch off L for liters only? Or is there any other solution to this habit other than not using the unit feature?

Abraham 

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