Plugin: Basic Reference Data Module
The measurement units can be used in the definition of scales.
Open the Measurement Scales browser by selecting the Measurement Scales icon on the Reference Data tab. Measurement Scales are given with a Short Name, a Name, Type, Number Set, Unit and Container RDL. Measurement Scales can be of the following types1:
Defined by Factor, a Logarith Base and Exponent. Further defined by Reference Quantity Kind and an optional Reference Quantity Value
Example1: The base 10 logarithmic measurement scale for "sound pressure level" in "decibel", with factor is "10", exponent is "2", referenceQuantityKind is "sound pressure" and referenceQuantityValue.value is "20" on the "μPa" RatioScale. Source: ISO 80000-08
Cyclic ratio scale:
Measurements bound to a range and repeat (degrees in a circle, time periods).
Example1: Planar angle with modulus 360 degree, therefore an angle of 450 degree is the same as an angle of 90 degree, and -60 degree is the same as 300 degree.
Relative scale with arbitrary 0-point (e.g. Celsius-scale).
Example1: The Celsius and Fahrenheit temperature scales are common examples of interval scales
Describes order, but not relative size or degree of difference between the items measured (e.g. rank order).
Examples1: The Beaufort wind force scale with ScaleValueDefinitions (as defined by the World Meteorological Organization): 0 : "Calm"; 1 : "Light air"; 2: "Light breeze"; 3: "Gentle breeze"; 4: "Moderate breeze"; 5: "Fresh breeze"; 6: "Strong breeze"; 7: "Near gale"; 8: "Gale"; 9: "Strong gale"; 10: "Storm"; 11: "Violent storm"; 12: "Hurricane".
The NASA/ESA Technology Readiness Level (TRL) scale with ScaleValueDefinitions: 1 : "Basic principles observed and reported"; 2 : "Technology concept and/or application formulated"; 3 : "Analytical and experimental critical function and/or characteristic proof-of- concept"; 4 : "Component and/or breadboard validation in laboratory environment"; 5 : "Component and/or breadboard validation in relevant environment"; 6 : "System/subsystem model or prototype demonstration in a relevant environment (ground or space)"; 7 : "System prototype demonstration in a space environment"; 8 : "Actual system completed and 'flight qualified' through test and demonstration (ground or space)"; 9 : "Actual system 'flight proven' through successful mission operations".
Interval scale with a true zero point (e.g. mass, length, Kelvin-scale temperature).
Example1: The majority of the physical quantities are expressed on ratio scales, e.g.: length (metre, millimetre, kilometre, inch, foot, mile, lightyear); mass (kilogram, gram, nanogram, ton, pound); time (second, hour)
For these categories of scales, the scale indicates the step size between measurement units. A choice of number steps can be made by choosing a different number set. The number sets available are:
Persons with a role that has the permission Modify on the ClassKind Site Reference Data Library are able to access the Basic RDL to create, edit or delete measurement scales.
A description of the available functionalities is given below. Next to these it is possible to use the generic functionality using the Search and Help icons. To make sure the latest data is shown in the browser, it is always possible to refresh it using the Refresh icon. The measurement scale modal dialogs further have the generic functionality on the Aliases, Definitions and HyperLinks tabs, described in the topic standard tabs.
To create a new measurement scale, select the Create Measurement Scale icon or in the context menu select Create a Scale for each of the available types.
On the Basic tab, provide the mandatory fields for Name and Short Name. Furthermore, it is required to provide the Container RDL, see the management and usage of RDLs. On the Basic tab, select the applicable measurement unit for which the corresponding scale has to be created. For any type of measurement scale, a Number Set has to be selected as well.
Optionally, in defining a scale, it is also possible to define conditions for the allowed values. It is possible to supply a Maximum and/or Minimum Permissible Value, together with an explanation for this in the Positive and/or Negative Value Connotation. Tick the check box to include this minimum or maximum value.
On the Value Definitions tab, it is possible to add a definitions for values that have a special significance for the measurement scale. To do this, select the Create Value Definition icon and provide the Name, Short Name and Value. All further functionalities for Edit, Inspect, Delete and a link to the Help are available as well. The Create, Edit or Inspect Scale Value Definition modal dialogs further have the generic functionality on the Aliases, Definitions and HyperLinks tabs, described in the topic standard tabs.
For an Interval and a Ratio Scale, these are all the fields. Further provide the additional required fields for the other types:
For a logarithmic scale
On the Logarithm tab, provide the Logarithm Base, Exponent, Reference Quantity Kind and Reference Quantity Value
For a cyclic ratio scale
On the Basic tab, provide a value for the Modulus that represents the repeat cycle for the cyclic ratio scale.
For an ordinal scale
On the Value Definitions tab, select the Create Value Definition icon and provide the Name, Short Name and Value. The created value definitions will be presented as possible values for parameter types that are using this ordinal scale. These parameter types should then be created as a Quantity Kind parameter type.
explain link to/ difference with enumeration parameter type as alternative approach?
After providing the required details, click Ok to create the Measurement Scale.
To edit a measurement scale, select the Edit Measurement Scale icon or in the context menu select Edit. Depending on the type of measurement scale, it is possible to edit all the available fields on the Basic or content-specific tabs, as well as optional items on the other tabs for Aliases, Definitions, and Hyperlinks.
After making the required changes, click Ok.
Please note that editing measurement scales should be handled with extreme care, as this will have a large impact on all engineering models that use concepts that depend on it. It is advisable to only edit measurement scales to fix apparent mistakes.
The browsers in the CDP™ Client of the user that performed the editing action will be updated immediately. Other CDP™ Clients will be updated with a [refresh][Refresh].
On the Advanced tab, a Revision Number is given; see the description of Revision Number for details.
To inspect a measurement scale, select the Inspect Measurement Scale icon or in the context menu select Inspect. In the Inspect modal dialog, all the details can be seen on the Basic or content-specific tabs, as well as optional tabs for Aliases, Definitions, and Hyperlinks. Additionally the status of the measurement scale is given by the check box for Deprecated, see the description of Delete below.
The Advanced tab provides information that may be useful mostly to CDP™ database administrators. Given are the UniqueID and the Revision Number, see the description of Revision Number for details.
A measurement scale should not be deleted from the CDP™.
To delete a measurement scale, select the Delete Measurement Scale icon or in the context menu select Delete. Items from the CDP™ are never completely deleted, but they are marked as Deprecated. This Deprecated status is an indication to users that it should not be used anymore.
To export measurement scales, select the Export Measurement Scales icon or in the context menu select Export.
Last modified 4 years ago.