In the Manage Measurement Task you can keep track of what measurements you are using in your modal analysis.

 

Definition of Measurement Project, Test Setup, Data Set and Channel

All measurements and information related to these are collected in a single project object called the Measurement Project item. As illustrated below there may be many measurements made when testing a structure. Normally, sensors are mounted to a structure and at least a single recording is made. We call such a recording a Data Set item that stores as many Channel items as there are sensors. The positions of the sensors are called a Test Setup item. In some cases it is necessary to move some of the sensors to new positions, keeping some in fixed references positions. Moving the sensors to a new position means that a new Test Setup item is created, and its recording is stored in a Data Set item.

 

Some times a recording will be repeated and you may not know which of the recordings to use in advance. You can then upload both recording and as such have multiple Data Sets associated with a Test Setup. However, before analysis you will need to make up your mind which of the Data Sets to use in the analysis, and then make sure the the particular Data Set is the active one.

The organization of the various items is as follows:

• Measurement Project Item (The one and only)
• • Test Setup Item 1 (First position of the sensors)
  • • Data Set Item 1 (First recording)
    • • Channel Item 1 (Sensor 1)
      • Channel Item 2 (Sensor 2)
    • Data Set Item 2 (Second recording)
    • • Channel Item 1 (Sensor 1)
      • Channel Item 2 (Sensor 2)
  • Test Setup Item 2 (Second position of the sensors)
  • • Data Set Item 1 (First recording)
    • • Channel Item 1 (Sensor 1)
      • Channel Item 2 (Sensor 2)

The Project Tree View 

The project tree view is the a tree view that visualizes the above organization in a simplified manner as it only show the channels of the active Data Set item of a Test Setup. In the tree view the channels therefore visually appear to hang on the leaves of the Test Setup items.

An example of the organization is shown below using the example data located in the folder Examples\HCTBuilding\ which comes from measurements performed by Professor Carlos Ventura from The University of British Columbia of the Heritage Court Tower building in Vancouver, see picture below.

The measurement campaign was divided into four Test Setups where each of them spanned a couple floors of the building. The first test setup is in the Project Tree View below termed Measurement 1 and the second Measurement 2, and so on. The sensors that are moved are Transducer 1, Transducer 2 and so on, and the sensors kept at the reference positions are called Ref. Transducer 1 and Ref. Transducer 2. The Channels Items of sensors being moved around are automatically colored green whereas the items of the reference sensors are colored blue. Any Test Setup or Channel item being disconnected in the analysis is colored red.

 

The Manage Measurements task is designed for the following:

• Organize the measurements into Test Setups and underlying Data Sets.
• Upload measurement files from various file formats and store then into Data Sets.
• Optionally merge uploaded measurements into an already created Data Set.
• View raw measurement time histories and optionally cut them into a new Data Set.
• Optionally differentiate or integrate measurements and store the results into a new Data Set.

The Manage Measurements Tutorial takes you through the basic steps of this task.