Reference Tables

Magnetic Extensometer Probe

This table contains standard information that is referenced by the other Magnetic Extensometer tables. It can be edited to suit the needs of an individual project and, if it is incorporated into your data template, the information will available in each new project file that is cloned from the new data template.
The Magnetic_Extensometer_Probe table is used to store the relevant details of each type of magnetic extensometer probe used to monitor the installation. The Description given to the Probe_ID can then be picked on the Magnetic_Extensometer_Set table.

Installation

Backfill

Define the backfill material and range in the Backfill table.

Magnetic Extensometer

The general magnetic extensometer installation details are entered on the Magnetic_Extensometer (upper) table. Select an available PointID and the reference point relative to which the magnet elevations are monitored from in Calculation_Method field. Enter the associated metadata in the Stickup_of_Ref_Point, Depth_Access_Tube and Remark fields as required.

The magnet number and the installation date must then be entered in the Magnet and the Date_Installed fields on the Magnetic_Extensometer (lower) table.
The Elevation Reference Point field is calculated by using the Elevation field value on the Point table plus the value of the Stickup_of_Ref_Point field.

Datum Elevation Reference Point

If the magnet elevations on the Magnetic_Extensometer_Set (lower) table are to be calculated from a fix reference point (e.g. from a magnet installed in a rock layer), then you should select the Datum option in the Calculation_Method field on the Magnetic_Extensometer (upper) table and the Datum_Magnet field of the corresponding magnet on the Magnetic_Extensometer (lower) table must be checked (as below).

Top Access Tube Elevation Reference Point

If the magnet elevations are to be calculated from the top of the access tube, the elevation level of which may change over the course of the monitoring period, then you should select the Top Access Tube option in the Calculation_Method field on the Magnetic_Extensometer (upper) table. A typical scenario where you would wish to select this option would be for a magnetic extensometer installation on a land reclamation project. If the Top Access Tube option has been selected in the Calculation_Method field, then Datum_Magnet fields on the Magnetic_Extensometer (lower) table must be unchecked.

If the Top Access Tube option in the Calculation_Method field on the Magnetic_Extensometer (upper) table is selected then the selected Monitoring_Point_ID on the Displacement (upper) table for the PointID must be Top Access Tube. The Type would be MSET. The survey data is then entered on the Displacement (lower) table.

By selecting the Top Access Tube option in the Calculation_Method field, the Elevation field value on the Magnetic_Extensometer Set (lower) table is calculated by using the Z field value on the Displacement (lower) table that was recorded at the most closely corresponding Date/Time to the monitoring result on the Magnetic_Extensometer_Set (upper) table for each magnet on the Magnetic_Extensometer_Set (lower) table.

Monitoring Readings

The general magnetic extensometer monitoring readings are recorded on the Magnetic_Extensometer_Set (upper) table by entering the date and time when the monitoring occurred in the Date Time field and the associated metadata in the remaining fields.
The reading for each magnet at the time when the monitoring occurred is recorded on the Magnetic_Extensometer_Set (lower) table by entering the recorded depth to each magnet in the Depth_Reference_Point field.
The Elevation field for that magnet is then calculated depending on the selected calculation method on the Magnetic_Extensometer (upper) table.
The Change_Elevation_From_Base and Change_Elevation_From_Previous field values are calculated based on the base field values on the Magnetic_Extensometer (lower) table.

Base Reading

If a recorded result is the base reading for that magnet, you can check the Base_Reading field to indicate this and the base reading will be displayed in the Elevation field on the Magnetic_Extensometer (lower) table. If you check more than one reading for each magnet as the base reading, then the value displayed in the Elevation field will be an average of the readings.

Adding an Additional Magnet

Additional magnets may be added as fill is added to a reclamation. This can be managed in the Tool by inserting a new record to the Magnetic_Extensometer (Lower) table, and assigning the next Magnet number and the Installation_Date. Then when you create a new set of readings the new magnet will appear in the list, and you should define the Base reading(s) for the magnet as described previously.

Output

Output Options

The Displacement_Minimum and Displacement_Maximum fields are used to determine the minimum and maximum settlement axis values for magnetic extensometer monitoring reports. The values entered into these fields override the values specified on the Monitoring_Project_Options table.
If a minimum and maximum value is not specified in Displacement_Minimum and Displacement_Maximum fields on the Magnetic_Extensometer table nor in the respective fields on the Monitoring_Project_Options table, then the minimum and maximum reading values recorded in Magnetic_Extensometer_Readings table are used to define the settlement axis extents on the reports.

In addition to the options mentioned above and in Monitoring Project Options table, you can select which of the monitoring results you do not want to display on the included log reports by checking the Do_Not_Report field on the Magnetic_Extensometer_Set table.

Output Reports

• Logs | MON MAGNETIC EXTENSOMETER INSTALL LOG
• Logs | MON MAGNETIC EXTENSOMETER SETT VS DEPTH
• Graphs | MON MAGNETIC EXTENSOMETER TIME PLOT
• Graphs | MON MAGNETIC EXTENSOMETER TIME PLOT COMP
• Graphic Text Docs | MON MAGNETIC EXTENSOMETER TABLE