Points / Calibration List

Introduction

Clicking on the Points / Calibration List menu displays the Calibration List page. A new NovaStar system will display an empty Calibration List.

A calibration is a set of values that is applied to incoming raw data reports to produce calibrated data in the desired engineering units. NovaStar saves calibration values in a database table that can be viewed using the Calibration List menu. The Calibration List page shows all of the calibrations that have been assigned to points defined in the NovaStar system.

Calibration List (see full-size image)

Data calibrations may have to change over time if sensing equipment is moved or replaced. Creating a new calibration, rather than editing an existing calibration, is an important distinction in order to maintain historical accuracy. When Add or Edit are selected on a data calibration, NovaStar records the time associated with the creation of the new calibration and it becomes the calibration applied to incoming data streams. The Calibration List table shows all of the data calibrations that have been applied to data at each point over time. Sometimes a data calibration change may be applied retroactively to a period of data reports that were calibrated erroneously when initially received.

Click the Add button at the upper right-hand corner of the Calibration List table to create a new calibration. Or, click the Edit button associated with an existing calibration to use that calibration as a copy template for creating a new calibration.

Calibration List

The following image illustrates the Points / Calibration List page after a calibration has been selected in the list at the top of the page.

Calibration List (see full-size image)

Navigation, Adding, Deleting, Modifying, and Copying Calibrations

See Application Functionality for more information about basic component functionality.

The Calibration List page conforms to a layout similar to many data types which includes a list of data items. See List Features for more information detailing page navigation; adding, copying and deleting calibrations; and modifying existing calibrations.

Adding a new calibration

Note that creating a new calibration requires entering the point, multiply value, added, base value and time.

Data reported by station sensors is raw data. This data needs to be converted into engineering units using appropriate calibration values. The calibrated data is displayed in reports and used in data analysis. Raw data is calibrated using the calibration equation:

Cal data = Raw data * Multiplier + Base value

Identification

The following calibration properties are used to identify the calibration.

Calibration Identification (see full-size image)

Data Label	Description
Point:	Select a point for calibration from the pick list.
Multiply value	Multiplier term (slope) in the calibration equation.
Adder	Adder term (offset) in the calibration equation.
Base value	Base value term (elevation) in the calibration equation.
Time	Date and time when calibration becomes effective. Point calibrations can change over time due to sensor drift, replacement, or relocation. NovaStar keeps a time history of point calibrations in the data base. A point calibrations remains in effect from the effective time forward until another calibrations is added with a newer effective time. The button assigns the current date and time.

Calibration Recalibration

If a calibration is changed for data reports already stored in the database then the calibrated data values must be recalibrated. The Calibration Recalibration tool will recalibration point data reports for a selected time period.

Calibration Recalibration (see full-size image)

Data Label	Description
Starting Time	Select the starting time for the recalibration. Click to set the starting time to the calibration effective time. Note: the starting time must before the ending time.
Ending Time	Select the ending time for the recalibration.
Action	recompute will recalibrate the data reports for the assigned calibration records. set will assign the selected calibration and then recalibrate the data reports.
Quiet	false prints the command activity in the display window; true only prints the command start and stop messages. Use true for the fastest command performance.
Validate	recompute will revalidate the data reports after the recalibration. false will not perform the revalidation.
Rating	recompute will recompute the data reports ratings the recalibration. false will not perform the rating recomputation.

Calibration Delete

To delete a calibration from the Calibration List, select the calibration, click Edit and then click Delete. The page prompts again with a popup to confirm the deletion. If a calibration is deleted, the record of that calibration will be deleted, which describes how calibrated data records were computed for the period of time during which that calibration was in effect. Deleting the calibration will not, however, alter the data records that were computed using that calibration.