How can recurring measurements be monitored and evaluated in SONAPHONE DataSuite using key metrics, reference measurements, and thresholds?

For recurring condition measurements, the development of a measurement value over time is often more important than an individual measurement.

SONAPHONE DataSuite supports trend monitoring using:

• key metrics,
• reference measurements,
• a command variable,
• warning and alert limits,
• graphical trend displays.

This makes it possible to monitor changes at a measuring point across multiple inspections.

What are key metrics?

Relevant measured quantities can be defined as key metrics for a measuring point.

Depending on the respective measurement, different level values and other measured quantities can be used for evaluation.

Up to eight key metrics can be selected for display in AssetData diagrams.

The selection can be configured individually for each measuring point.

What is the command variable?

One of the defined key metrics can be selected as the command variable.

The command variable is the measured quantity for which the condition thresholds of the measuring point are defined.

Two thresholds can be specified:

• warning limit
• alert limit

The thresholds are stored for the respective measuring point and can be adjusted if required.

Are there universal warning and alert limits?

No. DataSuite provides the option to define thresholds for a measuring point but does not specify universal limit values for all machines or applications.

Suitable thresholds must be defined according to the respective application, test object, and known operating conditions.

What is a reference measurement?

An existing measurement can be defined as a reference measurement in AssetData.

It can be used to compare current measurement values with a known operating condition.

A reference measurement may, for example, represent:

• a newly installed machine,
• the condition after repair or maintenance,
• a known good operating condition.

The reference measurement is identified in the trend diagram and can be changed if required.

What does the trend diagram show?

The Trending widget in AssetData displays the development of the selected measurement values and key metrics over time.

It can therefore be used to identify:

• long-term changes,
• gradual increases in measured levels,
• changes compared with the reference measurement,
• values approaching warning or alert limits.

For the command variable, the defined thresholds are taken into account in the trend display.

The displayed time period can be adjusted to analyze either long-term development or individual periods in more detail.

Why are trends often more meaningful than individual measurements?

The absolute measurement value of a test object can be influenced by many factors, including:

• design and construction,
• rotational speed,
• load,
• process condition,
• measurement point,
• sensor and coupling.

For machine and bearing monitoring in particular, it is therefore useful to compare the same measuring point over time under conditions that are as similar as possible.

A continuous change from the previous condition may be more significant than a single absolute measurement value.

Can actions be derived from trend analysis?

Yes. Based on the evaluated measurement data, DataSuite allows users to:

• adjust the command variable and thresholds,
• adjust the measurement cycle,
• define maintenance actions.

Trend analysis therefore supports condition-based planning of maintenance activities.

Technical interpretation of the measurement values and the definition of appropriate thresholds and actions remain the responsibility of the user.