Measurement Stability Tracker

Table of Contents

What is the Stability Tracker?

The Stability Tracker monitors your gauge's check-standard readings over time using an Individual-Moving Range (XmR) control chart. It detects drift, sudden shifts, or increasing variation before the next calibration is due.

1Setup

Enter your gauge information and check standard parameters. You can link a gauge from your Gauge List or enter details manually.

Gauge Name -- A descriptive name for the gauge being tracked.
Nominal Value -- The known value of the check standard used for verification readings.
Tolerance -- Optional. When provided, tolerance lines appear on the chart for visual reference.

Tip

Linked mode: If you select a gauge from your Gauge List, the setup form auto-fills with the gauge's metadata.

2Data Entry

Enter date and measurement pairs for your check-standard readings. Each row represents one verification reading taken at a specific date.

At least 10 readings are recommended for reliable XmR control limits.
Use the Exclude checkbox to remove known bad readings from control limit calculations.

3Analysis

The tool computes XmR control limits, plots the Individual chart and Moving Range chart, and evaluates Western Electric rules to detect out-of-control conditions. A stability verdict is shown based on the analysis.

Understanding Stability Verdicts

Stable No rule violations detected. All readings are within control limits. The gauge is performing consistently.

Warning Minor rule violations detected (Rules 2-8) such as runs or trends, but no points beyond 3-sigma. Monitor closely.

Unstable Points beyond control limits or multiple concurrent rule violations. Consider recalibrating the gauge before its scheduled due date.

Insufficient Data Fewer than 10 readings. Add more check-standard measurements for a reliable assessment.

4View & Export

Review the full results summary, download a PDF report, share the results link, or get AI coaching to help interpret the analysis.

Tip:

Add new readings over time and re-save to track your gauge's long-term stability. Each save creates a new version with a link to the previous one.

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