Seal Groove & Fine Channel Measurement with OMM Vision Measuring Machine

The sealing reliability of a liquid-cooling system determines whether coolant leaks and whether the system runs stably over time. Groove width, groove depth, bottom radius and sidewall straightness are the core geometric parameters that decide whether an O-ring compresses correctly and forms a reliable seal. The SIG Vision Measuring Machine provides a non-contact, quantifiable Video measuring system for the precision inspection of seal grooves and fine channels.

Optical Principle for Groove Measurement

An OMM (Optical Measuring Machine) uses a high-resolution industrial camera and a telecentric optical system to capture the surface contour of the workpiece, then combines image processing with geometric computation to complete measurement without touching the part.

For groove-type features, a Vision Measuring Machine offers three decisive strengths:

• Non-contact measurement — no probe can scratch or deform a narrow, delicate groove.
• High-resolution imaging — the groove bottom, sidewalls and transition radius are rendered in clear detail.
• Profile analysis — the software evaluates groove width, depth, sidewall straightness, bottom radius and parallelism simultaneously.

The SIG Video measuring machine is built on a high-precision granite base and column, and is equipped with programmable surface and transmitted illumination to guarantee stability and imaging quality throughout the measurement cycle.

Why Seal Grooves Are Hard to Measure

Seal grooves and fine channels in liquid-cooling parts present several specific challenges:

• Narrow space — seal grooves are typically 1 mm to 5 mm wide, and miniature grooves can be under 1 mm, beyond the reach of conventional callipers and depth gauges.
• Strict bottom-radius requirement — the transition radius at the groove bottom directly affects the stress state of the seal; a wrong radius can cause local stress concentration or insufficient sealing.
• Sidewall perpendicularity and straightness — tilted or wavy sidewalls prevent the seal from compressing uniformly, creating a leakage risk.
• Reflective materials — liquid-cooling parts are mostly aluminium alloy or copper; their machined surfaces are highly reflective, which can destabilise edge detection on ordinary optical equipment.

The SIG Groove-Inspection Solution

The SIG Vision Measuring Machine addresses these needs with five core functions:

1. Groove Width and Depth

A high-magnification lens captures the groove cross-section; the software identifies both side edges and computes width. Through Z-axis focusing with glass-scale feedback, groove depth is measured with micron accuracy. For shallow seal grooves, the non-contact approach avoids the problems of a probe that cannot reach the bottom or that deforms the part under measuring force.

2. Bottom Radius

An arc-fitting algorithm automatically extracts the transition radius at the groove bottom. This is essential for assessing seal stress: too small a radius risks cutting the O-ring, while too large a radius reduces effective compression.

3. Sidewall Straightness and Parallelism

By scanning continuously along the groove, the system collects multi-point data on each sidewall and computes straightness as well as the parallelism between the two walls. Straightness deviation often indicates tool vibration or a feed-path offset during machining.

4. Profile Comparison

The measured profile can be superimposed on the design drawing to visualise the deviation distribution along the groove. For profiled or asymmetric seal grooves, this function rapidly locates defective regions.

5. Anti-Reflection Programmable Lighting

A multi-channel combination of programmable ring and coaxial light adapts to the material and surface condition, suppressing glare-induced edge errors on reflective metals.

Typical Applications

In the inspection of liquid-cooling fittings and manifolds, seal-groove width and depth, bottom radius and end-face parallelism are the key quality-control items. The SIG OMM completes all geometric parameters in one pass, sharply reducing per-piece cycle time, and automatically generates an inspection report with every value archived for traceability.

On cold-plate sealing faces, the system scans continuously along the seal groove, capturing width, depth, sidewall straightness and bottom radius as a complete data set, reconstructing the true geometry of the channel in full.

Summary

The machining accuracy of seal grooves and fine channels directly determines the sealing reliability and long-term stability of a liquid-cooling system. As a non-contact, high-precision Video measuring system, the SIG Vision Measuring Machine delivers systematic Geometric Dimension Measurement for groove width, depth, bottom radius and sidewall straightness, helping liquid-cooling manufacturers hold the last line of defence against leakage.