Granite Air-Bearing Guideway Inspection: What Should an Acceptance Report Include?

A granite air-bearing guideway inspection report should do more than state that a component has “passed.”

It should identify the part, define the inspected features, record the measurement conditions, show the results against agreed acceptance limits, and make the scope of the inspection clear.

Most importantly, it should distinguish the geometry of the granite component from the performance of a complete air-bearing motion system.

ZHHIMG®’s published guidance separates acceptance into granite component inspection, mechanical assembly checks, and complete-system verification. This distinction helps buyers define what a supplier’s report does—and does not—demonstrate.

This article explains what to include in an acceptance report and what to agree with your supplier before production begins.

Quick Checklist: Essential Report Contents

The exact requirements depend on the drawing and supply scope, but the following checklist provides a useful starting point.

ZHHIMG’s existing guideway purchasing guidance identifies these elements—including measurement locations, support conditions, instrument identification, and uncertainty where required—as items to agree before ordering.

1. Define What Is Being Accepted

Before reviewing any numerical results, confirm what the supplier is delivering.

“Granite air-bearing guideway” may refer to different supply scopes:

• A finished granite guideway component.
• A granite base with several functional guide surfaces.
• A mechanically assembled structure.
• A matched guideway and carriage assembly.
• A complete motion system with bearings, drive components, feedback, and controls.

These are not interchangeable deliverables.

An acceptance report should state the actual scope rather than relying on a broad product name.

Component Inspection Is Not Complete-System Verification

For a granite component, acceptance may cover dimensions, functional surface geometry, mounting interfaces, and surface finish.

For a mechanical assembly, additional checks may cover the relationships between installed components.

If a complete motion system is included, its acceptance requirements must be separately defined. A granite component report alone should not be presented as proof of the complete machine’s positioning or motion performance.

A useful scope statement might read:

This report covers the dimensional and geometric inspection of the granite guideway component in the specified support condition. It does not certify the performance of a complete motion system.

The wording should match the actual order.

2. Identify the Part and Drawing Revision

A report must be traceable to the component being delivered.

Include:

• Customer or project reference.
• Purchase order reference, where applicable.
• Part name and part number.
• Drawing number and revision.
• Serial number or another agreed identification.
• Inspection date.
• Report number and revision.

If the drawing changes during manufacture, confirm which revision applies to the final inspection.

Any approved deviation should be identified through the agreed documentation process rather than left as an unexplained difference between the drawing and the report.

ZHHIMG’s guideway inspection guidance specifically includes part identification and drawing revision among the required report details.

3. Link Each Result to an Agreed Requirement

A result is useful only when the reader can see what it was compared against.

The report should link each inspected feature to:

1. Its drawing or specification reference.
2. The characteristic being assessed.
3. The acceptance limit.
4. The measurement result.
5. The applicable acceptance decision.

Avoid a report that lists several numbers without showing which surfaces, lines, or interfaces they describe.

Use a Feature-Based Results Table

The following is a format example only. It does not specify ZHHIMG capability or universal acceptance limits.

Not every project requires every item. Inspection should follow the functional requirements of the component.

ZHHIMG’s published guidance identifies guide-surface geometry, surface finish, datum relationships, and interface positions as component-level acceptance topics.

4. Make the Datum System and Measurement Setup Clear

The report should explain how the component was supported and referenced during inspection.

At a minimum, agree which setup details must be recorded:

• Component orientation.
• Support locations.
• Support arrangement.
• Datum surfaces.
• Leveling or setup procedure, where relevant.
• Installed or removed accessories.
• Whether inspection occurs before or after assembly.

A labeled sketch or setup photograph can communicate these details more clearly than a short note.

ZHHIMG’s purchasing checklist calls for factory inspection on the designed support arrangement and for the measurement method and conditions to be reported.

Why the Setup Belongs in the Report

The purpose is reproducibility.

If the customer later checks the component using a different setup, the original report should contain enough information to identify that difference before drawing conclusions about the product.

For an agreed acceptance procedure, define the setup before manufacture—not after a disputed measurement.

5. Record Relevant Environmental Conditions

The report should identify the environmental conditions required by the inspection plan.

Depending on the project, this may include:

• Temperature during measurement.
• Agreed temperature range or stability criteria.
• Component stabilization requirements.
• Relevant environmental observations.
• Any other conditions required by the acceptance procedure.

Avoid unsupported statements such as “measured at constant temperature” without defining what that means for the project.

ZHHIMG’s published guideway guidance includes thermal conditions during operation and final inspection among the requirements to discuss before ordering.

If the application has demanding environmental requirements, the buyer and supplier should agree on how those conditions will be established, monitored, and documented.

6. Describe the Measurement Method and Coverage

“Measured with precision equipment” is not a complete explanation.

The report should identify the method used for each required characteristic and provide sufficient detail to understand the measurement coverage.

Depending on the inspection plan, include:

• Instrument type and identification.
• Measurement direction.
• Measurement locations.
• Sampling pattern or line layout.
• Inspected length or area.
• Relevant calculation or evaluation method.
• Any excluded areas or access limitations.

ZHHIMG’s guideway guidance explicitly calls for measurement locations or a layout, along with instrument identification and recorded results.

Show What Was Actually Measured

For a broad guide surface, a measurement layout may identify inspected lines or sampling locations.

For a beam, it may show the evaluated direction and functional length.

For several related faces, it may identify each face and the datum relationship used for evaluation.

The report should not imply broader coverage than the inspection actually provides.

7. Report Surface Geometry and Surface Finish Separately

Functional geometry and surface finish should appear as separate requirements when both are specified.

A guideway inspection plan may include:

• Flatness of a functional surface.
• Straightness along a defined direction.
• Parallelism between specified faces.
• Perpendicularity between reference surfaces.
• Surface roughness or another agreed surface-condition requirement.

ZHHIMG’s air-bearing guideway guidance identifies these as separate specification topics rather than a single generic “precision” requirement.

The drawing and report should therefore avoid treating one result as a substitute for another.

If a surface finish requirement applies only to certain areas, identify those areas clearly. Likewise, geometric acceptance should refer to the specified functional surface or evaluation length.

8. Include Calibration Traceability Without Overstating It

Instrument calibration information helps document the measurement process, but it should not replace the actual product results.

Agree on what the buyer needs, such as:

• Instrument identification.
• Relevant calibration certificate reference.
• Calibration status at the time of inspection.
• Access to supporting calibration documentation, where required.

Keep the purpose of each document clear:

ZHHIMG’s published quality-control documentation distinguishes product inspection reports from calibration reports for measuring devices.

A calibration certificate for an instrument should not be described as a calibration certificate for the complete machine.

9. Agree on Measurement Uncertainty and the Decision Rule Where Required

If the acceptance procedure requires measurement uncertainty, define how it will be reported.

Also agree on the decision rule: the procedure used to determine conformity from the measurement result, its uncertainty, and the specified limit.

This is particularly important when the buyer expects a formal conformity statement rather than a simple list of measured values.

ZHHIMG’s guideway inspection guidance includes measurement uncertainty and the conformity decision rule among the items to specify where required.

Do not leave this discussion until a result is close to an acceptance boundary. The buyer and supplier should understand the agreed approach before inspection begins.

10. Separate Pre-Assembly and Post-Assembly Checks

If the order includes additional hardware, the report should distinguish the condition in which each measurement was made.

For example:

If bearings, carriages, columns, or other components are included, identify whether their installation forms part of the supplier’s acceptance scope.

ZHHIMG’s published acceptance framework separates component geometry from mechanical assembly checks and complete-system verification.

The report should make the same distinction.

Example: A Practical Report Structure

The following outline can be used when discussing documentation with a supplier. It is a suggested structure, not an issued ZHHIMG inspection certificate.

Section A: Identification

• Customer and project.
• Part name and identification.
• Drawing number and revision.
• Inspection date and report number.

Section B: Inspection Basis

• Approved drawing.
• Referenced specifications.
• Agreed acceptance criteria.
• Approved deviations, if applicable.

Section C: Setup and Conditions

• Support arrangement.
• Component orientation.
• Datum references.
• Assembly condition.
• Relevant environmental conditions.

Section D: Measurement Methods

• Instruments and identification.
• Calibration references.
• Measurement layout.
• Evaluation methods.
• Stated limitations.

Section E: Results

• Feature-by-feature requirements.
• Recorded values and units.
• Supporting plots or measurement maps where agreed.
• Acceptance assessment.
• Uncertainty information where required.

Section F: Review and Release

• Inspector identification.
• Authorized review.
• Report revision.
• References to related delivery documents.

Questions to Ask Before Placing the Order

Before production starts, confirm the following with your supplier:

1. Does the quotation cover a granite component, an assembly, or a complete motion system?
2. Which surfaces and interfaces will be inspected?
3. Which drawing revision and acceptance limits apply?
4. What support arrangement will be used?
5. What environmental conditions will be documented?
6. How will the measurement locations be shown?
7. Which calibration information will accompany the report?
8. Is uncertainty reporting required?
9. What decision rule will be used where a conformity statement is required?
10. Which checks remain for the customer after delivery?

Resolving these questions early helps align the quotation, manufacturing plan, inspection report, and receiving process.

Frequently Asked Questions

Is a flatness result enough to accept a granite air-bearing guideway?

Only if that is the complete agreed requirement—which may not be the case. A project can also require straightness, relationships between faces, surface finish, mounting interfaces, and other checks. Define acceptance from the application and drawing rather than from one headline value.

Does a granite inspection report prove positioning accuracy?

No. A component inspection report should not be used to claim the performance of a complete motion system. Any system-level performance requirements must be separately defined and verified within the agreed supply scope.

Should the report show the measurement locations?

Yes, when needed to understand the coverage and evaluation. Agree whether the report will include a measurement layout, line identification, sampling locations, or another appropriate representation.

Should support conditions be recorded?

The relevant support arrangement should be defined and documented as part of the agreed inspection procedure. ZHHIMG’s purchasing guidance calls for inspection on the designed support arrangement.

Can the customer request a specific report format?

Include the required format with the RFQ so that the supplier can review its content before quotation and production. ZHHIMG’s published product guidance states that report format and acceptance criteria should be agreed before production.

Discuss Your Granite Guideway Inspection Requirements with ZHHIMG®

A useful acceptance report connects the drawing, measurement setup, inspection method, and recorded results. It also makes clear where component acceptance ends and assembly or system verification begins.

ZHHIMG® supplies custom granite guideways, bases, beams, and related structures to customer drawings, with inspection requirements defined around the agreed project scope.

When requesting a quotation, provide:

• Your drawing and current revision.
• Functional guide surfaces and datum references.
• Required geometric and surface specifications.
• Intended support and assembly conditions.
• Acceptance limits and reporting requirements.
• Any required report template.
• A clear description of the supply scope.

Submit your drawing and inspection requirements through the ZHHIMG website inquiry form.

Agree on the evidence of conformity before production begins—not only when the component is ready to ship.