for high-precision tube ID and OD metrology

TubeInspect is a modular, non-contact optical measurement system that provides micron-precision 3D measurements of tube or cylinder interiors and exteriors. Its small-diameter side-looking probe reaches inside tubes to acquire their complete inside geometry. The TubeInspect

  • Can measure every dimensional detail of tube ID and OD, including undercuts, chamfers, threads, rifling, o-ring grooves, splines, lands, edge breaks
  • Enables fully configurable automated digital inspection
  • Can detect micron-size dimensional or surface defects such as porosities, cracks, and scratches
  • Is able to measure surface roughness as well as thickness of semi-transparent coatings.

Novacam TubeInspect with a 4-axis inspection station

Novacam TubeInspect with a 4-axis inspection station



TubeInspect in action

In this video, the TubeInspect scans both the inside and the outside of a metal barrel that is fixed on a spinning chuck.

Note: If the tube/cylinder/bore you want to inspect needs to remain stationary (i.e., it cannot be spun as is done in this video), no problem – simply check out Novacam’s BoreInspect system that features our rotational scanner.



  • Optical, non-contact, non-destructive
  • 2D and 3D surface and subsurface characterization; diameter, circularity, cylindricity, runout, taper, distortion, straightness
  • High-aspect-ratio features: undercuts, threads, grooves, cross-holes
  • Sub-micron resolution and excellent sensitivity and measurement repeatability

Imaging options

  • Line profiles
  • 3D images of internal and external surfaces
  • Height and intensity images of “unfolded” surfaces
  • Cross-sections of semi-transparent materials
  • Deviation maps

Detail of the inner surface of a rifle barrel

3D image of tube inner surface


  • Easily integrated in lab, shop, or fully-automated inspection setups. 
  • Reduces inspection cycle time: up to 30,000 measurements per second are obtained, each representing a 3D topographic point
  • Flexible options for evaluating inspected parts: measured features can be compared to CAD drawings or to a user-defined set of locations, nominals, and tolerances
  • Simple scan definition and execution: The scanning sequence is defined once by teaching the system with a joystick. The scanning sequence can later be executed with the push of a button.
  • Time-saving automated reporting: Following a scan, go-no-go reports can be produced, and results logged in a manner compatible with industry-standard mechanisms
  • Easy part handling: The part fixture is selected to make handling easy and to ensure good repeatability
  • Adaptable to harsh environments
  • No consumables are needed: Optical probes do not come in contact with the measured samples, and therefore do not wear out like contact probes. Accidental damage is rare−probes are designed to be rugged.



3D metrology and imaging of tubes for industry and R&D

  • Quality control
  • Automated 3D production inspection, geometric dimensioning and tolerancing (GD&T)
  • Statistical process control (SPC)
  • Research and development (R&D) inspection
  • Reverse engineering and part-to-CAD
  • Maintenance, repair and operations (MRO)
  • Profilometry in hostile environments: radioactive, cryogenic, very hot

Typical measurements on tube ID/OD

  • Full geometry, diameter, circularity, cylindricity, taper, runout, etc.
  • Deviation from CAD model, GD&T
  • High-aspect-ratio features: undercuts, steps, O-ring grooves, threads, channels, sharp edges, steep slopes, and cross-holes
  • Volume loss: surface wear or other damage
  • Defects: corrosion, pitting, cracking, denting, scratching, porosity
  • Surface roughness: linear or area roughness
  • Thickness of semi-transparent coating: single-layer or multilayer films

Examples of tube inspection applications

Measurement, visualization, and inspection of ID and OD surfaces of:

  • Various tubes, cylinders, and shafts in the aerospace and automotive industries
  • Example from aerospace: jet engine shaft MRO (maintenance, repair and operations)
  • Examples from automotive: drive shafts, axles, threads, splines, gears, drive teeth
  • Vials, cylindrical containers in the biomedical and chemical sectors
  • Cylindrical devices in the medical sector
  • Rifle bores and rifle chambers
  • Tubular parts in high-precision machining, drilling, injection molding, 3D printing, additive manufacturing, casting, extrusion dies
  • Composite tubes and rods


Gallery (click images for close-up)

Long cylinder bore (barrel) measurement

Metal tube (rifle barrel) being installed in a chuck. The TubeInspect small-diameter probe is visible next to the operator's shoulder.

Metal tube (rifle barrel) being installed in a chuck. In this setup, the non-contact optical probe (visible next to the operator’s shoulder), moves vertically along the z-axis.

Descending probe acquiring the ID of the spinning tube (rifle barrel)

Descending probe acquiring the ID of the spinning tube

Descending probe acquiring the OD of the spinning tube (rifle barrel)

Descending probe acquiring the OD of the spinning tube

Detail on the inside surface of a rifle barrel and chamber

Detail view of the inside surface of a rifle barrel and chamber

Tube inspection - porosities on the inside of a rifle barrel

The user can zoom in to inspect porosities on the inside surface

The data acquired by TubeInspect can be viewed and analyzed using any GD&T software (like PolyWorks) or any integrated 3rd party CAD software package.

The measurement data acquired can be viewed and analyzed using any GD&T software (like PolyWorks) or any integrated 3rd party CAD software package.

Analysis results: the user defines the measurement data to be collected – roughness, groove depth/width, pitch, straightness, thread characteristics, etc.

Three-dimensional surface analysis can include 3D deviation maps

Three-dimensional surface analysis can include 3D deviation maps

A 3D deviation map showing rifling inside a rifle barrel

A 3D deviation map showing the rifling inside a rifle barrel

Diameter deviation map for a rifle barrel (5.8-mm-diameter)

Diameter deviation map for a rifle barrel (5.8-mm-diameter)

The TubeInspect can also capture the "unfolded" tube ID surface as a height image (top) and/or an intensity image (bottom). For this 5.8-mm-diameter 148-cm-long tube, the proportions of the inner surface were adjusted for easier viewing.

The TubeInspect can also capture the “unfolded” tube ID surface as a height image (top) and/or an intensity image (bottom). For this 5.8-mm-diameter 148-cm-long tube, the proportions of the inner surface were adjusted for easier viewing.


Fuel injector nozzle & nozzle needle measurement

Inside diameter (ID) surface of a fuel injector nozzle (click for close-up)

Outside diameter (OD) of the matching fuel injector nozzle needle


Metrology Software

Data acquisition

The TubeInspect system comes with Novacam high-performance data acquisition software, which is

  • PC, Windows®-based
  • User-friendly for scan programming and visualization

An application programming interface (API) is available for system integrators and OEMs. With the API, a wide variety of online and offline applications can be accommodated.

Novacam data acquisition software


Data analysis and 3D imaging

The following options are available for data analysis and 3D imaging:

  • Data output options: 3D point cloud, height image, intensity image, roughness, diameter, STL file format
  • Integrated turnkey solution with PolyWorks InspectorTM
  • Output is exportable to turnkey integrated 3rd party CAD packages selected by the client:
    • CAD/CAM software: PolyWorks, Geomagic, SolidWorks, Creo Elements/Pro (Pro/ENGINEER), etc.
    • Imaging, visualization and numerical analysis software: ImageJ, Octave, MatLab, Mathematica, IDL, IGOR Pro
    • Surface and roughness analysis software
  • Exported data can be integrated with data loggers and SPC software

Deviation map of the inside surface of a rifle barrel acquired with TubeInspect

Deviation map of the inside surface of a tube

Option: Novacam volume loss application

Novacam Volume Loss application processes the acquired surface dimensional data to determine volume loss from abrasion and wear:

  • with micron precision
  • on samples and components of various shapes and sizes, including inner and outer surfaces of tubes

Novacam Volume Loss Calculation Application

Novacam Volume Loss Application – click for closeup

Novacam Volume Loss Application: scan control user interface

Novacam Volume Loss Application – click for closeup

System components

System components

The TubeInspect is a modular system comprised of 1) an optical probe, 2) Microcam interferometer, 3) an inspection station, 4) a PC, and, optionally, 5) multiplexing hardware (not shown in diagram).

The inspection capabilities of the TubeInspect are determined jointly by its components:

1) Optical probe

Novacam non-contact optical probes come in several standard sizes and lengths and can be custom built as well.

Tube parameters

Standard probe characteristics*


Tube inner diameter range
Probe diameter
Spot size
Probe length
2 - 6113 - 2250 - 200**
4 - 103.05
4 - 203.05 (extended range)
6 - 144.6
6 - 254.6 (extended range)
20 - 5012.7
50 - 25018

*Only standard probe characteristics are listed in this table. Non-standard diameters and lengths are custom-built upon request.
**Maximum probe length may be limited by mechanical constraints. Probes as long as 2 m have been built.

2) Microcam interferometer

Microcam-3D profilometer (low-coherence interferometer) The Microcam interferometer provides the light source to the rotational scanner and processes the optical signal received from the scanner.
Technologylow-coherence interferometry
Light wavelength1310 nm, infrared
Non-contact measurements
Depth of fielddepends on selected probe parameters,
see table Standard probe characteristics above
Scanning depth range options*3.5 mm7 mm5 mm
Acquisition (A-scan) rate2.10 kHz1.05 kHz30 kHz
Axial (Z-axis) resolution< 0.5 µm
Light spot size (Lateral [XY-axis] resolution)4.1 - 146 µm, depends on selected probe parameters,
see table Standard probe characteristics above
Standoff distance1 - 100 mm for standard probes
up to 1 m for non-standard probes
Repeatability< 1 µm
Thickness measurements
Thickness measurement range (in Air, IR = 1.0)10 µm - 3.5 mm 10 µm - 7 mm 20 µm - 5 mm
Typical materials for thickness measurementsglass, polymers, multi-layer films, coatings, plastics, silicone, liquids, specular or non-specular
Sample reflectivity0.1 - 100%

*To further increase maximum scanning depth, a mechanical displacement axis is available.

3) Inspection station

Inspection station configurations are application-dependent and can be supplied by Novacam. Fixturing for the part is not included.
Lab and shop floor inspectionThese inspection stations typically include probe displacement in 2, 3 or 4 axes, and a motorized spinning fixture for the inspected tube. Motion controllers are included.

Granite tables are optionally available and recommended for some applications.
Automation and inline industrial inspectionThe TubeInspect optical probes may be integrated with third-party CMMs (coordinate-measuring machines), CNC (computer numerical control) machines, or any robots (as a robot end-effector) to support high-volume continuous flow manufacturing.

Two examples of inspection station configurations

A) TubeInspect integrated with a 4-axis inspection station
Here, for both the ID and OD inspection, the probe is displaced vertically while the inspected probe is spun on a rotational stage.

Benefits of this configuration: With just one automated scanning sequence, the tube can be measured and characterized both on the inside and outside.

Inspecting the tube ID

Inspecting the tube ID

Inspecting the tube OD

Inspecting the tube OD


B) TubeInspect in a bottom-probe configuration
Here, the probe displacement stages and the probe are enclosed below the inspection table, while the rotational stage with the tube fixture are on top. The probe enters the spinning tube from below.

Benefits of this configuration: Unintended operator contact with the probe is prevented in a shop environment.

TubeInspect in a bottom-probe configuration

TubeInspect in a bottom probe configuration

Probe entering a tube from below the inspection table

Probe entering a tube from below the inspection table

4) PC, monitor and joystick

The TubeInspect system comes with a PC (with Novacam acquisition software), a monitor, mouse, and joystick.
Polyworks InspectorTM metrology software for full GD&T inspection of the parts can be purchased with the system. Custom data processing, reporting and defect detection programs can also be written based on client requirements.See “software” tab for more detail.

5) Hardware for multiplexing support (optional)

Optical switches are available for multiplexing up to 8 probes to a single Microcam interferometer.

Additional Info

Standard system configuration

A standard configuration of the TubeInspect includes:

  • Microcam-3D interferometer
  • 1 standard 4.6 mm-diameter side-looking probe (for inspection of bores up to 660 mm (26″) deep)
  • 3-axis inspection station and 3-axis motion controller
  • 1 chuck with motor and motion controller for rotating the inspected tube
  • PC with Novacam acquisition software
  • 1 year warranty

Instrument safety

  • Microcam systems feature an in-probe red laser pointer (650 nm wavelength) for alignment purposes.
  • Microcam systems are Class 1M Laser products, with < 20 mW of infrared and < 5 mW of in-probe laser pointer.
MicroCam non-contact profilometers are Class 1M laser products


How long does it take to scan a tube with TubeInspect?

  • Scan time depends on the tube size, tube length, what aspects of the tube you need to measure, and the rotational speed of the stage (chuck) holding the tube. The TubeInspect (with Microcam-4D) acquires up to 30,000 measurements per second, which represents roughly 1 million 3D topography points in 33 seconds. Standard speed of part rotation is 2 rotations per second. The speed can be higher depending on the application (e.g., depending on tube size, weight, and related safety factors). The user selects the rotation speed, the probe acquisition speed, and the pitch of the spiral, which together determine the number of points that will be acquired and the time the scan will take. In general, dimensional measurements (for GD&T) require the least amount of points and can be achieved the fastest. Roughness callouts may take 3 to 4 seconds each. Defect detection requires the most amount of points, of course depending on the size of defect you are looking for. For help with estimating the time required to scan your tubes or cylinders, please contact us.

Can TubeInspect measure internal dimensions of cavities that are not tubular in shape?

  • Yes, depending on the geometry of the cavity. Note that if the workpiece containing the cavity cannot be rotated (i.e., it needs to remain stationary), you may want to consider using the BoreInspect system, which comes with a rotational scanner.

Is the system easy to use?

  • Yes.  The scanning sequence (recipe) can be programmed with a joystick and can be recalled at later times with the push of a button.

Is the system able to work right on production floor?

  • Yes. The system is ideally suited to both lab and shop floor inspection. Inline and robot setups are an option. The non-contact probes can even be configured to work in hostile environments such as extremely hot, cryogenic, or radioactive.

Can TubeInspect give us automated measurements and reports?

  • Yes.

I noticed the tube spins around the probe.  Can any runout of the chuck affect the scan data?

  • No, runout is not an issue with TubeInspect. Gauge rings are used to calibrate the system and validate the results. The system provides micron-level diameter measurement repeatability.

Does the TubeInspect probe have to be on the centerline of the tube when measuring the tube ID?

  • In most cases, the probe is not positioned at the centerline of the rotated tube.  The probe simply needs to be lowered into the tube at a constant distance from the tube’s ID surface.

  • For any questions or for assistance with configuring your optimal TubeInspect system, please Contact us.