ROMER Absolute Arm with Integrated Scanner - 7 Axis SI

Type: Inspection and Measurement

The universal scanning solution for all types of parts and applications.

The newly redesigned Romer Absolute Arm 7-Axis “SI” series with integrated laser scanner delivers the convenience of a fully integrated 3D scanning solution for a variety of applications. Use it for feature inspection to CAD, free-form surface inspection to CAD and reverse engineering. The scanner is incorporated into the seventh axis and rotates around the probe for a more natural feel. The SI version of the Absolute Arm is easily converted to an SE version to accept an externally mounted laser scanner.

Since its weight is balanced with ROMER’s Zero-G counterbalance, the arm is the easiest and most ergonomic in the industry. The feature pack contains the scanner interface, so no external controller box is required. Single button automatic laser power control allows scanning of different surface types. No warm up time coupled with no homing procedures means an operator can be up and scanning in just minutes.

ROMER Absolute Arm with integrated scanner is the first portable arm system in the market that is factory calibrated and certified to B89 specifications.


  • Patented Infinite Rotation in the principle axes allows access to difficult to reach areas, while avoiding damaging the arm against rotational hard stops.
  • Kinematic Probe Joint, the same type used in Hexagon Manufacturing Intelligence bridge CMMs, provides repeatable connection of probes, with no need for recallibration. Automatic and repeatable probe recognition allows you to store hundreds of calibrated probe profiles for instant recall.
  • Redesigned, ergonomic Pistol Grip handle increases operator comfort and productivity.  It is easy to hold, and is used to inspect parts or to interact with the software when in “mouse mode.” Haptic feedback vibrates the wrist to alert the operator in noisy shop floor environments.
  • Patented SpinGrips are infinitely rotating, low-friction “approved” hand hold positions for better user ergonomics. SpinGrips allow the arm to “float” in the operator’s hands, reducing stress on the arm thus maximizing accuracy and repeatability while minimizing user fatigue.
  • Absolute Encoders, super high-accuracy rotary encoders, designed specifically for Romer Absolute Arms, improve overall system accuracy while eliminating all complicated “homing” procedures.
  • Aerospace grade Carbon Fiber Tubes provide a lightweight, stiff structure that is thermally stable. Under normal usage the carbon fiber tubes have a lifetime warranty.
  • Low Profile Zero-G Counterbalance balances the arm’s weight for easy, operation with effortless control, even above and below the arm’s centerline. Better ergonomics means lower operator fatigue and better measuring results.
  • Integrated handle and lifting point under counterbalance allow for easy carrying.
  • Feature Packs plug into the base and provide interchangeable and upgradeable add-on capabilities such as WiFi connection, battery power, interface for laser scanners and more.
  • Universal quick mounting base attaches to a variety of available base and stand options including magnetic bases.
  • Fully integrated scanning solution – no additional cables or controller box
    • One button automatic laser power control – allows to scan on different surface types with minimal operator interaction
    • No warm-up time
    • Factory calibrated and certified scanning systems according to B89.4.22 (for Hexagon scanners only)
    • No coating or surface preparation necessary
    • Scanning and probing interchangeable, automated probe recognition
  • Calibrated Length Standard – ROMER provides a NIST traceable calibrated length standard with each arm to allow the operator to easily verify and document system performance for ISO or vendor requirements.

Featured Specifications

7-Axis ROMER Absolute Arm with Integrated Scanner Probing and Scanning Specifications – 73 series

Model3 Measuring Range Probing Point Repeatability1 Probing Volumetric Accuracy2 Scanning System Accuracy4 (with RS2) Arm Weights
7320SI 2.0 m / 6.6 ft. ± 0.044 mm / 0.0017 in. ± 0.061 mm / 0.0024 in. ±0.040 mm / 0.0016 in 8.3 kg / 18.3 lbs.
7325SI 2.5 m / 8.2 ft. ± 0.049 mm / 0.0019 in. ± 0.069 mm / 0.0027 in. ±0.042 mm / 0.0017 in. 8.6 kg / 19.0 lbs.
7330SI 3.0 m / 9.8 ft. ± 0.079 mm / 0.0031 in. ± 0.100 mm / 0.0039 in. ±0.060 mm / 0.0024 in. 8.9 kg / 19.6 lbs.
7335SI 3.5 m / 11.5 ft. ± 0.099 mm / 0.0039 in. ± 0.125 mm / 0.0049 in. ±0.074 mm / 0.0029 in. 9.2 kg / 20.3 lbs.
7340SI 4.0 m / 13.1 ft. ± 0.115 mm / 0.0045 in. ± 0.151 mm / 0.0059 in. ±0.091 mm / 0.0036 in. 9.5 kg / 20.9 lbs.
7345SI 4.5 m / 14.8 ft. ± 0.141 mm / 0.0056 in. ± 0.179 mm / 0.0070 in. ±0.107 mm / 0.0042 in. 9.8 kg / 21.6 lbs.


7-Axis Romer Absolute Arm with Integrated Scanner Probing and Scanning Specifications – 75 series

Model3 Measuring Range Probing Point Repeatability1 Probing Volumetric Accuracy2 Scanning System Accuracy4 (with RS2) Arm Weights
7520SI 2.0 m / 6.6 ft. ± 0.023 mm / 0.0009 in. ± 0.033 mm / 0.0013 in. ±0.029 mm / 0.0012 in. 8.6 kg / 19.0 lbs.
7525SI 2.5 m / 8.2 ft. ± 0.027 mm / 0.0011 in. ± 0.038 mm / 0.0015 in. ±0.032 mm / 0.0013 in. 8.9 kg / 19.6 lbs.
7530SI 3.0 m / 9.8 ft. ± 0.042 mm / 0.0017 in. ± 0.058 mm / 0.0023 in. ±0.042 mm / 0.0017 in. 9.2 kg / 20.3 lbs.
7535SI 3.5 m / 11.5 ft. ± 0.055 mm / 0.0022 in. ± 0.081 mm / 0.0032 in. ±0.051 mm / 0.0020 in. 9.5 kg / 20.9 lbs.
7540SI 4.0 m / 13.1 ft. ± 0.067 mm / 0.0026 in. ± 0.098 mm / 0.0039 in. ±0.060 mm / 0.0024 in. 9.8 kg / 21.6 lbs.
7545SI 4.5 m / 14.8 ft. ± 0.084 mm / 0.0033 in. ± 0.119 mm / 0.0047 in. ±0.070 mm / 0.0027 in. 10.1 kg / 22.3 lbs.

1 The Point Repeatability Test is the reference test to determine measurement arm repeatability with ball probe. The cone is in front of the machine. Points are measured from multiple approach directions. The average point and the deviation of each point to the average center are calculated. The result is the maximum range divided by two. 

2 The Volumetric Accuracy Test is the most representative test for volume measurement accuracy. A gage block with a known and certified length is measured several times throughout the working volume. This gage block is installed in different positions and measured depending on multiple approach directions. The result is the maximum deviation of the measuring distance less the theoretical length.

3 SI designates the ROMER Absolute Arm with integrated scanner.

4 The Scanning System Accuracy Test most accurately represents the reasonable expectations for machine performance in practical measuring applications while using the laser scanning method. The test consists of measuring a matte grey sphere with 5 different arm articulations. In each articulation of the arm the sphere is scanned from five different directions such that the majority of the sphere is scanned. The result is the maximum 3D center to center distance of the five spheres.