Compact Roundness


Available on backorder


• Best-in-class rotational accuracy in compact type roundness
measuring instruments
• Fine adjustment on both X- and Z-axes
• Multiple analyses through simple operation
• D.A.T. function *except for centering/leveling device: Analog mic-head type
• Scaled Z-axis
• Continuous ID and OD measurement
• High-precision air bearing
• Wide-range detector
• Simple setup and display of results
• Built-in printer
• Supports 16 languages

Simple, interactive display screen

The large color LCD screen with backlight shows easy-to-understand measurement results and graphs. Forms can be checked and notch processing can be set while observing the displayed graphs.

Notch processing

Unwanted data, such as that produced by notches or scratches, can be excluded from the analysis if desired. Select between [Automatic setting] and [Arbitrary setting].


Model RA-120
Rotational accuracy:  (0.04+6H/10000)µmH: Probing height (mm)
Rotating speed:  6rpm
Table top diameter:  ø 1.96” (150mm)
Centering range :±.12” (3mm)
Leveling range:  ±1°
Maximum probing diameter:  ø 11” (280mm)
Maximum workpiece diameter:  ø 17.3” (440mm)
Maximum workpiece weight:  55 lbs (25kg)
Vertical column  (Z-axis)
Vertical travel:  11” (280mm)
Feeding: 1.18” (30mm)/rev. (coarse) 0.039” (1mm)/rev. (fine)
Maximum probing height:  11” (280mm) from the turntable top
Maximum probing depth:  3.94” (100mm) (min. ID: 1.18”(30mm)
Horizontal arm  (X-axis)
Horizontal travel:  65” (165mm) (Including a protrusion of 1” (25mm) the turntable rotation center)
Probe and stylus
Measuring range:  ±1000μm
Measuring force:  7 to 10mN
Standard stylus:  12AAL021, carbide ball, ø1.6mm
Measuring direction:  Two directional
Stylus angle adjustment:  ±45° (with graduations)
Data analysis unit:
Data sampling points:  3,600 points/rotation
Data analysis items: Roundness, Coaxiality, Concentricity, Flatness, Circular runout (radial), Circular runout (axial), Squareness (against axis), Squareness (against plane), Thickness deviation, Parallelism
Reference circles for roundness evaluation:  LSC, MZC, MIC, MCC Recording device:
Recording device: Built-in thermal line printer
Recording magnification:  X5 to X200,000, Auto
Roughness component reduction: Low pass filter, band pass filter
Filter type: 2CR-75%, 2CR-50%, 2CR-75% (phase corrected) 2CR-50% (phase corrected), Gaussian, filter OFF
Cutoff value: 15upr, 50upr, 150upr, 500upr, 15-150upr, 15-500upr