SPC (Statistical Process Control) measurement

It is a testing measurement to check e.g. measurement system capability. Usually a special SPC part with known values is used. Comparing the actual measurement values with the known features, it can be checked, if a measurement system has a proper operational system mode or if it has to be re-calibrated.

The known SPC part features are typically stored in the SPC measurement template.

InnoMeas RMS Systems

InnoMeas RMS systems are designed as standalone comprehensive inspection systems. All processes like feeding the devices under investigation, coarse pre-inspection, inspection of particular details etc. are controlled internally by the InnoMeas RMS station itself. Part loading can be achieved by robots or manually. However, InnoMeas RMS systems can be embedded in an automated production line.


1: Measuring chamber
2: Feeding station
3: Device under test (DUT): 
 i.e. car alloy wheel
4: Monitor for DUT 
 position & centering
5: Safety light curtain
6: Operator‘s push button assembly
7: Handheld scanner 
 for DUT identification
8: Monitor for displaying results

Measurement Chamber

When the device under investigation has been moved into the measurement chamber it is set to fixed position, e.g. on a rotary stage for widely rotationally symmetric parts.
A dedicated measurement procedure is launched. Usually this procedure consists of a sequence of application related measurement steps, e.g. a coarse overall pre-inspection followed by a precise measurement of particular features of the device under test. Intermediate results are displayed and compared with related reference values.
Final results can displayed and stored as local values (e.g. in polar, cylindrical or Cartesian coordinates) or as averaged over height and/or circumference with a survey of local deviations. Restrictive or warning limits can be preset. Related alerts are displayed on the screen.
Example for a setup of a measurement chamber

Coarse inspection system:
1: Illumination assembly
2: Imaging camera
Precise measurement system:
3: Telecentric illumination
4: Telecentric imaging
Positioning system:
5: Rotary stage
6: Traverse assembly 
 for height adjustment

Feeding station

Especially, when the parts under investigation are manually loaded a precise positioning is required. In the measuring chamber a reasonable space for illumination and vision angles is required. Additionally geometrical suppression of stray light and ambient light must be achieved and needs space as well. Contamination by e.g. dust particles must be drawn to a minimum at that.
Therefore centering and positioning devices are placed outside the measuring chamber. Moreover, it allows convenient and safe handling of even heavy samples. The samples only need to be placed on the loading desk. Positioning and subsequent feeding to the measuring chamber will follow under computer control.
Potential layout of a feeding station

1: Loading desk
2: Sample holder for centering &
 feeding to the measuring chamber
 (in downward position)
3: Pushing actuator for placing the 
 sample onto the sample holder
4: Observation screen
5: Door to measurement chamber 
 (in upward position)
6: Operator‘s push button assembly
7: Light curtain for worker‘s safety
8: Handheld scanner (sample identification)

Leave a Reply