Probing and Metrology Systems

InsituTec offers gauging products and solutions which provide unique capabilities for quality inspection on both the macroscale and microscale. Our premier products, the AccuSurf gauge accompanied by the MicroTouch Sensor extends the functionality of a CMM to enable microscale form measurements, nanoscale surface metrology, and roundness measurements.
Performance specifications such as throughput, part integrity, clearance issues, and data collection rates are defined by the gauging or probing technology, the scan speed, scan force, probe aspect ratio, and the dynamic response of the probing system. InSituTec has unique probing technologies to enhance CMM capabilities Click on the category of choice to learn more.
AccuSurf 3DUltra precision multi-axis gauge head with rotary axis and up to 3 axis active force control for 3D scanning.
AccuSurf 3D
The AccuSurf Gauging System incorporates a state-of-the-art nanometer repeatable rotary axis with a multi-axis active scanning head. This advanced gauging system provides the ability to measure complex 3D surface profiles with < 20 nm repeatability, is capable of high scanning speeds with 1000’s of data points collected per second, has scanning forces less than 100 nN.
The AccuSurf gauge when accompanied with the MicroTouch Sensor System will extend, the functionality of a CMM to enable microscale form measurements, nanoscale surface metrology, and roundness, tasks that would otherwise require 3 different machines. This provides ability to measure shapes and parts that were otherwise difficult to measure such as freeform optics, inside channels and cavities of MEMS and soft exotic materials such as aerogels and roots of miniature threads.
Some Applications Using the AccuSurf 3D and MicroTouch
- Implantable microscale medical devices: hearing aid, pace maker, endoscope
- Telecommunications: optical camera cell phone lenses
- Spinal and Biologics: orthopedic bearing surfaces
- Automotive: rocker arms, diesel injectors, cams
- Soft materials: plastics and peek
Specifications
The AccuSurf is designed to rotate and scan a force probe with at least one axis of sensitivity or more. As a result, the rotary axis and radial scanner specifications are listed below showing the gauge heads' motion control capability.
| Spindle Information | Typical Specifications | Units |
| Synchronous error | Up to ± 1 | micrometers |
| Asynchronous error | < 10 | nanometers |
| Rotational Resolution/Control | 0.08 | Arc-seconds |
| Maximum speed | 10 | RPM |
| Radial Scanner Information | ||
| Displacement noise | < 0.5 | nanometers |
| Repeatability | 10 | nanometers |
| Accuracy | 25 | nanometers |
| Range | 100 | micrometers |
| Mechanical Bandwidth | 300 | Hertz |
| General Information | ||
| Gauge head weight | 3.3 | kilograms |
PreCess 2DThe PreCess gauging technology enables affordable high speed inspection of dimensional parts in precision manufacturing with accuracies better than 50 nanometers.
PreCess 2D
The PreCess 2D is a precision in-process gauge head that features
- 2 axis measurement with less than 50 nm accuracy
- high speed scanning up to 600 mm/s
- scanning or touch triggering modes
- crash and overtravel protection
- accept probe arms with very high lengths up to 200 mm
- thermally insensitive to temperature swings
- easily read gauge signals
- easily integrate to your machine
- compeititvely priced
The PreCess differentiates among competing technologies in “Dynamic Precision” or the inherent ability to reproduce highly accurate measurements at rapid speeds. This is important when considering high quality control measurements and high throughput demands on the manufacturing floor. Using highly precise movers or measuring machines with the gauge, the probe’s fast and precise scanning response is unparalleled in the metrology industry. Mounting the gauge head with a highly precise mover or measuring machine is of course critically important. However, many vendors provide precision movers but few provide precision gauging products with less than 50 nm accuracies while maintaining fast scanning speeds.
Specifications
General specifications are provided below for the gauge head and accompanying probe arms. Typical values such as travel, sensor noise, contact repeatability and accuracy are provided. The gauge heads are integrated into the customer’s process line for quality control. As a result, the wiring and integration issues will sometimes vary for each customer. We recommend contacting us to learn more about this product such as system integration, wiring, electrical outputs.
Table 1: Gauge Head General Specifications
| Typical Specifications | Units | Notes | ||
| Parameters | R-axis | Z-axis | ||
| Max Travel | ± 0.30 | ± 0.30 | mm | |
| Sensing Range | ± 0.30 | ± 0.30 | mm | A |
| Stiffness | 14,100 | 13,800 | N m-1 | |
| Inertial Mass | ~48 | ~73 | grams | |
| Noise Level | 34 | 35 | nm | C |
| Offset Drift | 0.04 | 0.13 | μm/°C | D |
- This range depends upon voltage gain setting.
- The InsituTec gauge head signals are calculated by employing a 1 kHz cut off filter for both R-axis and Z-axis. This value is based upon measuring 4 sigma over 5 seconds and voltage signals are calibrated using the smallest probe arm length (IT-PA-79).
- This parameter is the measured offset drift located at the center of the kinematic mount.
Table 2: Probing Typical Specifications
| Typical Specifications | Units | Notes | ||
| Parameters | R-axis | Z-axis | ||
| Frequency Response | 170 (125) | 102 (108) | Hz | A, B |
| Kinematic mount breakaway force | 720 (380) | > 2,200 | grams | A, C |
| Offset Drift | N/A | 0.84 | μm/°C | D, E |
| Linearity (over ± 0.05 mm) | < 50 | < 100 | nm | F |
| Max Hysteresis | < 10 | < 10 | nm | G |
| Lateral Compliance (normal to R-Z plane) | 5000 (1985) | 5000 (1985) | N m-1 | A |
| Rotational Error about Y-axis | 0.40 (0.95) | 0.40 (0.95) | ArcSec / μm | J |
- The values not in parenthesis are measured using probe arm IT-PA-79 (79 mm free length) and values in parenthesis are with IT-PA-171 (171 mm free length).
- The Z-axis is observed to have a lower natural frequency. In general, the stiffness of the stylus on end of the probe contributes to lower natural frequency. In practice, the normal force generated from the surface will, in most conditions, be acting along the longitudinal direction of the stylus. However in our test conditions the force was acting in the Z direction, not along the axis of the probe stylus. As a result, the Z-axis sensors will most likely have a natural frequency occurring closer to 125 Hz under the actual loading conditions that will be experienced during measurements.
- Both probe arms will breakaway for the same amount of displacement at the probe tip. This is because the effective stiffness of the intermediate probe arm is half of the stiffness compared with the short probe arm. As a result the breakaway of the probe arm from the kinematic mount will occur at approximately the same amount of displacement at the probe tip regardless of which probe length is used.
- The reported value is for the intermediate probe length. It is assumed the gauge head is mounted from the top. The total length of the gauge head is 70 mm and using the material’s CTE (coefficient of thermal expansion), this provides a total drift of 1.65 μm/°C for the gauge head. Secondly, the intermediate probe arm is measured to have a negative thermal growth of -0.81 μm/°C. Thus, the net result is 0.84 μm/°C total growth along the Z-axis direction.
- The R-axis direction is not experimentally reported because the gauge head was mounted to an aluminum plate. As a result, it is difficult to decouple the CTE of the mounting from the CTE of the gauge head when evaluating the experimental thermal tests. Nonetheless, we anticipate the R-axis thermal growth to be minimized because the probe arm is symmetrically designed in the gauge head.
- The linearity is dependent upon what type of trendline is used for the calibration curve fit. The data given in this report was fit with second order equations and the linearity is reported as the range of the residual error from this curve fit. The linearity may be improved by using a higher order curve fit. It is important to note for these experiments, we could not report linearity over ± 50 μm because the test apparatus (i.e. the nanopositioner) is limited to ±7.5 μm. Nonetheless, we clearly show the linearity for the R-axis direction is less than 10 nm excluding noise contribution from the inner probe tip dragging on the nanopositioner.
- Minimal hysteresis was observed in the R-axis direction. In most conditions for the Z-axis, minimal hysteresis was observed. However in a few conditions 20-30 nm of hysteresis was observed. We believe most of this was due to inadequate mounting of the nanopositioner.
MicroTouchA novel microscale force sensor capble of extracting surface finish and form in the same data set.
MicroTouch
InsituTec’s MicroTouch sensor is a metrology sensor with the capability of providing cost effective measurement of microscale parts and features that currently cannot be measured. This technology overcomes the shortcoming of existing techniques because it can measure high aspect ratio features, is highly repeatable because it does not stick to the surface, and provides high data rate scanning capability. In addition it provides the ability to combine three traditionally separate measurement capabilities, surface finish, form, and roundness into one instrument.
The MicroTouch sensor is a revolutionary new tactile probe designed for quality control of microscale manufacturing. The probes are typically 7 μm in diameter, 3.5 mm in length, and contact parts with < 100 nN forces. The probes are capable of measuring with 10 nm repeatability in contact and out-of-contact scanning modes. As a result, the MicroTouch sensors are applicable to wide range of parts from silicon MEMS structures to exotic materials such as aerogel foams to more traditional materials such as steels for medical implant parts. Optical components with free form shapes will also benefit from this quality control device. We have provided a few specifications below related to the probes size and scanning ability. Contact us to discuss in more detail our capabilities and how they can meet your requirements and learn how the MicroTouch will add significant value to your micromanufacturing processes.
Measurement Applications:
- Measure high aspect ratio microstructures
- Inspect Surface Wear on Thread Gauges
- Measure Very Delicate Surfaces
- Scan microscale optics
- Inspect microscale holes
Specifications
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Mechanical Parameters
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Specifications
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Tip Diameter
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7 micrometers
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Fiber Length
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~3.5 mm
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Contact Forces
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< 50 nano-Newtons
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Cartridge Casing
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Custom Sizing Available
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| Tip Velocity with wave on | ~ 1 m/s |
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Electrical Parameters
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Specifications
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Units
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Output Signal
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-10 to + 10
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Volts
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Repeatability a
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< 10
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nm
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Data Collection Bandwidth
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100
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Hz
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Signal Sensitivity (Typ)
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1
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V/um
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Scanning Capability
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Contact and Near Field
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Tip Overtravel Capability
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~ 1
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mm
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