ALIGNMENT SERVICES, LLC

 

Serving Industry For 30+ Years

High Accuracy On-Site Measurement

Technology, Equipment, and Services for Precision Large Scale Dimensional Metrology

 

Increase Production, Improve Quality, Maximize Revenue

Contact ASC to Discuss Your Project

 

 

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Just The Facts:

·         Applications

·         Technology & Equipment

·         Software Download

·         Experience

·        Contact ASC

 

 

 

 

 

 

 

 

 

ASC's Precision Large Scale Dimensional Metrology service, training, & equipment is the result of extensive professional experience in the field, utilizing traditional and emerging measurement technology.
Engineering Degreed Measurement Specialists provide expertise for the array of technologies including Optical Tooling, Laser Instrumentation, Electronic Triangulation, and Photogrammetry Systems.
Our mission is to provide the highest accuracy, technically advanced, dimensional metrology available.

 

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Applications:

OPTICAL ALIGNMENT & PRECISION MEASUREMENT
PRECISION LARGE-SCALE DIMENSIONAL METROLOGY

Equipment and Techniques Providing State-Of-The-Science Accuracy.

_Rotating Shaft Alignment

.Straightness measurements

.Determination of hot running -vs- cold static alignment Hot-vs-Cold Shaft Alignment

.Line bore and bearing alignment

_Gear Trains

.Parallelism and perpendicularity

_Compressor Trains

.Setting level or to a predetermined reference

.Cross Head perpendicularity

.Cross Head -to- Cross Slide alignment

.Alignment checks for on-site machining

_Turbines

.Precision alignment to pumps, generators, and connecting shafts

_Jig & Fixture

.Accurate positioning

.Coordinate control of datums

.Controlled positioning of keys, pins

_Optical Alignment to Non-Gravity Reference

.Prop-shaft & engine alignment

_Monitoring of Mechanical Movements

.Dynamic process control & analysis

_Roll Alignment

.Synthetic film and paper mill roll alignments

_Extruder Alignment

_Machine Tool Analysis

_Feature Measurement

.x,y,z coordinate measurement of features

_Training & Consulting

.Design and analysis of equipment and techniques

.Custom Software design

Industry Application Areas (partial listing):

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A Comparison of the Technologies:

Laser Trackers / Scanners:

General Description, Tracker: Uses one angle+distance sensing instrument which automatically tracks a target. The Tracker instrument digitally transmits two angles (H&V) & a distance to driving computer software. Individual instrument calibration is checked using software combined with on-site target manipulations; Distance is measured via laser ADM/interferometry and its accuracy is often assumed. Software determines the x,y,z coordinate data, provides laser tracking feedback, and usually more.
Tracker Targeting: Contact. The target is a spherical mounted retro- reflector (SMR) {retro-reflector mounted in a spherical ~steel ball}. Contact targeting options are numerous and build on nesting fixtures which index with the SMR.
Tracker Accuracy @ 16 ft target (typ): +-.001 inch (3 axes polar tolerance). This based on: One inst, Accuracy Statement per below, Ideal environment.
Tracker Accuracy Statement: General stated accuracy is 1 part in 1 million (w/r target distance).
Comments: On-site instrument calibration check is generally available; Mounting of laser and overall component positioning may be critical; Instruments may be temperature sensitive and typically require warm-up; Heating systems within the instruments are common; An unavoidable lack of redundancy exists when using only one instrument; Engineered technique can produce high accuracies; When the laser beam LOS is broken during measurement the beam is typically `reset' via a `local' or `home' positioning or a EDM optimization (ADM); Considered one of the most accurate technologies; Once calibrated and running, a large number of data measurements may be quickly obtained;
Laser Scanners are also available for non-contact high density point requirements & reverse engineering; Accuracies vary.

Electronic Triangulation:

General Description: Uses two or more angle sensing instruments, typically theodolites. Each instrument digitally transmits two angles (H&V) to driving software on a portable computer. A known distance, usually a NIST traceable Invar calibration rod, is used to calibrate the system. Individual instrument calibration is usually assumed; Advanced systems allow for checking instruments and double-centering. Software determines the x,y,z coordinate data and usually more.
Targeting: Contact or Non-Contact. Laser dot projection may be used for Non-Contact targeting. Contact targeting options are numerous and utilize conventional OT systems.
Accuracy @ 16 ft target: +-.0017 inch (3 axes polar tolerance); less than +-.0015 inch (single axis). This based on: Two insts, Insts angle accuracy = +-.5 sec, Targeting accuracy = +-.001 inch, Cal dist= 144+-.0002 inch, Ideal strength-of-angle for insts and targets, 100% calibration, Ideal environment.
Accuracy Statement: A specific accuracy statement is complicated by many different variables including the relative instrument/target geometry. Generally, a target position can be determined to within about .002 inch within a 10x10x10 ft volume when using two fractional arc_sec insts.
Comments: On-Site instrument calibration is typically not available each time used, driving software should allow for instrument accuracy checks; Accuracy is dependent on geometrical arrangements of instruments and targets; Redundancy always exists thus allowing closure.

Electronic Trilateration:

General Description: Uses one or more angle+distance sensing instruments, typically total-station theodolites. Each instrument digitally transmits two angles (H&V) & a distance to driving software on a portable computer. Individual instrument calibration is usually assumed; System may allow for checking of instruments. Software determines the x,y,z coordinate data and usually more.
Targeting: Contact typical (refelctive targets); Non-contact also available.
Accuracy @ 16 ft target: ~+-.020 inch (3 axes polar tolerance), based on: One inst, Inst angle accuracy = +-.5 sec, EDM distance accuracy = +-.020 inch, 100% calibration, contact targeting, Ideal environment.
Accuracy Statement: "Angle reading accuracy of +-.5 sec (corresponds to a lateral deviation of +-.001 inch @ a distance of 34 ft); EDM distance typically has an absolute precision of +-.020 inch with a .004 inch resolution. Relative measurements over short distances and coordinates lateral to LOS may have accuracy better than +-.020 inch."
Comments: On-site instrument calibration is generally not available, driving software should allow for instrument accuracy checks; Accuracy may be improved via geometrical arrangements of instruments and targets; maximum target face angle is +-~45 arc_deg.

Digital-PhotoGrammetry/Video-PhotoGrammetry:

General Description: Uses one or more camera systems. Each camera digitally obtains an image of the measurement area. Two or more images are collected for triangulation.
Targeting: Typically Contact; Targets are usually of a self-adhesive plastic film type.
Accuracy @ 16 ft target: ~+-.003 inch (single axis), ~+-.006 (3 axes polar), ideal situation; Accuracies subject to change as photographic resolutions increase.
Accuracy Statement: "Close-range photogrammetry is capable of producing accuracies on the order of 1 part in 100,000 of the maximum diameter of the object photographed; Sometimes better."
Comments: Digital images are usually post analyzed; Stable platform for camera(s) normally not required; Dynamic objects may be measured; A large number of photograph images are often necessary to obtain highest accuracy; Electronic TriLateration/TriAngulation (ET or Trilogy) type systems are sometimes employed for additional control and accuracy; Camera_to_target geometry must be considered.

Conventional Optical Tooling:

General Description: Typically one or more Optical Tooling (OT) Transit Squares are calibrated on-site to produce parallel & orthogonal lines-of-sight (LOS) using the instruments optical and mechanical systems. Perpendicular distance is measured from LOS to subject target via refraction of LOS using optical micrometer; a single axis coordinate. Measurements are manually recorded.
Targeting: Generally a Contact system using fixed bi-filar targets and paired-line scales. Many designs and options exist and custom targeting is common.
Accuracy @ 16 ft target: +-.001 inch (single axis, ideal environment).
Accuracy Statement: The greater of +-.001 inch, +-1 arc- second. Targeting distances are generally made less than 50 ft.
Comments: Calibration is recommended each time used; The successful application of this technology generally requires technical expertise; On-site proof of accuracy is available.

ASC provides the above summary of the various technologies available in the large scale dimensional metrology field. Our goal is to recommend and use the best technology for the subject measurement.

Please contact ASC to discuss a specific project or obtain additional information.

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Alignment Services, LLC


USA
307-733-7245

E-Mail ASC@GoMeasure.com

 

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