Sam`s Copy of Agilent 10774A Short Range Straightness Optics and
Contents
1. Gunsight or Autoreflection alignment method ONE LINEAR and ONE STRAIGHTNESS AXIS ea aes Straightness Interferometer Position A N Straightness i U Beam Interferometer Splitter Position B P B R ver ecei ra I lt e ai i 1 ffi i A Linear bade a l gt Beam oe spare Receiver Retroreflector Beam Beam Straightness Straightness Splitter A Splitter B Position A Position B OK OK Figure 7Y 6 One linear and one straightness axis User s Manual 7Y 9 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment Align the Straightness Reflector so that its mirror axis see Figure 7Y 2 is parallel to the laser beam and axis of travel This mirror axis forms the optical straight edge analogous to traditional straight edge Adjust the interferometer to align its optic to the reflector to obtain a measurement signal at the receiver green LED is on Fine adjust the interferometer bezel and reflector to obtain maximum measurement signal at the receiver monitor the voltage at the receiver test point Remove measurement slope This slope refers to the angle inscribed by the mirror axis and the axis of travel see Figure 7Y 10 Alignment procedures The following procedure describes the step by step alignment of an axis of straightness optics Figure 7Y 4 shows the measurement setup with2. interferometer angles can vary due to manufacturing tolerances Therefore the result must be multiplied by the calibration factor K which is stamped on each interferometer The final result is D 36KX for short range optics and D 360K X for long range optics Small pitch yaw or roll motions of the interferometer do not create a path difference and therefore do not affect the measurement accuracy This is an advantage of using the interferometer as the moving optic The two return beams from the Straightness Reflector combine in the prism at the same point where the beam from the laser head was split The combined beam is returned along the same path as the laser head s exit beam User s Manual 7Y 5 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment Installation and Alignment Pre installation checklist In addition to reading chapters 2 through 4 and Chapter 15 Accuracy and Repeatability complete the following items before installing a laser positioning system into any application g Complete Beam Path Loss Calculation see Calculation of signal loss in Chapter 3 System Design Considerations of this manual g Determine the direction sense for each axis based on the orientation of the laser head beam directing optic and interferometer Enter the direction sense for each axis into the measurement system electronics S
3. laser beam is centered over the intended measurement axis Lock down the laser head and beam splitter securely Make sure not to disturb the alignment Remove the referenced mirror Orient the Straightness Reflector horizontally or vertically to match the type of measurement to be made horizontal or vertical straightness Center the reflector about the laser beam The laser beam should strike centered between the two mirrors in the reflector The laser beams should now be aligned parallel to the axis of travel This ends the Autoreflection alignment method 7Y 12 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment Gunsight method 1 Position the optics for their near end of travel that is when the interferometer and reflector are nearest each other For short range measurements this should be about 100 mm 4 inches For long range measurements this should be about 1 meter 3 feet 2 Orient the Straightness Reflector horizontally or vertically to match the type of measurement to be made horizontal or vertical straightness 3 Select thesmall aperture on the laser head by rotating the front turret 4 Attach the round target supplied with the straightness optics to the entrance face of the interferometer Make sure that the target is centered over the interferometer bezel 5 Adjust the interferometer or laser beam so t
4. only the straightness axis shown With all optical components in place visually align the laser beam parallel to the axis of travel This may be done by blocking the laser beam with a piece of paper and moving this paper along the axis of travel while watching the beam creative to the axis Align the laser beam even closer to the axis of travel This may be done by using the Autoreflection or Gunsight alignment method Instructions for these methods are presented after this procedure Refer to the basic explanation of this method in Chapter 4 System Installation and Alignment of this manual Remove the interferometer from its mount if not already done Select the large aperture on the laser head by rotating the front turret The laser beam should strike the center of the reflector When properly centered the laser beam will be reflected back as two semicircles See Figure 7Y 7 Adjust the Straightness Reflector angularly if using the Straightness Reflector Mount adjust its micrometers until the reflected semicircular dots are centered about the aperture of the beam splitter Place a piece of cardboard with a hole cut in the middle between the beam splitter and the reflector This will help locate these dots The mirror axis of the reflector the optical straight edge should now be aligned parallel to the laser beam and the axis of travel 7Y 10 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness O
5. 0775A Long Range Straightness Optics Installation and Alignment ONE LINEAR and ONE STRAIGHTNESS AXIS ae ENE a ee a ee ree ree Retroreflector i Linear Interferometer y Straightness Interferometer R Sere 1 Position A A Beam Splitter T l l l l l BA T l lt q gt ome a l l l l SPIST M Straightness 5 Interferometer Receiver Position B L j Beam Splitter A Figure 7Y 5 One linear and one straightness axis 2 Supply a rigid mounting surface for both optical components Fine position adjustments of both components will be necessary The Straightness Reflector Mount gives full angular adjustment capability for the reflector 3 The Straightness Interferometer must be located between the laser head or beam directing optic and the Straightness Reflector 4 The measurement beams are returned to the receiver See the previous configuration diagrams 7Y 8 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment Principal alignment steps The principal steps used to align the Straightness optics are listed below followed by a detailed alignment procedure for a specific configuration 1 Thelaser head and optics are mounted in the desired locations and the laser beams are visually aligned parallel to the axes of travel 2 Align the laser beam parallel to the axis of travel by using the
6. 4 120 in Long Range Optics 1 30 m 3 100 feet Dimensions see Figure 7Y 12 on next page Weight Straightness Interferometer 164 grams 5 8 ounces Straightness Reflector 800 grams 28 2 ounces Materials Used Housing Stainless Steel 416 Apertures Plastic Nylon Optics Optical Grade Glass Adhesives Low Volatility Vacuum Grade Optical Efficiency 90 Worst Case User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Specifications 16 Places y 40 0 mm 25 0 mm 1 57 0 98 110 0 mm 4 33 8 0x98 0 mm Aperture Net Weight 800 g 28 2 oz 0 31 x 3 66 Dia Angular Reflector Mane pus 7 9 mm Aperture 0 31 Dia M3x0 5 2 Places pegasse RELELI RRRS POC SSO asicasectsestses Net Weight 164 g 5 8 oz Straightness Interferometer Figure 7Y 12 Agilent 10774A Short Range Straightness optics and Agilent 10775A Long Range Straightness optics User s Manual TY 19 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Specifications 7Y 20 User s Manual
7. Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Introduction Introduction Straightness measures displacement perpendicular tothe axis of intended motion of the optics The straightness measurement optics described in this subchapter are designed for usein a calibrator system such as the Agilent 5529A 55292A More detailed information about the use of these optics can be found in Agilent calibrator system user s documentation Agilent offers two different sets of straightness measuring optics see Figure 7Y 1 e TheAgilent 10774A Short Range Straightness Optics will measure straightness over a range of 0 1 meter to 3 meters 4 inches to 120 inches e TheAgilent 10775A Long Range Straightness Optics will measure straightness over a range of 1 meter to 30 meters 3 feet to 100 feet Agilent 10774A Short Range Straightness Optics Agilent 10775A Long Range Straightness Optics Figure 7Y 1 Straightness optics The Agilent 10774A is available separately or as part of the Agilent 55283A Straightness Measurement Kit which also includes the Agilent 10776A Straightness Accessory Kit the Agilent 10772A Turning Mirror with Mount and the Agilent 10787A Case 7Y 2 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Stra
8. eceivers in this manual for the adjustment procedures of the Receiver c Movethe optic over its full travel range making sure that the receiver signal strength is adequate 0 7 to 1 3 Volts over the entire travel range User s Manual 7Y 11 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment The straightness optics are now aligned There may be further fine adjustment to be done but first make several measurement passes and observe the data If a steady change in the data occurs rather than either a random scattering of numbers or a constant number this indicates misalignment between the axis of travel and the reflector s mirror axis See Figure 7Y 10 for an illustration of this error This error is called slope and must be removed to obtain proper straightness information Autorefl ection method Remove the Straightness nterferometer from its mount surface Place a referenced mirror or gage block between the beam splitter and reflector so that the laser beam strikes its reflective surface Align the referenced mirror until its reflective surface is perpendicular to the axis of travel Select the small aperture on the laser head by rotating the front turret Adjust the laser beam angularly until the beam reflects back on itself from the referenced mirror and is centered on the small aperture of the laser head Make sure that the
9. ee Chapter 5 Laser Heads Chapter 14 Principles of Operation and Chapter 15 Accuracy and Repeatability in this manual g Provide for aligning the optics laser head and receiver s on the machine Alignment targets To help in aligning the straightness interferometers the alignment targets shown in Figure 7Y 3 are included with each Ee Agilent Alignment Target Alignment Target P N 10774 20021 P N 10774 67001 Figure 7Y 3 Alignment Targets for use with straightness interferometers General considerations 1 Choose the optical configuration carefully for best results The diagrams in figures 7Y 4 and 7Y 5 indicate which of the possible configurations are acceptable The diagrams in figures 7Y 6 and TY 7 also indicate system performance based on minimizing power returned to the laser head which can cause instability of the laser output and maximizing power returned to the receiver 7Y 6 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment SINGLE AXIS SYSTEM Straightness Reflector Agilent 10774A or Agilent 10775A Straightness Optics N l Straightness Interferometer lt Agilent 10700A 33 Beam Splitter Agilent 10780C Receiver Figure 7Y 4 Single axis system User s Manual 7Y 7 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 1
10. esponds to the straight edge accuracy and Measurement Accuracy corresponds to the indicator accuracy OPTICAL REFERENCE ACCURACY This can be eliminated by using straight edge mirror reversal techniques Short Range Optics Metric Units Mode 0 15 M micron English Units Mode 0 5 F microinch where M distance of travel of the moving optic in meters and F distance of travel of the moving optic in feet Long Range Optics Metric Units Mode 0 015 M micron English Units Mode 0 5 F microinch where M distance of travel of the moving optic in meters and F distance of travel of the moving optic in feet TY 18 MEASUREMENT ACCURACY Short Range Optics Displayed Value 0 10 pm 0 400 in 10 1500 pm 400 60000 yin Temperature Range 15 26 C 1 0 25um 10 pin 1 0 5um 20 pin 3 5 0 40 C 6 Long Range Optics Displayed Value 0 100 pm 0 4000 pin 100 1500 pm 400 60000 pin Temperature Range 1 0 25um 10 pin 1 0 5um 20 pin 3 5 6 STRAIGHTNESS MEASUREMENT RESOLUTION 0 01 micron 0 4 microinch Short Range Optics 35 micron 14 0 microinches 0 01 micron 4 0 microinch Long Range 3 6 microns Optics 140 microinches STRAIGHTNESS MEASUREMENT RANGE 1 5 mm 0 060 in AXIAL SEPARATION Typical with proper alignment 15 25 C distance between the interferometer and reflector Short Range Optics 0 1 3 m
11. he laser beam goes through the target s hole The interferometer should be mounted perpendicular to the laser beam This may be done by autoreflecting off the front face with a gage block 6 Rotate the interferometer s bezel until the bezel s scribe line See Figure 7Y 8 is oriented perpendicular to the aperture slot on the Straightness reflector Two beams should now exit the interferometer in a plane perpendicular to the aperture slot on the reflector AGILENT 10774A OR HP 10775A STRAIGHTNESS INTERFEROMETER Scribe Line Figure 7Y 8 Agilent 10774A or Agilent 10775A Interferometer scribe line 7 Position the reflector so that the two dots are located over the scribed center line of the reflector housing and the face is square relative tothe incoming beam See Figure 7Y 8 8 Movethe optics to their far end of travel User s Manual 7Y 13 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment 9 Realign the laser beam in this case by using the 33 beam splitter so that the two dots are located over the scribed center line of the reflector housing See Figure 7Y 9 Since the dots will move apart as the optics move you may have to hold a card on each side of the reflector s slot to follow their movement The beam splitter may need to be translated to re center the laser beam in the interferometer target The laser beam should now be aligned paral
12. ightness Optics Squareness and and Parallelism This subchapter describes only the basic measurements using the Agilent 10774A and Agilent 10775A straightness optics F or descriptions of other optics included in the Agilent 10776A kit see the Agilent 5529A 55292A Dynamic Calibrator Measurement Reference Guide Squareness and and Parallelism A squareness measurement consists of two perpendicular straightness measurements made from the same straightness reflector Perpendicularity is achieved using the Agilent 10777A Optical Square Squareness is calculated by adding or subtracting the slopes from each straightness measurement based on a right angle For details see the Agilent 5529A 55292A Dynamic Calibrator Measurenent Reference Guide A parallelism measurement is similar to a squareness measurement except that it does not use an optical square A parallelism measurement consists of two straightness measurements made along the same axis from the same straightness reflector Parallelism is calculated by comparing the slopes of the two straightness measurements F or details see the Agilent 5529A 55292A Dynamic Calibrator Measurement Reference Guide User s Manual 7Y 3 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Principles of Operation Principles of Operation Figure 7Y 2 shows the laser beam path in the straightness optics Initially the two paths from the in
13. lel to the axis of travel POSITIONING OF REFLECTOR Dots located Over Scribed Center line Figure 7Y 9 Initial Positioning of Reflector This ends the Gunsight method alignment method 7Y 14 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment Slope removal The slope should be removed as much as possible by readjusting the Straightness Reflector s mirror axis Slope removal is typically required only for the short range optics because long range alignment is normally more accurate Slope removal can be done by the following procedure 1 Reset the measurement reset the counter to zero with the optics at the near end of travel 2 Movethe optics to the far end of travel and note the last data point see Figure 7Y 10 SLOPE ERROR j Straightness Reflector s Mirror Axis Axis of Travel l Data Points True Distance of Out of Straightness l l I l Figure 7Y 10 Slope Error 3 Adjust the reflector if using the straightness mount adjust the micrometer in the plane of the reflector s aperture slot to cause the straightness measurement to change to the following calculated value x r s d the new value where x r distance between optics at near end of travel S distance of moving optic at far end of travel and d old value read See Figure 7Y 11 for a representa
14. ness e The optical reference accuracy term can be eliminated by rotating the mirror 180 and making another measurement e The slope must be removed manually or in software e Environmental conditions such as temperature changes of the machine or optics vibration and air turbulence can cause errors Errors due to thermal expansion can be minimized by allowing the machine and optics to reach thermal equilibrium before making a measurement The effects of vibration can be reduced by good fixturing averaging successive runs reducing the slew rate and more accurate manual slope removal Air turbulence effects can be minimized by using baffles while thermal gradient effects can be minimized by mixing the air with fans Specifications Specifications describe the device s warranted performance Supplemental characteristics indicated by TYPICAL or NOMINAL are intended to provide nonwarranted performance information useful in applying the device User s Manual 7Y 17 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Specifications Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Specifications ACCURACY Overall accuracy Optical Reference Accuracy Measurement Accuracy This is analogous to the traditional straight edge and indicator method of measuring straightness where Optical Reference Accuracy corr
15. ptics and Agilent 10775A Long Range Straightness Optics Installation and Alignment 5 Install the Straightness Interferometer so that it is centered about the laser beam The interferometer should also be perpendicular to the laser beam This may be done by autoreflecting off the front face with a gage block 6 Rotate the nterferometer s bezel to bring the scribed line parallel to the Straightness Reflector s aperture slot See Figure 7Y 8 Turn the bezel until the dots overlap on the reflector side of the interferometer Use a card to locate the return beam and make the appropriate angular adjustments to the reflector to get the beam back through the interferometer and the beam splitter 7 Adjust the receiver position to center the laser beam in its aperture REFLECTED SEMICIRCULAR BEAMS cia Mirrors Straightness Reflector Reflected Beam Laser Beam Cross Sections Beam From Laser Head Laser Beam Reflected Beam Cross Section Figure 7Y 7 Reflected semicircular beams a If the receiver LED is not on carefully rotate the interferometer s bezel until the LED goes on To maximize the receiver signal attach a fast responding voltmeter or oscilloscope to the receiver test point and receiver case ground Only very slight rotation of the bezel is required typically less than 1 degree b Fine adjust the Interferometer s bezel and Reflector until the receiver test voltage is maximized See Chapter 8 R
16. terferometer to the straightness reflector have the same length As the interferometer or reflector is moved along the axis of travel without lateral motion both of the beams between them will increase or decrease in length at the same rate If either the interferometer or the reflector moves perpendicular to the intended axis of motion the relative lengths of the two beams will change The change in relative path lengths will be X 2D sin 9 2 where D the distance of offset out of straightness o the angle between the two beams leaving the interferometer and X the indicated change in path length Then D X 2 sin 0 2 the angle of the Short Range Interferometer is 1 5916 degrees the angle of the Long Range Interferometer is 0 1592 degrees Thus for short range optics D 36X and for long range optics D 360X 7Y 4 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Principles of Operation STRAIGHTNESS OPTICS BEAM PATHS Mirrors Straightness Reflector Compensated Wollaston Prism N Straightness Interferometer Assembly l Y fat fa aS See lt fatif p fp tf Note Wedge n1 2 has a refractive index of n1 for one plane of polarization and n2 for the other plane Wedges n2 1havethe opposite property a aaa o La Figure 7Y 2 Straightness optics beam paths In practice the
17. tion of this User s Manual 7Y 15 Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Installation and Alignment MANUAL SLOPE REDUCTION Figure 7Y 11 Manual Slope Reduction 4 Reset the measurement again and return the optics to the near end of travel 5 If the signal strength gets too low adjust the laser beam to achieve peak signal strength 6 Repeat steps a through e as often as necessary to make the straightness measurement at both ends of travel to be near zero The alignment procedure for the straightness optics is now complete 7Y 16 User s Manual Chapter 7Y Agilent 10774A Short Range Straightness Optics and Agilent 10775A Long Range Straightness Optics Operation Operation When taking straightness data there will still be some residual slope that has not been removed During data reduction the best fit straight line should be determined and the straightness errors recalculated based on that line Accuracy considerations There are several sources of error under the control of the operator e Thecalibration factor on the interferometer must be used to obtain the correct value Multiply the measured value by the interferometer calibration factor number to get the correct straight
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