Granite Surface Plates

NAVAIR 17-20MD-14

TECHNICAL MANUAL

INSTRUMENT CALIBRATION PROCEDURE MD-14 MD-14

GRANITE SURFACE PLATES

THIS PUBLICATION SUPERSEDES NAVAIR 17-20MD-14 DATED 1 FEBRUARY 2003

DISTRIBUTION STATEMENT C. DISTRIBUTION AUTHORIZED TO U.S. GOVERNMENT AGENCIES AND THEIR CONTRACTORS TO PROTECT PUBLICATIONS REQUIRED FOR OFFICIAL USE OR FOR ADMINISTRATIVE OR MD-14 OPERATIONAL PURPOSES ONLY. OTHER REQUESTS FOR THIS DOCUMENT SHALL BE REFERRED TO MEASUREMENT SCIENCE DEPARTMENT, CORONA DIVISION, NAVAL SURFACE WARFARE CENTER, P.O. BOX 5000, CORONA, CA 92878-5000.

DESTRUCTION NOTICE - FOR UNCLASSIFIED, LIMITED DOCUMENTS, DESTROY BY ANY METHOD THAT WILL PREVENT DISCLOSURE OF CONTENTS OR “RECONSTRUCTION OF THE DOCUMENT.”

PUBLISHED BY DIRECTION OF COMMANDER NAVAL AIR SYSTEMS COMMAND 1 NOVEMBER 2009 NAVAIR 17-20MD-14

LIST OF EFFECTIVE PAGES

The purpose of this list is to identify the pages in this document affected by any technical content changes made since the previous release of the document.

NOTE: On a revised page, with the exception of the Title, the A, and the i pages, the technical changes are indicated by a vertical line in the outer margin of the page.

Page Page Page No. ** Revision* No. ** Revision* No. ** Revision* Title 0 A 0 i 0 1 to 32 0

A-1 0

*Zero in this column indicates an original page. “R” in this column indicates a revised page. **All pages not listed are blank pages.

A NAVAIR 17-20MD-14

TABLE OF CONTENTS

Section Page

1 Introduction and Description ...... 1

2 Equipment Requirements...... 1

3 Preliminary Operations...... 2

4 Calibration Process ...... 5 4.1 Surface Flatness Tests Using an Autocollimator and Mirrors...... 5 4.2 Surface Flatness Calculations...... 7 4.3 Surface Deviation Tests Using a Repeat-O-Meter ...... 12

Navy Calibration Checklist...... 29

Appendix A: Representative Test Instruments ...... A-1

ILLUSTRATIONS

Figure Page

1 Initial Surface Flatness Test Configuration, Autocollimator Method...... 3 2 Sequential Positions of the Autocollimator and Corner Mirror ...... 6 3 Sample Measurement Line Tie-In Chart...... 9 4 Sample Measurement Line Variation Chart...... 11

TABLES

Table Page

1 Calibration Description...... 1 2 Equipment Requirements...... 2

i NAVAIR 17-20MD-14

SECTION 1

INTRODUCTION AND DESCRIPTION

1.1 This procedure describes the calibration of Granite Surface Plates. Surface plates that can be calibrated using this procedure include, but are not limited to, the models/sizes listed in Appendix A. The surface plate being calibrated is referred to herein as the TI (Test Instrument).

1.2 All comments concerning this procedure should be directed to the Measurement Science Department, Corona Division, Naval Surface Warfare Center, P.O. Box 5000, Corona, CA 92878-5000.

1.3 This procedure includes tests of essential performance parameters only. Any malfunction noticed during calibration, whether specifically tested for or not, should be corrected.

Table 1. Calibration Description TI Performance Test Characteristics Specifications Method Surface flatness Size range: 12 x 12 in. up to Surface deviations are measured 72 x 144 in. with an autocollimator and two mirrors in seconds of arc along Tolerances: the specified datum lines set up Line tie-in: 25 to 100 microinches, on the TI surface. The deviation depending on the grade or 10% of basic values are then converted to tolerance, whichever is greater microinches to determine if the Basic: 50 to 4400 microinches end point values meet the line depending on the size and grade tie-in tolerance and if the station Repeat reading: 25 to 280 microinches, values along each datum line are depending on the size and grade within the basic tolerance. Alternatively, the surface deviations are measured directly with a repeat-o-meter in microinches along the specified datum lines to determine if the values are within the repeat reading tolerance.

SECTION 2

EQUIPMENT REQUIREMENTS

NOTES

Minimum use specifications are the principal parameters required for performance of the calibration, and are included to assist in the selection of alternate equipment, which may be used at the discretion of the using laboratory. Satisfactory performance of alternate items shall be verified prior to use. All applicable equipment must bear evidence of current calibration.

The instruments utilized in this procedure were selected from those known to be available at Navy calibration facilities and the listing by make or model number carries no implication of preference, recommendation, or approval for use by other agencies. It is recognized that equivalent equipment produced by other manufacturers may be capable of equally satisfactory performance in this procedure.

1 NAVAIR 17-20MD-14

Table 2. Equipment Requirements Item Minimum Use Calibration Specifications Equipment 2.1 Autocollimator with Minimum range: 2 minutes Davidson Optronics D-638-105 adjustable base Uncertainty: ±0.5 sec of arc Hilger-Watts TA-1 or TA-51 with TA-54 Leitz ABCAA, or AADHM/GAATN with AADFH 2.2 Adjustable corner mirror Flatness: 1/4 fringe Davidson Optronics D-615 2.3 Adjustable movable mirror Flatness: 1/4 fringe Davidson Optronics D-616 2.4 Mirror carriage Pad spacing: 4.0 in. Davidson Optronics D-291 or Uncertainty: NA Metrology Engineering Center D-254-A1 2.5 Mirror carriage Pad spacing: 5.0 in. Davidson Optronics D-292 or Uncertainty: NA Metrology Engineering Center D-254-A2 2.6 Steel straightedge Length: (Minimum) equal to the diagonal length L.S. Starrett 380-36, 380-48, of the TI 380-72 and 380-96 as applicable or equivalent 2.7 Toolmakers steel clamp Capable of clamping the straight edge to the TI Brown & Sharpe 599-754-8; or (2 ea.) Local supply 2.8 Repeat-O-Meter Range: ±0.001 in. Rahn Repeat-O-Meter Uncertainty: ±0.00001 in.

SECTION 3

PRELIMINARY OPERATIONS

3.1 Clean the surfaces of the granite surface plate using an approved cleaner; or a mild nonabrasive detergent and water, rinse with clean water and wipe dry with soft paper or cloth towels.

3.2 Ensure that the temperature in the calibration area is within 68° to 76 °F. The humidity should be controlled so as to not exceed 45% RH.

3.3 Ensure that the TI is shielded from sources of radiant heat, and that the ambient temperature is stable to within ±2 °F per hour.

3.4 If the autocollimator (item 2.1) and mirrors (items 2.2, 2.3) are to be used to calibrate the TI, set up the equipment on the TI surface as shown in Figure 1.

2 NAVAIR 17-20MD-14

2.7 CLAMP

NORTH

2.6 2.3 STEEL MOVABLE STRAIGHTEDGE MIRROR

WEST EAST TI

STEEL 2.7 STRAIGHTEDGE CLAMP FACE

2.1 AUTOCOLLIMATOR

SOUTH MFG'S NAMEPLATE 2.2 W/SER. NO. CORNER MIRROR

Figure 1. Initial Surface Flatness Test Configuration, Autocollimator Method

NOTE

The test configuration of Figure 1 is required only for an initial acceptance test and calibration, or if test results using the Repeat-O-Meter are suspect. In all other situations, skip to step 3.7 for the preparations involving the Repeat-O-Meter method.

3.5 If the autocollimator method is selected, prepare for the TI calibration as follows:

3.5.1 Referring to Figure 1, lay out and mark eight datum lines for the measurements to follow. The eight datum lines are the four perimeter lines East, West, North and South, the two diagonal lines NW-SE and NE-SW and the two center lines N-S and E-W.

NOTES

The perimeter lines must lie within 2 inches of the applicable edge for TIs 24 x 24 in. up to 36 x 48 in. in size, or within 4 inches for TIs larger than 36 x 48 in.

The stations, or points at which measurements are taken, are marked in increments equal to the pad spacing of the mirror carriage.

3 NAVAIR 17-20MD-14

NOTE

When stepping off the profile lines, rigid triangulation shall be adhered to and the intersection points of all lines shall fall within 0.3 inch diameter circle. Adjustable pad spacing sleds may be required for the diagonal profile runs if fixed pad spacing sleds do not meet the requirements. The minimum number of steps per profile lines shall be 6; the maximum step spacing shall be 12 inches. The contract probe or the two pads on the sled which trace the profile line shall be 0.375 inch diameter with a sharp (not beveled) edge. The outrigger pad may be 0.375 inch diameter or dimensioned 0.4 x 0.5 inches for uniform pad wear.

3.5.2 Clean the surface of the steel straightedge (item 2.6), as required using an approved cleaner; or a mild nonabrasive detergent and water, rinse with clean water and wipe dry with soft paper or cloth towels.

3.5.3 Allow the TI and equipment to stabilize at the ambient temperature for a minimum of one hour.

3.5.4 Starting from the center, mark off the top face of the steel straightedge along the edge in increments equal to the pad spacing of the mirror or mirror carriage, as applicable, being used in the calibration. Identify the center line of the steel straightedge so that positioning of the steel straightedge with the center of the line under test is simplified. See Figure 1.

3.5.5 Position the steel straightedge on the TI so that the FACE of the steel straightedge is parallel to and approximately 1/2 the diameter of the movable mirror spacing pads from the NW to SE diagonal line and ensure that the center line of the steel straightedge is located at the center of the TI as shown in Figure 1. This is required so that the center of the mirror pads will pass along the line under test. Secure the steel straightedge with clamps (item 2.7) or other means as appropriate.

3.5.6 Set the autocollimator power switch to on. Position each adjustable mirror, in turn, in the front of the autocollimator, and perform the necessary operations (leveling the autocollimator, adjusting the reflecting surface of the mirrors, etc.) to obtain auto collimation in azimuth and elevation from the mirrors. Square the mirrors in both planes.

3.5.7 Position the autocollimator and adjustable mirrors initially as shown in Figure 1. Ensure that the autocollimator is set up for measurements in elevation.

3.5.8 Adjust the position of the autocollimator and corner mirror as required so that the reticule image reflected from the movable mirror remains approximately centered in the field of view when the movable mirror is moved along the edge of the steel straightedge to the calibration station nearest to the corner mirror. When the adjustment is satisfactory, reposition the movable mirror at the calibration station in the NW corner of the TI.

NOTE

Set the autocollimator micrometer at any half minute setting. Example: 3’ 30.0”, 4’ 30.0”, 5’ 30.0”, etc. at the beginning of each line measurement.

3.6 Wipe the surface plate along the leading edge of the steel straight edge with a lint free cloth to ensure that no dust particles are present. This may be required periodically on each line throughout the calibration.

3.7 If the Repeat-O-Meter method is selected (see the Note under Figure 1), prepare for the TI calibration as follows:

3.7.1 Perform step 3.5.1

3.7.2 Position the Repeat-O-Meter (item 2.8) in the center of the TI and zero the indicator.

4 NAVAIR 17-20MD-14

SECTION 4

CALIBRATION PROCESS

NOTE

Unless otherwise specified, verify the results of each test and take corrective action whenever the test requirement is not met, before proceeding.

4.1 SURFACE FLATNESS TESTS USING AN AUTOCOLLIMATOR AND MIRRORS

NOTE

If the autocollimator and mirrors method is not required (see the Note following Figure 1) or if the size of the TI is 24 x 24 inches or less, skip directly to Section 4.3.

4.1.1 Ensure that the preparations of steps 3.4 through 3.6 have been completed.

4.1.2 Position the in-line feet of the movable mirror mount so that they are in contact with the steel straight edge, and the center of the rear foot is aligned with the point of line intersection (zero station) at the NW corner of the TI (refer to Figure 1). Determine and note the average of 3 autocollimator indications. Approach settings in the direction of increasing indications. Record the average autocollimator indication to the nearest 0.1 second of arc in column (2) of the calibration worksheet. Drop the minutes and record only the seconds to the nearest 0.1 second of arc.

NOTE

As shown in Figure 1, it may occur that the line to be measured may not be divisible in equal increments corresponding to the pad spacing of the movable mirror available. In such a case, the rear foot of the mirror is aligned at the 0 station (point of line intersection) and the indication obtained will be noted as the station 1 measurement. The subsequent station measurements will be obtained with the leading foot of the mirror mount aligned at the indicated station points. The last measurement will be performed with the leading foot of the mirror mount at the designated end of the line (point of line intersection) to obtain an equal number of measurements. The average of three (3) separate autocollimator indications is obtained with the rear foot of the movable mirror at the zero station to ascertain repeatability. Thereafter, obtain only one indication at the remaining stations.

4.1.3 Perform a measurement and record in column (2) of the applicable work sheet one (1) autocollimator indication at each of the remaining calibration stations on the NW to SE diagonal line. Approach all settings in the direction of increasing indications. Record the autocollimator seconds indications only, to nearest 0.1 second.

4.1.4 After the measurement is performed at the last calibration station on the line, slide the movable mirror back to the first calibration station and obtain another autocollimator indication. Verify that the indication is within ±1.0 second of arc of the first indication noted in step 4.1.2; if not, perform steps 4.1.2 through 4.1.4 until agreement to ±1.0 second of arc is achieved to verify autocollimator-mirror system repeatability.

4.1.5 Reposition the equipment as required performing the measurements of each of the remaining lines. Perform the measurements for each line as described in steps 4.1.1 through 4.1.4, except recording only one autocollimator indication at station No.1.

5 NAVAIR 17-20MD-14

NOTES

Suggested sequential positions of the autocollimator are shown in Figure 2. For example: with the autocollimator in position 1, the NW to SE diagonal line, the N to S center line, and the east N to S perimeter line can be measured. With the autocollimator in position 2, the NE to SW diagonal line and the west N to S perimeter line can be measured.

The autocollimator is shown as item 2.1 and the corner mirror as item 2.2 in Figure 2.

NORTH 2.2 POS 8

POS 4 2.2 POS 9 WEST EAST

POS 3

POS 1 POS 2 2.1

2.2 2.2 2.2

POS 7 SOUTH POS 5 POS 6

Figure 2. Sequential Positions of the Autocollimator and Corner Mirror

NOTE

The direction of measurements must be performed as shown in Figure 2 and as specified on the worksheets to avoid erroneous tie-line data. Ensure the correct sign (+ or -) for increasing or decreasing indications by raising the leading foot of the movable mirror and noting the direction of the micrometer dial, sighting through the corner mirror.

4.1.6 Refer to the following table as an aid in selecting the correct autocollimator and corner mirror positions for the eight measurement lines.

6 NAVAIR 17-20MD-14

Measurement Line Positioning APPROXIMATE Corner Mirror Measurement Line Autocollimator Position Position Diagonal Line NW-SE 1 or 4 5 Perimeter Line East N-S 1 or 4 5 Center Line N-S 1 or 2 6 Diagonal Line NE-SW 2 or 3 7 Perimeter Line West N-S 2 or 4 7 Perimeter Line North E-W 1 or 2 8 Center Line E-W 1 or 2 9 Perimeter Line South E-W 2 or 4 7

4.2 SURFACE FLATNESS CALCULATIONS

NOTE

For all measurement lines, column (3) worksheet arc sec. values are obtained by subtracting the autocollimator indications for the first station in column (2) from the indication at each subsequent station and recording the result opposite that station in column (3). The above rule holds if the autocollimator is a Davidson Optronics D-638 or D-638-105, D838-105, or a Hilger & Watts TA-51 or TA-71. However, if the autocollimator is a Hilger & Watts TA-1 or Leitz ABCAA or AADHM, the sign of the result must be reversed before recording it in column (3).

4.2.1 Diagonal lines NW to SE and NE to SW.

4.2.1.1 Subtract the value for station No. 1 from each of the remaining stations, reversing the sign of the result, if necessary, per the above Note. Record the final result opposite the applicable station in column (3). See sample calibration worksheets No. 1 and No. 2, observing the direction indicated.

4.2.1.2 Determine the algebraic, cumulative sum of the values recorded in column (3) for each station and record the result opposite the applicable station in column (4).

4.2.1.3 Determine the correction factor by dividing the final station value in column (4) by the final station number. Record the result as the measurement line correction factor at the top of each worksheet.

NOTE

As an example, referring to sample calibration worksheet No. 1, the Station No. 20 value is -28.0. Dividing -28.0 by 20, the number of stations, the result, -1.4, is the correction factor.

4.2.1.4 Reverse the sign of the value in column (4) opposite the midstation and record it opposite the same station in column (5). When working up column (5) from the midstation algebraically add the correction factor obtained in step 4.2.1.3 cumulatively at each station. Working down from the midstation, algebraically subtract the correction factor obtained in step 4.2.1.3 cumulatively at each station. (Each result obtained is the cumulative correction factor for the station.) Record the results in column (5). Refer to the sample worksheets.

4.2.1.5 Algebraically add the value in column (4) and (5) opposite each station, and record the results in column (6). (The result obtained is the angular displacement from the datum plane. The datum plane is that plane in which the center point of the TI surface lies and which is parallel to the lines containing the end points of each diagonal line. The datum plane lies above and is parallel to the base plane).

4.2.2 Perimeter lines North, East, South and West.

7 NAVAIR 17-20MD-14

4.2.2.1 Subtract the value for station No. 1 from each of the remaining stations, reversing the sign of the result, if necessary, per the Note at the beginning of this subsection. Record the final result opposite the applicable station in column (3). See sample calibration worksheets No. 3 through No.6, observing the direction indicated.

4.2.2.2 Determine the algebraic, cumulative sum of the values recorded in column (3) for each station and record the result opposite the applicable station in column (4).

4.2.2.3 Enter the following values on worksheets No. 3 through No. 6 in columns (5) and (6) opposite the zero station:

4.2.2.3.1 North and East Perimeter Lines: NE end value of the NE to SW Diagonal Line.

4.2.2.3.2 South Perimeter Line: SE end value of the NW to SE Diagonal Line.

4.2.2.3.3 West Perimeter Line: NW end value of the NW to SE Diagonal Line.

4.2.2.4 Enter the following values on worksheets No. 3 through No. 6 in column (6) opposite the final station:

4.2.2.4.1 North Perimeter Line: NW end value of the NW to SE Diagonal Line.

4.2.2.4.2 East Perimeter Line: SE end value of the NW to SE Diagonal Line.

4.2.2.4.3 South and West Perimeter Lines: SW end value of the NE to SW Diagonal Line.

4.2.2.5 Determine the correction factor by algebraically subtracting the final station value in column (4) from the same station value in column (6). Enter the result opposite the final station in column (5) Algebraically subtract the result from the value opposite the zero station in column (5). Divide the resulting value by the number of stations in the column. Record the final result as the measurement line correction factor at the top of each worksheet.

NOTE

As an example referring to sample calibration worksheet No. 3, the Station No. 16 value, column (4) is -19.9. Subtracting -19.9 from the column (6) value yields -3.6 - (-19.9) or +16.3. Subtracting +16.3 from the column (5) value yields -5.4 -(+16.3) or -21.7. Dividing -21.7 by 16 yields - 1.4, the correction factor.

4.2.2.6 Beginning at the final station in column (5), algebraically add the correction factor obtained in step 4.2.2.5 to each station in turn, cumulatively up column (5). Refer to sample calibration worksheets No. 3 through No. 6.

4.2.2.7 Algebraically add the values in columns (4) and (5) opposite each station and record the result in column (6).

4.2.3 Center Lines East to West and North to South.

4.2.3.1 Subtract the value for station No.1 from each of the remaining stations, reversing the sign of the result, if necessary, per the Note at the beginning of the subsection. Record the final result opposite the applicable station in column (3). See sample calibration worksheet No. 7 and No. 8, observing the direction indicated.

4.2.3.2 Determine the algebraic cumulative sum of the values recorded in column (3) for each station and record the result opposite the applicable station in column (4).

NOTE

Column (6) is divided into two sub-columns: (6a) on the left and (6b) on the right of calibration worksheets No. 7 and No. 8.

4.2.3.3 Enter the following values on worksheets No. 7 and No. 8 in columns (5) and (6a) opposite the ZERO station:

4.2.3.3.1 East to West Center Line: Midpoint value of the East Perimeter Line; Copy from worksheet No. 4 column (6).

8 NAVAIR 17-20MD-14

4.2.3.3.2 North to South Center Line: Midpoint value of the North Perimeter line; Copy from worksheet No. 3 column (6).

4.2.3.4 Enter the following values on worksheets No. 7 and No. 8 in column (6a) opposite the final station:

4.2.3.4.1 East to West Center Line: Midpoint value of the West Perimeter Line; Copy from worksheet No. 6 column (6).

4.2.3.4.2 North to South Center Line: Midpoint value of the South Perimeter Line; Copy from worksheet No. 5 column (6).

4.2.3.5 Determine the correction factor by algebraically subtracting the final station value in column (4) from the same station value in column (6a). Enter the result opposite the final station in column (5). Algebraically subtract the result from the value opposite the ZERO station in column (5). Divide the result by the number of stations in the column. Record the final result as the measurement line correction factor at the top of each worksheet.

NOTE

As an example, referring to sample calibration worksheet No.7, the Station No. 16 value, column (4) is -8.0. Subtracting -8.0 from the column (6a) value yields -5.2 - (-8.0) or +2.8. Subtracting +2.8 from the column (5) value yields -6.6 - (+2.8) or -9.4. Dividing -9.4 by 16 yields -0.6, the correction factor.

4.2.3.6 Beginning at the final station in column (5), algebraically add the correction factor obtained in step 4.2.3.5 to each station in turn, cumulatively up column (5). Refer to sample calibration worksheets No. 7 and No. 8.

4.2.3.7 Algebraically add the values in columns (4) and (5) opposite each station and record the result in column (6a).

4.2.3.8 Change the sign of the value opposite the midpoint station. Add the resulting value to each station value in column (6a) and record the result opposite that station in column (6b).

4.2.4 Measurement Line Tie-In Verification

4.2.4.1 Prepare a chart of the TI measurement lines, listing the midpoint and end point values. An example of a chart is provided below as Figure 3, based on sample calibration worksheet No. 1 through No. 8 values.

NORTH +1.1

-3.6 +1.1 -5.4

WEST -4.7 -5.2 0 -6.6 -6.1 EAST

-5.3 +2.4 -3.6

+2.4 MFG'S NAMEPLATE SOUTH

Figure 3. Sample Measurement Line Tie-In Chart

4.2.4.2 Using the chart prepared in step 4.2.4.1, note the tie-in values where perimeter and diagonal measurement lines meet at a common end point as recorded in column (6) of the worksheet, or where perimeter and center measurement lines meet at a common mid point as recorded in column (6) or (6b) of the worksheet.

9 NAVAIR 17-20MD-14

4.2.4.3 Note the line tie-in points with the greatest differences. Convert the greatest differences to microinches.

NOTES

The conversion factor is the product of the sine of one arc second (0.00000485) and the distance between the base pads of the movable mirror. If the pad to pad distance is 4 inches, the factor is 0.00000485 x 4 = 0.0000194.

As an example, the largest difference noted in Figure 3 is -0.5 at the East and West mid points. Using the above conversion factor, -0.5 x 0.0000194 = -0.0000097, or -9.7 microinches. This result can be rounded off to the nearest whole number: -10 microinches.

4.2.4.4 Verify that the maximum difference at the line tie-in points does not exceed the tolerance specified for the TI grade in the Line Tie-In Tolerances table or 10% of the tolerance specified for the TI grade and size in the Flatness Tolerance for Autocollimator Calibrations table, whichever of the two values is greater.

Line Tie-In Tolerances Tolerance Limits TI Grade (μ in) AA (Laboratory) 25 A (Inspection) 25 B (Tool Room) 100

Flatness Tolerance for Autocollimator Calibrations TI Size Tolerance Limits Grade AA Grade A Grade B Width Length Laboratory Inspection Tool Room (in) (in) (μ in) (μ in) (μ in) 24 24 75 150 300 24 36 100 200 400 24 48 150 300 600 36 36 150 300 600 36 48 200 400 800 36 60 200 500 1000 36 72 300 600 1200 48 48 200 400 800 48 60 300 600 1200 48 72 350 700 1400 48 96 500 1000 2000 72 144 1100 2200 4400

4.2.4.5 If one or more line tie-in differences exceed the applicable TI tolerance limits, find the source of the error and/or repeat the measurements described in steps 4.2.1 through 4.2.3 to verify the correct line tie-in differences.

4.2.5 Final Worksheet Calculations

4.2.5.1 Find the lowest (most negative) value for all the stations in the column (6) among all of the two diagonal and four perimeter measurement lines and all the stations in column (6b) among the two center lines. Reverse the sign of the above value.

10 NAVAIR 17-20MD-14

NOTE

As an example, the highest negative value listed on the sample worksheets is the value -6.9 in column (6) for station No. 4 on the East Perimeter Line. The above value is changed to +6.9 for use in the worksheet calculations.

4.2.5.2 Add the positive value obtained in step 4.2.5.1 to each station value in column (6) or (6b), as applicable. Record the resulting values in column (7) of each worksheet.

NOTE

The values in column (7) represent the displacement of each station from the true base plane. The true base plane is parallel to the datum plane; the true base plane also contains the lowest measurement point.

4.2.5.3 Convert each station value in column (7) to microinches and record the result opposite that station in column (8), and on the calibration checklist, the displacement from the base plane.

NOTE

As an example, using the conversion factor 0.0000194 established in the first Note of step 4.2.4.3, the largest value, +9.3 arc seconds at station No. 7 or No. 8, column (7), sample worksheet No. 5 for the South Perimeter line, converts to +9.3 x 0.0000194 or +180 microinches, rounded off to the nearest microinch.

4.2.5.4 Verify that each station value in column (8) of the worksheets is within the flatness tolerance limits listed in the Flatness Tolerances for Autocollimator Calibrations table for the size and grade of the TI being calibrated.

4.2.5.5 If required, prepare a chart of the TI measurement lines, entering the data from column (8) for the midpoints and endpoints, as shown in Figure 4 below. The values shown are based on sample calibration worksheet No. 1 through No. 8 values; more values can be added between the midpoints and endpoints, if necessary, to depict the surface variations of the TI.

NORTH +155 +64 +155 +29

WEST +33 + 43 +134 +16 +6 EAST

+31 +180 +66 +180 SOUTH

Figure 4. Sample Measurement Line Variation Chart

4.2.5.6 Unless other measurements are to be performed, set the autocollimator power switch to off, disconnect and secure the equipment.

11 NAVAIR 17-20MD-14

4.3 SURFACE DEVIATION TESTS USING A REPEAT-O-METER

NOTE

The Repeat-O-Meter method is recommended for the calibration of all TIs and must be employed for a TI of 24 x 24 in. or smaller size. However, it should be noted that the Repeat-O-Meter measures surface deviations which are generally much smaller than flatness deviations measured by an autocollimator and mirrors. Therefore, if Repeat-O-Meter results are suspect, the autocollimator method should be used to verify the true TI out of flatness.

4.3.1 Ensure that the preliminary preparations of steps 3.6 and 3.7 have been completed.

4.3.2 Using the 0.375 inch stem indicator with the Repeat-O-Meter, position the Repeat-O-Meter in the center of the surface plate (intersection of diagonal and center line midpoints). ZERO the Repeat-O-Meter indicator.

4.3.3 Scan the first measurement line with the Repeat-O-Meter. Determine the absolute difference between the largest minus (-) indication and the largest plus (+) indication. Record the result on the calibration checklist as the TI surface deviation for the repeat readings.

4.3.4 Verify that the surface deviation (step 4.3.3) is within the tolerance limits listed in the following table below for the size and grade of the TI being calibrated.

Flatness Tolerances for Repeat Reading Calibrations Tolerance Limits TI Size Diagonal Length GRADE AA GRADE A GRADE B (in) LABORATORY INSPECTION TOOL ROOM (μ in) (μ in) (μ in) All sizes * 25 50 100 Up to 30 ** 35 60 110 31 to 60 ** 45 70 120 61 to 90 ** 60 80 160 91 to 120 ** 75 100 200 21 to 150 ** 90 120 240 51 and larger 100 140 280 * When tolerance limits are specified by the manufacturer. ** When tolerance limits are unspecified.

4.3.5 Perform steps 4.3.3 and 4.3.4 for each remaining TI measurement line to be scanned by the Repeat-O-Meter.

4.3.6 If the TI is out-of-tolerance along any of the measurement lines, calibrate the TI using an autocollimator and mirrors to verify true surfaces flatness.

4.3.7 Unless other measurements are to be performed, disconnect and secure the equipment.

12 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 1

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.1.3 correction factor: -1.4 GRADE B TOLERANCE 1400 μ in

DIAGONAL LINE, NORTHWEST TO SOUTHEAST (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------3.6 -3.6 +3.3 +64

1 36.5 0 0 -2.2 -2.2 +4.7 +91

2 36.0 -0.5 -0.5 -0.8 -1.3 +5.6 +109

3 35.0 -1.5 -2.0 +0.6 -1.4 +5.5 +107

4 35.2 -1.3 -3.3 +2.0 -1.3 +5.6 +109

5 35.5 -1.0 -4.3 +3.4 -0.9 +6.0 +116

6 35.6 -0.9 -5.2 +4.8 -0.4 +6.5 +126

7 35.5 -1.0 -6.2 +6.2 0 +6.9 +134

8 35.0 -1.5 -7.7 +7.6 -0.1 +6.8 +132

9 35.5 -1.0 -8.7 +9.0 +0.3 +7.2 +140

10 34.8 -1.7 -10.4 +10.4 0 +6.9 +134

11 35.0 -1.5 -11.9 +11.8 -0.1 +6.8 +132

12 35.2 -1.3 -13.2 +13.2 0 +6.9 +134

13 35.3 -1.2 -14.4 +14.6 +0.2 +7.1 +138

14 34.9 -1.6 -16.0 +16.0 0 +6.9 +134

15 34.6 -1.9 -17.9 +17.4 -0.5 +6.4 +124

16 34.2 -2.3 -20.2 +18.8 -1.4 +5.5 +107

17 35.5 -1.2 -21.4 -20.2 -1.2 +5.7 +111

18 34.9 -1.6 -23.0 +21.6 -1.4 +5.5 +107

19 34.5 -2.0 -25.0 +23.0 -2.0 +4.9 +95

20 33.5 -3.0 -28.0 +24.4 -3.6 +3.4 +66

13 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 2

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.1.3 correction factor: -1.8 GRADE B TOLERANCE 1400 μ in

DIAGONAL LINE, NORTHEAST TO SOUTHWEST (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------5.4 -5.4 +1.5 +29

1 36.6 0 0 -3.6 -3.6 +3.3 +64

2 35.4 -1.2 -1.2 -1.8 -3.0 +3.9 +76

3 35.4 -1.2 -2.4 -0.1 -2.5 +4.4 +85

4 35.2 -1.4 -3.8 +1.7 -2.1 +4.8 +93

5 35.5 -1.1 -4.9 +3.5 -1.4 +5.5 +107

6 35.7 -0.9 -5.8 +5.2 -0.6 +6.3 +122

7 35.0 -1.6 -7.4 +7.0 -0.4 +6.5 +126

8 35.0 -1.6 -9.0 +8.8 -0.2 +6.7 +130

9 35.4 -1.2 -10.2 +10.5 +0.3 +7.2 +140

10 34.5 -2.1 -12.3 +12.3 0 +6.9 +134

11 34.4 -2.2 -14.5 +14.1 -0.4 +6.5 +126

12 34.5 -2.1 -16.6 +15.8 -0.8 +6.1 +118

13 34.5 -2.1 -18.7 +17.6 -1.1 +5.8 +113

14 34.8 -1.8 -20.5 +19.4 -1.1 +5.8 +113

15 34.2 -2.4 -22.9 +21.1 -1.8 +5.1 +99

16 34.2 -2.4 -25.3 +22.9 -2.4 +4.5 +87

17 34.2 -2.4 -27.7 +24.7 -3.0 +3.9 +76

18 34.8 -1.8 -29.5 +26.4 -3.1 +3.8 +74

19 34.2 -2.4 -31.9 +28.2 -3.7 +3.2 +62

20 33.2 -3.4 -35.3 +30.0 -5.3 +1.6 +31

14 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 3

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.2.5 correction factor: -1.4 GRADE B TOLERANCE 1400 μ in

NORTH PERIMETER LINE, EAST TO WEST (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------5.4 -5.4 +1.5 +29

1 30.5 0 0 -4.0 -4.0 +2.9 +56

2 29.7 -0.8 -0.8 -2.7 -3.5 +3.4 +66

3 30.5 0 -0.8 -1.3 -2.1 +4.8 +93

4 30.3 -0.2 -1.0 0 -1.0 +5.9 +114

5 30.2 -0.3 -1.3 +1.4 +0.1 +7.0 +136

6 29.9 -0.6 -1.9 +2.7 +0.8 +7.7 +149

7 29.0 -1.5 -3.4 +4.1 +0.7 +7.6 +147

8 29.5 -1.0 -4.4 +5.5 +1.1 +8.0 +155

9 28.8 -1.7 -6.1 +6.8 +0.7 +0.7 +147

10 28.6 -1.9 -8.0 +8.2 +0.2 +7.1 +138

11 28.7 -1.8 -9.8 +9.5 -0.3 +6.6 +128

12 28.6 -1.9 -11.7 +10.9 -0.8 +6.1 +118

13 28.4 -2.1 -13.8 +12.2 +1.6 +5.3 +103

14 28.5 -2.0 -15.8 +13.6 -2.2 +4.7 +91

15 29.0 -1.5 -17.3 +14.9 -2.4 +4.5 +87

16 27.9 -2.6 -19.9 +16.3 -3.6 +3.3 +64

15 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 4

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.2.5 correction factor: -0.4 GRADE B TOLERANCE 1400 μ in

EAST PERIMETER LINE, NORTH TO SOUTH (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------5.4 -5.4 +1.5 +29

1 33.5 0 -0 -5.0 -5.0 +1.9 +37

2 32.1 -1.4 -1.4 -4.6 -6.0 +0.9 +17

3 32.5 -1.0 -2.4 -4.2 -6.6 +0.3 6

4 32.8 -0.7 -3.1 -3.8 -6.9 0 0

5 33.4 -0.1 -3.2 -3.4 -6.6 +0.3 +6

6 33.2 -0.3 -3.5 -2.9 -6.4 +0.5 +10

7 33.5 0 -3.5 -2.5 -6.0 +0.9 +17

8 34.0 +0.5 -3.0 -2.1 -5.1 +1.8 +35

9 34.2 -0.7 -2.3 -1.7 -4.0 +2.9 +56

10 33.5 0 -2.3 -1.3 -3.6 +3.3 +64

16 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 5

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.2.5 correction factor: -1.8 GRADE B TOLERANCE 1400 μ in

SOUTH PERIMETER LINE, EAST TO WEST (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------3.6 -3.6 +3.3 +64

1 36.4 0 0 -1.8 -1.8 +5.1 +99

2 35.0 -1.4 -1.4 +0.1 -1.3 +5.6 +109

3 35.6 -0.8 -2.2 +1.9 -0.3 +6.6 +128

4 35.5 -0.9 -3.1 +3.7 -0.6 +7.5 +146

5 35.1 -1.3 -4.4 +5.5 +1.1 +8.0 +155

6 35.3 -1.1 -5.5 +7.4 +1.9 +8.8 +171

7 35.1 -1.3 -6.8 +9.2 +2.4 +9.3 +180

8 34.6 -1.8 -8.6 +11.0 +2.4 +9.3 +180

9 34.0 -2.4 -11.0 +12.8 +1.8 +8.7 +169

10 33.5 -2.9 -13.9 +14.7 +0.8 +7.7 +149

11 33.5 -2.9 -16.8 +16.5 -0.3 +6.6 +128

12 33.3 -3.1 -19.9 +18.3 -1.6 +5.3 +103

13 33.3 -3.1 -23.0 +20.1 -2.9 +4.0 +78

14 33.4 -3.0 -26.0 +22.0 -4.0 +2.9 +56

15 34.0 -2.4 -28.4 +23.8 -4.6 +2.3 +45

16 33.9 -2.5 -30.9 +25.6 -5.3 +1.6 +31

17 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 6

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.2.5 correction factor: -0.5 GRADE B TOLERANCE 1400 μ in

WEST PERIMETER LINE, NORTH TO SOUTH (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------3.6 -3.6 +3.3 +64

1 36.0 0 0 -3.1 +3.1 +3.8 +74

2 34.6 -1.4 -1.4 -2.6 -4.0 +2.9 +56

3 35.5 -0.5 -1.9 -2.0 -3.9 +3.0 +58

4 34.7 -1.3 -3.2 -1.5 -4.7 +2.2 +43

5 35.0 -1.0 -4.2 -1.0 -5.2 +1.7 +33

6 34.5 -1.5 -5.7 -0.5 -6.2 +0.7 +14

7 35.9 0 -5.8 0 -5.8 +1.1 +21

8 36.0 0 -5.8 +0.6 -5.2 +1.7 +33

9 36.0 0 -5.8 +1.1 -4.7 +2.2 +43

10 34.9 -1.1 -6.9 +1.6 -5.3 +1.6 +31

18 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 7

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.3.5 correction factor: -0.6 GRADE B TOLERANCE 1400 μ in

CENTER LINE, EAST TO WEST (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------6.6 -6.6 -6.1 +0.8 +16

1 31.7 0 0 -6.0 -6.0 -5.5 +1.4 +27

2 32.4 +0.7 +0.7 -5.4 -4.7 -4.2 +2.7 +52

3 32.1 +0.4 +1.1 -4.8 -3.7 -3.2 +3.7 +72

4 32.5 +0.8 +1.9 -4.3 -2.4 -1.9 +5.0 +97

5 32.0 +0.3 +2.2 -3.7 -1.5 -1.0 +5.9 +114

6 31.5 -0.2 +2.0 -3.1 -1.1 -0.6 +5.9 +114

7 31.5 -0.2 +1.8 -2.5 -0.7 -0.2 +6.7 +130

8 31.3 -0.4 +1.4 -1.9 -0.5 0 +6.9 +134

9 31.3 -0.4 +1.0 -1.3 -0.3 +0.2 +7.1 +138

10 30.3 -1.4 -0.4 -0.7 -1.1 -0.6 +6.3 +122

11 30.8 -0.9 -1.3 -0.1 -1.4 -0.9 +6.0 +116

12 30.3 -1.4 -2.7 +0.5 -2.2 -1.7 +5.2 +101

13 30.0 -1.7 -4.4 +1.0 -3.4 -2.9 +4.0 +78

14 30.7 -1.0 -5.4 +1.6 -3.8 +3.3 +3.6 +70

15 30.4 -1.3 -6.7 +2.2 -4.5 -4.0 +2.9 +56

16 30.4 -1.3 -8.0 +2.8 -5.2 -4.7 +2.2 +43

19 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 8

DATE 7/20/78 TEST INST. MFG. COLLINS MICROFLAT OPERATOR Martin, S. SERIAL NO. 24966 TEST INST. Granite Surface Plate SIZE 48 X 72 Step 4.2.3.5 correction factor: +0.1 GRADE B TOLERANCE 1400 μ in

CENTER LINE, NORTH TO SOUTH (2) (3) (4) (5) (6) (7) (8) (1) AUTO- ANGULAR SUM OF CUMULATIVE DISPLACE- DISPLACE- DISPLACE- STA. COLL. DISPLACE- DISPLACE- CORRECTION MENT FROM MENT FROM MENT FROM NO. IND. RDGS. MENTS MENTS FACTOR DATUM PLANE BASE PLANE BASE PLANE (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (ARC SEC) (μ INCH) 0 ------+1.1 +1.1 +1.1 +8.0 +155

1 36.6 0 0 +1.0 +1.0 +1.0 +7.9 +153

2 36.4 -0.2 -0.2 +0.9 +0.7 +0.7 +7.6 +147

3 36.3 -0.3 -0.5 +0.8 +0.3 +0.3 +7.2 +140

4 36.5 -0.1 -0.6 +0.7 +0.1 +0.1 +7.0 +136

5 36.6 0 -0.6 +0.6 0 0 +6.9 +134

6 36.9 +0.3 -0.3 +0.5 +0.2 +0.2 +7.1 +138

7 37.5 +0.9 +0.6 +0.4 +1.0 +1.0 +7.9 +153

8 37.4 +0.8 +1.4 +0.3 +1.7 +1.7 +8.6 +167

9 37.1 +0.5 +1.9 +0.2 +2.1 +2.1 +9.0 +175

10 37.0 +0.4 +2.3 +0.1 +2.4 +2.4 +9.3 +180

20 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 1

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.1.3 correction factor: GRADE TOLERANCE

21 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 2

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.1.3 correction factor: GRADE TOLERANCE

22 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 3

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.2.5 correction factor: GRADE TOLERANCE

23 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 4

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.2.5 correction factor: GRADE TOLERANCE

24 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 5

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.2.5 correction factor: GRADE TOLERANCE

25 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 6

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.2.5 correction factor: GRADE TOLERANCE

26 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 7

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.3.5 correction factor: GRADE TOLERANCE

27 NAVAIR 17-20MD-14

CALIBRATION WORKSHEET NO. 8

DATE TEST INST. MFG. OPERATOR SERIAL NO. TEST INST. SIZE Step 4.2.3.5 correction factor: GRADE TOLERANCE

28 NAVAIR 17-20MD-14

CALIBRATION CHECKLIST TEST INST (S) Collins Microflat and Starrett 24 x 36 Surface Plates, Grade A

4.1 Surface Flatness Tests Using an Autocollimator and Mirrors 4.1.3 Worksheet data, NW to SE diagonal line -- ck ( ) NA Data recorded Autocollimator sys repeatability (arc sec) (arc sec) (arc sec) 4.1.4 Station No. 1 -- NA -1.0 to +1.0 4.1.5 Worksheet data, remaining -- ck ( ) NA Data recorded measurement lines

4.2 Surface Flatness Calculations 4.2.1 Diagonal Lines -- ck ( ) NA Data recorded 4.2.2 Perimeter Lines -- ck ( ) NA ” 4.2.3 Center Lines -- ck ( ) NA ” 4.2.4 Line Tie-In Verification (μ in) (μ in) (μ in) 4.2.4.4 Max. diff., tie-in points -- 50 max 4.2.5 Final Calculations Station values (μ in) (μ in) (μ in) 4.2.5.4 Diagonal line, NW-SE -- 200 max ” ” NE-SW -- ” ” North perimeter line -- ” ” East ” -- ” ” South ” -- ” ” West ” -- ” ” Center line, E-W -- ” ” ” N-S -- ”

4.3 Surface Deviation Tests Using a Repeat-O-Meter (μ in) (μ in) (μ in) 4.3.4 Diagonal line, NW-SE -- 70 max

Page 1 of 2

29 NAVAIR 17-20MD-14

CALIBRATION CHECKLIST TEST INST (S) Collins Microflat and Starrett 24 x 36 Surface Plates, Grade A

PROC. NO. NA 17-20MD-14 MFR MODEL SER. NO. PROCEDURE MEASURED VALUES OUT STEP FUNCTION TESTED NOMINAL FIRST RUN SECOND RUN OF CALIBRATION TOLERANCES NO. TOL (1) (2) (3) (4) (5) (6) (7) (μ in) (μ in) (μ in) 4.3.5 Diagonal line, NE-SW -- 70 max ” North perimeter line -- ” ” East ” -- ” ” South ” -- ” ” West ” -- ” ” Center line, E-W -- ” ” ” N-S -- ”

Page 2 of 2

30 NAVAIR 17-20MD-14

CALIBRATION CHECKLIST TEST INST (S) Collins Microflat 48 x 72 Surface Plates, Grade B

4.1 Surface Flatness Tests Using an Autocollimator and Mirrors 4.1.3 Worksheet data, NW to -- ck ( ) NA Data recorded SE diagonal line Autocollimator sys repeatability (arc sec) (arc sec) (arc sec) 4.1.4 Station No. 1 -- NA -1.0 to +1.0 4.1.5 Worksheet data, remaining -- ck ( ) NA Data recorded measurement lines

4.2 Surface Flatness Calculations 4.2.1 Diagonal Lines -- ck ( ) NA Data recorded 4.2.2 Perimeter Lines -- ck ( ) NA ” 4.2.3 Center Lines -- ck ( ) NA ” 4.2.4 Line Tie-In Verification (μ in) (μ in) (μ in) 4.2.4.4 Max. diff., tie-in points -- 100 max 4.2.5 Final Calculations Station values (μ in) (μ in) (μ in) 4.2.5.4 Diagonal line, NW-SE -- 1400 max ” ” NE-SW -- ” ” North perimeter line -- ” ” East ” -- ” ” South ” -- ” ” West -- ” ” Center line, E-W -- ” ” ” N-S -- ”

4.3 Surface Deviation Tests Using a Repeat-O-Meter (μ in) (μ in) (μ in) 4.3.4 Diagonal line, NW-SE -- 160 max

Page 1 of 2

31 NAVAIR 17-20MD-14

CALIBRATION CHECKLIST TEST INST (S) Collins Microflat 48 x 72 Surface Plates, Grade B

PROC. NO. NA 17-20MD-14 MFR MODEL SER. NO. PROCEDURE MEASURED VALUES OUT STEP FUNCTION TESTED NOMINAL FIRST RUN SECOND RUN OF CALIBRATION TOLERANCES NO. TOL (1) (2) (3) (4) (5) (6) (7) (μ in) (μ in) (μ in) 4.3.5 Diagonal line, NE-SW -- 160 max ” North perimeter line -- ” ” East ” -- ” ” South ” -- ” ” West ” -- ” ” Center line, E-W -- ” ” ” N-S -- ”

Page 2 of 2

32 NAVAIR 17-20MD-14

APPENDIX A

REPRESENTATIVE TEST INSTRUMENTS

A.1 TIs which can be calibrated by this procedure include, but are not limited to, the following:

Model/Size Manufacturer Nomenclature Tolerance Limits 24 x 36 Collins Microflat Surface Plate GRADE A 24 x 36 L. S. Starrett ” ” 24 x 48 Collins Microflat ” GRADE B 48 x 60 Herman Stone ” GRADE A 48 x 72 Collins Microflat ” GRADE B 48 x 96 Rock of Ages ” GRADE A

A-1