1、 FORD LABORATORY TEST METHOD BI 019-01 Date Action Revisions 2001 03 13 Revised Editorial no technical change A. Cockman 1992 06 19 Printed copies are uncontrolled Page 1 of 8 Copyright 2001, Ford Global Technologies, Inc. TEST PROCEDURES FOR THICKNESS MEASUREMENT OF CLEAR SYNTHETIC BAKING ENAMEL CO
2、ATING ON SYNTHETIC WOOD Application The following procedures describe the use of the Zeiss light section microscope for the nondestructive thickness measurement of clear synthetic baking enamel coatings on synthetic wood exterior trim for station wagons. This light section microscope has been specia
3、lly designed for testing and measuring the surface quality of production parts. The operating procedures in the instrument manual are limited to this application only. However, this instrument, having its design based upon the light section principle, has been found to be adaptable to the measuremen
4、t of thin film thicknesses of any transparent coating over both magnetic and nonmagnetic surfaces. (Reference: Special Report MDJA 8112.4-5 “A Nondestructive Method for Measuring the Thickness of Thin Transparent Coatings over Metallic and Nonmetallic Surfaces“, by T.M. Mansour, Process Development
5、Dept., Manufacturing Engineering & Development Office, Manufacturing Staff, March 1962 - Job Nos. 1-H-64 and 2-A-38. Apparatus Required Zeiss Light Section Microscope The basic light section microscope unit, shown in attached photograph, consists of the following major components: 1. A microscope wi
6、th built-in illumination device, built-in measuring eyepiece, and two pairs of objectives for 200X and 400X total magnifications respectively. 2. A stand with stage plate. 3. Three 6-volt, 5-watt incandescent lamps in centering mounts (two as spares). 4. A power supply unit for 110 volt, 60 cycle op
7、eration. 5. A dust protection sheath. COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 2 of 8 Copyright 2001, Ford Global Technologies, Inc. 6. Instrument manual Note: This light section microscope is manufactured by: Carl Zeiss, Inc. 48
8、5 Fifth Avenue New York 17, New York The local distributor is: Harshaw Scientific Co. 9240 Hubbell Avenue Detroit, Michigan The ordering code number for the above mentioned basic equipment is 60/49/99. 7. A mechanical stage with V-bearings is available as a supplementary accessory (Code No. 60/49/96
9、). This was found to be quite helpful in positioning relatively small test samples. Flat Glass Reference Surface A flat glass reference surface is required for proper alignment of the slit image. This is recommended to be an approximately 2 x 2 inch piece of plate glass, of 1/32 inch minimum thickne
10、ss. Sample Holder The sample holder is recommended to be a clamping device (or equivalent), compatible with the size and shape of the samples to be tested, which will facilitate positioning the test sample so that the test area is very nearly normal to the axis of the microscope. The test area is ap
11、proximately 1/16 inch long and of negligible width. Conditioning and Test Conditions All test values indicated herein are based on material conditioned in a controlled atmosphere of 23 +/- 2 C and 50 +/- 5 % relative humidity for not less than 24 h prior to testing and tested under the same conditio
12、ns unless otherwise specified. COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 3 of 8 Copyright 2001, Ford Global Technologies, Inc. Procedure A. Instrument Set-Up 1. Place the instrument on a flat and relatively vibration-free surface.
13、 2. Insert the instrument cable into the plug of the power supply unit and connect the latter to a 110 volt, 60 cycle power line. 3. Switch the power supply unit on by setting the knob provided to any mark between 1 and 8 on the graduated disc. This setting may later be changed to obtain a desired l
14、evel of illumination. B. Initial Focus and Alignment 1. Focus the cross lines, visible through the eyepiece, as outlined in the instrument manual (supplied by the manufacturer). 2. Place the flat glass reference surface on the stage plate. The surfaces of this glass piece must be thoroughly clean -
15、free of fingerprints, grease film, etc. 3. Looking into the eyepiece, lower the microscope body by turning the vertical drive knob slowly, to obtain a well-focused light band. 4. This light band should be parallel to the horizontal portion of the cross-lines. If it is not parallel, it should be alig
16、ned accordingly by means of the knob provided, as outlined in the instrument manual. Once this light band has been properly aligned, the aligning knob should not be touched in the course of instrument operation. 5. By means of the vertical drive knob, elevate the microscope body to a safe clearing d
17、istance between objectives and stage plate. 6. Remove the glass reference surface from the stage plate. C. Selecting the Objectives 1. For measuring coating thicknesses greater than 0.4 mils, use the 200X total magnification pair of objectives. (Refer to the discussion under this heading in the inst
18、rument manual). When using this level of magnification, each division on the micrometer measuring drum is equivalent to 1 micron. The 400X magnification objectives are used in measurement of thicknesses less than 0.4 mils. At this level of magnification, each division on the measuring drum is equiva
19、lent to 1/2 micron. COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 4 of 8 Copyright 2001, Ford Global Technologies, Inc. D. Coating Thickness Measurement 1. Place the test sample directly below the microscope objectives. A relatively s
20、mall sample may be placed on the stage plate. For measurements on larger samples, the microscope body can be swiveled through 180. 2. Looking into the eyepiece, turn the focusing drive knob slowly, advancing the microscope toward the test area, until a focused two-lined image of the light band appea
21、rs in the field of view. Adjust the power supply unit knob to obtain the desired level of illumination. Note: This two-lined image will consist of two essentially parallel bands: A lower band adopting the profile of the top surface of the coating and an upper band adopting the surface profile of the
22、 coated surface. 3. In the case of a flat test surface, the light bands should be essentially parallel to the horizontal cross-line, if the test area is properly positioned (normal to the axis of the microscope). See Figure 1. If these are not parallel, the test sample position should be altered acc
23、ordingly. Use the flat or straight line in conjunction with the horizontal cross-line for this alignment. Care must be taken when adjusting the sample position to avoid bumping the microscope objectives. 4. In the case of a curved test surface, these light bands will, of course, appear curved accord
24、ingly. Here the test area needs to be positioned so that the center of curvature lies on the axis of the microscope (or an extension of it, depending on whether this curvature is concave or convex). This position is easily achieved by adjusting the sample position until a well-defined image similar
25、to that in Figure 2 (or an inverted image of it, depending on the type of curvature) is visible in the field of view. 5. Disregarding the vertical portion of the cross-lines visible in the eyepiece, set the horizontal portion at the lowest “valley(s)“ of the upper band and record the measuring drum
26、setting. See first position of horizontal cross-line in Figures 1 and 2. 6. Turn the micrometer measuring drum to move the horizontal cross-line to the center of the lower band (second position of horizontal cross-line Figures 1 and 2), and record this measuring drum setting. 7. Subtract the first r
27、eading from the second to obtain the instrument reading in microns. 8. Refer to the attached conversion chart to obtain the coating thickness in mils from the micron reading for clear synthetic baking enamel (M 14533). For this material, the conversion factor necessary is (microns x 0.076), (Referen
28、ce: Special Report MDJA 8112.4-5, referred to in the introduction section of this test procedure). COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 5 of 8 Copyright 2001, Ford Global Technologies, Inc. Routine Care and Maintenance 1. Kee
29、p all exposed parts of the instrument clean and covered with the supplied protective sheath when not in use. 2. Avoid sudden jarring or bumping of the instrument. 3. To prolong the life of the illumination lamp, do not set the power supply unit higher than the #8 mark on the graduated disc, and turn
30、 off when not in use. Refer to the instrument manual for lamp replacement. 4. The instrument can, in some cases, be operated with room overhead lights on, however, the distinctness of image will be appreciably enhanced when viewed in a dark surrounding. Chemicals, materials, parts, and equipment ref
31、erenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 6 of 8 Copyright 2001, Ford Global Technolo
32、gies, Inc. TEST PROCEDURES FOR THICKNESS MEASUREMENT OF CLEAR SYNTHETIC BAKING ENAMEL COATING ON SYNTHETIC WOOD COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 7 of 8 Copyright 2001, Ford Global Technologies, Inc. TEST PROCEDURES FOR TH
33、ICKNESS MEASUREMENT OF CLEAR SYNTHETIC BAKING ENAMEL COATING ON SYNTHETIC WOOD Figure 1 Figure 2 COPYRIGHT Ford Motor CompanyLicensed by Information Handling ServicesFORD LABORATORY TEST METHOD BI 019-01 Page 8 of 8 Copyright 2001, Ford Global Technologies, Inc. TEST PROCEDURES FOR THICKNESS MEASUREMENT OF CLEAR SYNTHETIC BAKING ENAMEL COATING ON SYNTHETIC WOOD COPYRIGHT Ford Motor CompanyLicensed by Information Handling Services
