1、 FORD LABORATORY TEST METHOD EU AJ 051-01 Date Action Revisions 2000 08 07 Editorial no technical change A. Cockman 2000 03 10 Editorial no technical change A. Cockman 1993 10 18 Printed copies are uncontrolled Page 1 of 6 Copyright 2000, Ford Global Technologies, Inc. METHOD OF CARBON TYPE ANALYSIS
2、 OF LUBRICATING OILS BY INFRARED SPECTROSCOPY Scope This method is primarily applicable to additive - free lubricating oil base - stocks. A carbon - type analysis is obtained in terms of % C, % C N and % Cp, being the percentages of the total number of carbon atoms in aromatic, napthenic, and paraff
3、inic structures respectively. This method is limited to the ranges: C A 3 % - 25 % Cp 43 % - 72 % This method may also be utilized with additive containing oils providing it is recognized that the figures obtained will be modified by the type and quantity of additive present. Apparatus Required 1. D
4、ouble beam recording infrared spectrometer or equivalent capable of recording over the wavenumber range 4000 - 600 cm - 1. 2. A sa mple cell fitted with sodium chloride or potassium bromide windows. This can be a cell of either fixed or variable path length. In either case, the path - length should
5、lie in the range 0.09 to 0.12 mm and be known accurately to within 0.002 mm. 3. Syringe . 4. Lens Tissue. Materials Required 1. Two calibration oils having the following approximate values of C A and Cp Oil 1 C A = 5.9 % Cp = 67.0 % Oil 2 C A = 21.5 % Cp = 44.0 % FORD LABORATORY TEST METHOD EU AJ 05
6、1-01 Page 2 of 6 Copyright 2000, Ford Global Technologies, Inc. Actual values will be declared on the calibration oils as suppli ed. Source: Materials Laboratory 13/100 Ford - Werke A.G. NU/FIL Ford Motor Company Limited Central Laboratory Laindon, Basildon, Essex 5 K8ln - Niehl 2. Chloroform (A.R.)
7、 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 conditions unless otherwise specified. Procedure A. Cell
8、Calibration The cell pa th length is determined by the interference fringe method. 1. Place the empty cell in the spectrometer and select the wavenumber region to be scanned such that the maximum number of interference fringes can be counted. 2. Mark the middle of two troughs o n the spectrum and co
9、unt the number of interference fringes between these two points. Note the wavenumbers coincident with these points. The cell path length is calculated as follows: Cell Path Length (mm) = N x 10 2 (L 1 - L 2 ) Where N - Number of i nterference fringes between L 1 and L 2 . L 1 and L 2 = Wavenumbers b
10、etween which fringes are counted. Note: Cell Cleaning 1. After use the cell should be cleaned immediately. 2. Flush cell with approximately 20 mL chloroform 3. Evaporate chloroform with a st ream of warm dry air, to avoid condensation of water on cell windows. 4. If warm air is not available, the ce
11、ll may be mounted in the instrument beam so that the cell can be warmed by the infra - red radiation. FORD LABORATORY TEST METHOD EU AJ 051-01 Page 3 of 6 Copyright 2000, Ford Global Technologies, Inc. B. Calibration Fill the cell with No. 1 calib ration fluid. Ensure that no bubbles are trapped bet
12、ween the windows, and place in the sample beam of the spectrometer. Adjust the 100% control so that the pen lies between 90% and 95% transmission at 2000 cm - 1. Record the spectrum from 4000 600 cm - 1. Empty and clean the cell. Fill with No. 2 calibration fluid and record spectrum as before. Measu
13、re the transmittance at the peak maxima of the absorption bands which occur between the following wavenumbers. 1. 1615 - 1585 cm - 1 (for measurement of % C A ) 2. 820 - 800 cm - 1 (for measurement of % C A ) 3. 730 - 715 cm - 1 (for measurement of % Cp) The transmittance measurement for each band i
14、s undertaken, as per figures 1 and 2, by drawing tangential base lines between the peak minima as follows: For the 1615 - 1585 cm - 1 absorption band, draw the base line between approximately 1640 and 1540 cm - 1. For the 820 - 800 cm - 1 absorption band, draw the base line between approx 835 and 78
15、5 cm - 1. For the 730 - 715 cm - 1 absorption band, draw the base line between appro x. 790 and 685 cm - 1. An absorption X is then converted to absorption per mm, K; thus: K = Log Io/I d Where K = absorbance per mm I = minimum transmittance (%) Io = maximum transmittance (%) d = cell path length (m
16、m) For each oil calculate the quant ities: Q A = 1.86 K 1 + K 2 and Qp = K 3 - 1.63 K 1 (Note: Qp can be a negative value). Where K 1 ; K 2 ; K 3 are the respective K values for the absorption bands quoted in 1, 2 and 3 above. To calibrate for % C A and % C p , plot the Q A and Q p values against th
17、e corresponding C A and C p values respectively. Join the points by straight lines. FORD LABORATORY TEST METHOD EU AJ 051-01 Page 4 of 6 Copyright 2000, Ford Global Technologies, Inc. (c) 1. Measurement of Sample: (Non - Additive Oils) Record the spectrum of the oil sample as above. Calculate Q A an
18、d Q p ; read off from the calibration lines the correspondin g values of C A and C p . C N is calculated from: C N = 100 - (C A + C p ) 2. Measurement of Sample: (Additive Containing Oils) Record the spectrum of the oil sample as above. Where an absorption band occurs between 2000 - 1615 cm - 1 adja
19、cent to and having an i nfluence on the aromatic band to be measured, the base - line drawn between 1640 and 1540 cm -1 should be extended to 2000 cm - 1. If this base - line intersects the spectrum trace of any absorption bands in the 2000 1615 cm - 1 region, a new tangential base lin e should be d
20、rawn between 1850 and 1540 cm - 1 approx. and the absorption for the aromatic band at 1615 - 1585 cm - 1 measured from this line as shown in Figure 3. Note: If the absorption band of the additive content does not influence the aromatic absorptio n band, then evaluation of the spectrum is carried out
21、 as detailed in (c) 1. Calculate Q A and Q p ; read off from the calibration lines the corresponding values of C A and Cp. C N is calculated from: C N - 100 - (C A + Cp) Reporting Report C A to the nearest 0.1 unit, and Cp and C N to the nearest whole number. Chemicals, materials, parts, and equipme
22、nt referenced in this document must be used and handled properly. Each party is responsible for determining proper use and handling in its facilities. FORD LABORATORY TEST METHOD EU AJ 051-01 Page 5 of 6 Copyright 2000, Ford Global Technologies, Inc. METHOD OF CARBON TYPE ANALYSIS F LUBRICATING OILS BY INFRARED SPECTROSCOPY Figure 1 SECONDARY STANDARD (1) Figure 2 SECONDARY STANDARD (1) FORD LABORATORY TEST METHOD EU AJ 051-01 Page 6 of 6 Copyright 2000, Ford Global Technologies, Inc. METHOD OF CARBON TYPE ANALYSIS OF LUBRICATING OILS BY INFRARED SPECTROSCOPY Figure 3
