ASTM D7214 Standard Test Method for Determination of the Oxidation of Used Lubricants by FT-IR Using Peak Area Increase Calculation
7. Apparatus
7.1 FT-IR Spectrophotometer, suitable for recording measurements between 1650 cm(-1) and 1820 cm(-1) and with a resolution of 4 cm(-1).

7.2 Transmission Cell, with windows of potassium bromide, having a known pathlength of approximately 0.025 to 0.1 mm.

7.3 Syringe, or Other Automated or Semi-Automated Device, with adequate volume to fill the cell, for example, 2 mL.

8. Reagents and Materials
8.1 Purity of Reagents - Reagent grade chemicals shall be used in all tests. Unless otherwise indicated, it is intended that all reagents shall conform to the specifications of the committee on Analytical Reagents of the American Chemical Society, where such specifications are available. Other grades may be used, provided it is first ascertained that the reagent is of sufficiently high purity to permit its use without lessening the accuracy of the determination.

8.2 Heptane, used as cleaning solvent. Other solvents and solvent mixtures may be used provided they adequately clean the cell(s) between samples. A 50/50 mixture of cyclohexane and toluene has been found to be useful in cleaning cells after highly contaminated and degraded samples have been run. (Warning - Flammable.)

8.3 PAO4, used as dilution oil (PAO4: PolyAlphaOlefin with a kinematic viscosity at 100°C of approximately 4 mm2/s)