ASTM D6335 Determination of High Temperature Deposits by Thermo-Oxidation Engine Oil Simulation Test
7. Calibration
7.1 The TEOST instrument is calibrated by performing the procedure found in Section 8-16 for both a low and a high deposit reference oil. The results shall be within the repeatability limits established by the supplier of the reference oils.
7.2 The calibration should be performed a minimum of every three months, as recommended by the instrument manufacturer.
7.3 If the repeatability is not within the established limits, the instrument setup steps in Section 8 should be performed. Then the reference oil should be rerun.
8. Setup of the Test Instrument
8.1 Pump Speed Calibration - The pump speed should be calibrated using the instructions found in Annex A1. It is recommended that this calibration be done every three months.
8.2 Thermocouple Depth - The thermocouple depth setting (distance from tip to locking collar) should be determined using the procedure in Annex A2. The depth setting should be checked daily and should be redetermined whenever a new thermocouple is installed.
8.3 Power Adjustments - The procedure for making power adjustments is given in Annex A3. It is recommended that the power adjustments be made by a qualified instrument technician.
8.4 Verify that the temperature program shown in Table 1 is entered. When verifying the temperature program, always press RETURN when assured soak is displayed.
9. Assembly of Apparatus
9.1 Assemble the TEOST system by placing the reaction chamber in the bolt seats on the TEOST platform with the drain and gas inlet tubing facing the right side of the instrument.
9.2 Connect the pump inlet tube to the outlet connection of the reaction chamber and the inlet connection of the pump. Finger tighten the connections.
9.3 Connect the pump outlet tube to the outlet connection of the pump, and place a 10 mL graduated cylinder directly under the open end of the pump outlet tube.
9.4 Place the lid containing the thermocouple on the reaction chamber, making sure that the thermocouple is touching the bottom of the reaction chamber.
9.5 Wrap the heating jacket around the reaction chamber and secure it with the provided straps. Connect the heating jacket and the thermocouple to the labeled connections on the back wall of the instrument. The connectors shall be inserted and twisted to obtain a proper connection. Use the reactor temperature controller to set the temperature of the reaction chamber to 100°C.
9.6 Connect the gas tubing to the reaction chamber, and set the flow meters for the moist air and N2O to 3.5 mL/min. These are allowed to flow to purge out the lines before the test begins.
NOTE 2 - Be sure the valve on the reaction chamber is pointing up to allow the gases to enter into the chamber.
10. Sample Preparation
10.1 After thoroughly mixing the test sample, use a graduated cylinder to measure 116 mL of the fluid and pour it into a 600-mL beaker. Use a syringe to add 193 µL of the 6 % ferric napthenate solution to the 116 mL of test fluid. The resulting concentration of iron in the test fluid will be about 100 wt ppm.
10.2 Use a magnetic bar and stirrer to mix the oil and ferric naphthenate thoroughly for 5 min.
