ASTM D3607 Test Method for Removing Volatile Contaminants from Used Engine Oils
ASTM D3607 Standard Test Method for Removing Volatile Contaminants from Used Engine Oils by Stripping
8. Procedure
8.1 Turn on the heater and thermoregulator of the oil bath and set the bath at 90.0 +/- 0.2°C (Note 1). If a magnetic stirrer is being used, ensure that it is properly positioned beneath the oil bath.
8.2 Weigh the empty 25 by 150-mm glass tube together with the 5-mm glass tubing to be used with it for nitrogen inlet flow. Weigh the assembly to the nearest 0.1 mg.
8.3 Add 25 mL of well-mixed sample to the assembly of 8.2 and reweigh to the nearest 0.1 mg.
8.4 Place the tubes containing oil into the preheated oil bath. The tubes should be positioned so that the entire oil sample is immersed in the bath and between 20 and 40 mm of the tube extends above the bath oil level.
8.5 Before connecting the gas inlet tubing, turn on the nitrogen flow and set it at 400 cm3/min. This flow rate should be maintained to each tube. (Warning - Using pressurized gas is hazardous.)
8.6 Attach the nitrogen delivery flexible tubing to the 5-mm gas inlet tubing in the sample tube and ensure that the inlet tubing is resting just off the bottom of the sample tube.
NOTE 6 - If excessive frothing occurs, decrease the nitrogen flow rate to approximately 50 cm3/min and maintain this lesser rate until frothing subsides before increasing it to 400 cm3/min. Frothing will usually subside within 30 min.
8.7 Maintain the 400-cm3/min nitrogen flow rate after frothing subsides for a total sparging time of 4.5 h.
8.8 Turn off the heater, thermoregulator, stirrer, and nitrogen flow, remove the flexible tubing from the glass inlet tubes, and remove the sample tubes (still containing the glass inlet tubes) from the oil bath.
8.9 Wipe the outside of the sample tube completely dry, allow the assembly to cool to room temperature, and reweigh to the nearest 0.1 mg. The oil sample in the tube is now free of diluent.
NOTE 7 - If the kinematic viscosity of the stripped sample is desired, the sample should be reheated to about 60°C and filtered while still warm before undertaking the kinematic viscosity measurement. This is especially important if the used oil contains solid particles. See Test Method D445 for determining the kinematic viscosity and filtering of the oil.
9. Calculation
9.1 Calculate the volatile contaminants content of the sample as weight percent volatile contaminants as follows:
Volatile contaminants, mass % = [(A - B)/A] x 100
where:
A = weight of original sample, g, and
B = weight of sample after stripping, g.
