ASTM D6278 Standard Test Method for Shear Stability of Polymer Containing Fluids Using a European Diesel Injector Apparatus
11. Procedure
11.1 Flow Rate Adjustment for Test Oil - Open the stopcock on the atomization chamber and drain any previous fluid out of the chamber. Position the three-way stopcock ((6) in Fig. A1.1) below the cooling jacket to discharge fluid into a suitable waste container. Then, position stopcock (8) so that the drain line is closed but line (10) is open from the fluid reservoir to the pump.
11.1.1 Add a minimum of 50 mL of test fluid to the fluid reservoir.

11.1.2 Free the apparatus of air in the line by manual compression of the flexible tube that connects the pump to the fluid reservoir. When necessary, the venting screw (14) is also used for this purpose.

11.1.3 Operate the pump until the fluid reservoir is empty, but line (10) is full.

11.1.4 Add a minimum of 50 mL of test fluid to the fluid reservoir a second time and operate the pump until the fluid reservoir is empty again but line (10) is still full.

11.1.5 After draining is complete, close the stopcock on the atomization chamber and position stopcock (6) so that fluid will flow from the cooling jacket into the fluid reservoir.

11.1.6 Add an amount of test fluid to the fluid reservoir equal to the sum of 30 mL plus Vrun.

11.1.7 Free the apparatus of air in the line by use of the venting screw (14) and by manual compression of the flexible tube that connects the pump to the fluid reservoir.

11.1.8 Set the stroke counter to the product of three times n. The pump shall run for 3 min. Obtain a timing device to observe the time the stroke counter is on to ensure n is correct. Start the pump and allow oil to circulate until the impulse counter shuts down the instrument.

11.1.9 Adjust the oil level in the fluid reservoir to Vrun by draining any excess oil to a waste container, or adding oil when needed.

11.1.10 Set the impulse counter to the product of 0.5 times n.

11.1.11 Close stopcock (6) so that fluid will be stored in the cooling jacket after the pump is started.

11.1.12 Start the pump. When the pump stops, subtract the volume now in the fluid reservoir (7) from Vrun.

11.1.13 When the difference is within +/- 2.5 mL of half of Vtot, proceed to 11.2.

11.1.14 If the volume in the fluid reservoir is not within +/- 2.5 mL of Vtot, adjust the pump stroke slightly by means of the pump adjustment screw (12) drain the fluid from the cooling jacket into the fluid reservoir, and repeat steps beginning with 11.1.6.

11.2 Removal ofFluid - Leave stopcock below atomization chamber closed. Drain the fluid from the cooling jacket into a waste container then re-position the stopcock so that the fluid will flow into the fluid reservoir. Then open the three-way stopcock below the fluid reservoir to discharge fluid into a waste container.
11.2.1 Test Oil Evaluation - Re-position stopcock (8) so that line (10) is open. Leave the stopcock below the atomization chamber closed. Re-position stopcock (6) below the cooling jacket so that the first 50 mL of test oil is sent to a waste container.

11.2.2 Place a volume of test oil in the fluid reservoir equal to Vrun plus 30 mL.

11.2.3 Free the apparatus of air in the line by manual compression of the flexible tube that connects the pump to the fluid reservoir. When necessary, the venting screw (14) is also used for this purpose.

11.2.4 Start the pump, and stop the pump when there is a 50 mL drop of fluid in the fluid reservoir. When draining is complete, re-position the stopcock below the cooling jacket so subsequent fluid flows directly into the fluid reservoir.

11.2.5 Set the stroke counter for automatic shutoff at the required number of impulses (30 multiplied by n impulses per minute).

11.2.6 When necessary, adjust the volume in the fluid reservoir to Vrun.

11.2.7 Insert the thermometer assembly or temperature probe in the fluid reservoir.

11.2.8 Start the pump.

11.2.9 Within the first 10 min, adjust the water flow to control the fluid temperature at 30 °C to 35 °C, as measured at the discharge point of the fluid reservoir.

NOTE 18 - It is not necessary to record the gauge pressure reading here, which may differ from the previously recorded calibration pressure.

11.2.10 After 30 cycles has elapsed and the pump had stopped, open the stopcock below the atomization chamber and drain fluid into a waste container. Open the three-way stopcock below the fluid reservoir and discharge the first 10 mL to 15 mL as waste in order to flush out the drain line. Discharge the remaining fluid into a clean sample container. Remove the thermometer assembly or probe.

11.2.11 Using Test Method D445, determine the kinematic viscosity at 100 °C of unsheared (untested) test fluid, as well as the sheared fluid from 11.2.10. Use the same viscometer tube for the measurement of each oil.

12. Calculation
12.1 Calculate the percent viscosity loss (PVL) of the sheared oil as follows:
PVL = 100 x (Vu - Vs)/Vu
where:
Vu = kinematic viscosity of unsheared oil at 100 °C, mm2/s, and
Vs = kinematic viscosity of sheared oil at 100 °C, mm2/s.