ASTM D7042 Test Method for Dynamic Viscosity and Density of Liquids by Stabinger Viscometer (and the Calculation of Kinematic Viscosity)
11. Procedure
11.1 Standard procedure (rinsing and drying)
11.1.1 Set the internal temperature control to the desired measuring temperature.

11.1.2 Set the determinability limits and temperature stability criteria to the values stated in Table 1 for the specific product.

11.1.3 Make sure that the measuring cells are clean and dry as described in 12.1.

11.1.4 Load a minimum of 3 mL of the test specimen to the syringe if enough sample is available it is recommended to fill the entire syringe. Pour at least 2 mL of the test specimen into the measuring cells. Leave the syringe in the inlet opening and start the measurement. Wait for the instrument to indicate that the determination is valid and record the values.

11.1.5 Inject a further 1 mL without taking off the syringe and repeat the measurement.

11.1.6 If the deviation between two consecutive determinations exceeds the determinability limits as stated in Table 1 for this product, repeat step 11.1.5 until the deviation is within these limits. Discard all previously determined values and report the values of the last determination as the result.
11.1.6.1 For products not listed in the precision section, it is the responsibility of the user of this standard to establish reasonable determinability limits by a series of tests.

11.1.6.2 If the syringe is empty before obtaining a valid determination, rinse and dry the measuring cells as described in 12.1 and repeat step 11.1.4. Ifit is not possible to obtain a valid result within an applicable number of repetitions, report the robust mean value and the standard deviation (k = 2; 95 % confidence level) together with a remark indicating that the determinability exceeded the limits stated in 15.2.1 for this product.

11.1.7 Remove the test specimen immediately, rinse and dry the measuring cells as described in 12.1.

11.2 Alternative Procedure (Sample Displacement) - For a series of samples that are mutually soluble (for example, various diesel fuels). It is the responsibility of the user of this standard to determine the applicability of this procedure to each class of samples.
11.2.1 Set the internal temperature control to the desired measuring temperature.

11.2.2 Set the determinability limits and temperature stability criteria to the values stated in Table 1 for the specific product.

11.2.3 Make sure that the measuring cells are clean and dry as described in 12.1.

11.2.4 Load a minimum of 5 mL of the test specimen to the syringe if enough sample is available it is recommended to use a 10 mL or larger syringe and to fill the entire syringe. Pour slowly at least 3 mL of the test specimen into the measuring cells. A slow flow ensures that the new test specimen displaces the old one rather than merging with it. Leave the syringe in the inlet opening and start the measurement. Wait for the instrument to indicate that the determination is valid and record the values.

11.2.5 Inject slowly a further 2 mL without taking off the syringe and repeat the measurement.

11.2.6 If the deviation between two consecutive determinations exceeds the determinability limits as stated in Table 1 for this product, repeat step 11.2.5 until the deviation is within these limits. Discard all previously determined values and report the values of the last determination as the result.
11.2.6.1 For products not listed in the precision section it is the responsibility of the user of this standard to establish reasonable determinability limits by a series of tests.

11.2.6.2 If the syringe is empty before obtaining a valid determination repeat step 11.2.4. If it is not possible to obtain a valid result within an applicable number of repetitions, report the robust mean value and the standard deviation (k = 2; 95 % confidence level) together with a remark indicating that the determinability exceeded the limits stated in 15.1.1 for this product.

11.2.7 For the next sample of this series repeat the steps 11.2.4-11.2.6.

11.2.8 After the last sample of a series perform a cleaning procedure as described in 12.1.

11.3 Procedure for Use with Autosampler:
11.3.1 Set the determinability and temperature stability criteria to values in Table 1 for the corresponding testing parameter(s) and temperature(s) of interest. Temperature control/stability requirements at the test temperatures of interest are provided in 6.1.3. For all other sample types, see 11.3.2 for guidance.

11.3.2 For products not listed in the precision section, it is the responsibility of the user of this test method to establish reasonable determinability and temperature stability criteria by a series of tests.

11.3.3 Configure the cleaning and drying routines for the autosampler for sufficient cleaning efficiency of the product being tested.

NOTE 3 - For specific information on proper configuration, follow the manufacturer's instructions.

11.3.4 Configure the autosampler for a minimum of two consecutive determinations per sample.

11.3.5 Transfer a portion of the sample into the appropriate sample vial. Cap or cover the vials as necessary.
11.3.5.1 Load sample(s) vial onto vial tray or holder and analyze the test specimens.

11.3.5.2 Evaluate the data. Rerun samples which exceed the determinability criteria established for the sample type being analyzed. (See 11.3.1 and 11.3.2.)

12. Cleaning of the Measuring Cells
12.1 Fill the measuring cells with at least 3 mL of the sample solvent (see 7.1). Check if the density cell is filled completely by examining the displayed density value. Start the motor for at least 10 s. For poorly soluble samples, extend this time and repeat the procedure. Then rinse the measuring cells with the drying solvent (see 7.2) and pass through a stream of dry air or nitrogen until the last trace of solvent is removed. Make sure that the measuring cells are clean and dry by checking if the air density value is lower than 0.0020 g/cm3. If the value exceeds this limit repeat the procedure or parts of it.

12.2 Special Cleaning Procedure - If necessary, clean the viscosity measuring cell by manually wiping and brushing the measuring rotors using a suitable sample solvent. If necessary clean the density oscillator using suitable cleaning agents. This procedure must be carried out when repeated calibration check measurements do not agree with the acceptable tolerance as stated in 9.4. Follow the instructions of the manufacturer of the apparatus.

13. Calculation of Results
13.1 The recorded values are the final results, expressed either as dynamic viscosity in millipascal-seconds or as kinematic viscosity in square millimetre per second and as density in grams per cubic centimetre or kilograms per cubic metre.

13.2 Viscosity Index - If results are available from the same sample at 40 °C and at 100 °C the Viscosity Index (VI) can be calculated according to Test Method D2270 from the kinematic viscosity results at the above temperatures.

13.3 Density Extrapolation - If results are available from the same sample at 40 °C and at 100 °C density values at other temperatures can be calculated by linear extrapolation from the density results at the above temperatures. The limit for this extrapolation temperature is given by the point where changes of state (for example, cloud point or gassing) of the involved sample occur. It is the responsibility of the user of this standard to determine the applicability of this calculation to each class of samples.