ASTM D7261 Standard Test Method for Determining Water Separation Characteristics of Diesel Fuels by Portable Separometer
10. Preparation of Apparatus
10.1 Locate the instrument on a clean workbench in an area where the temperature is between 18 °C and 29 °C and does not vary more than +/- 3 °C.
10.2 Open the case, and raise the right panel until completely vertical and locked in place.
10.2.1 If ac power is available, connect the power cord.
NOTE 6 - The Micro-Separometer can be purchased with or without an internal battery pack.
10.2.2 If the internal battery power is used, ensure that the batteries are charged sufficiently to perform the desired number of tests.
NOTE 7 - Low battery power on the Mark V Deluxe instrument is indicated when the power lamp does not illuminate. The Mark X will display an ERR-06 indicating a LO BAT condition, indicating that the battery is not sufficiently charged to run a test. To recharge the battery, connect the instrument to an ac power source for at least 16 h (full charge) prior to use. Approximately 25 tests can then be performed.
10.2.3 Turn the Mark V Deluxe and Mark X instruments on by depressing the switch (push button) marked ON.
NOTE 8 - The on-power indicator light will alternately pulse on and off when the instrument is connected to an ac power source and will stay on continuously when operated by the battery pack (dc power source). Flickering of the power indicator light, during any portion of a test sequence being performed using battery power, indicates that recharging is necessary.
10.3 Have ready a supply of syringes, syringe plugs, vials, DCell or DBCell coalescers, the pipet and pipet tips, and a clean container of double-distilled water.
NOTE 9 - Syringe drive travel times during the coalescing test period were initially calibrated at the factory for each mode of operation and have a significant bearing on the final test results. Syringe drive travel times exceeding the upper limit will cause the final results to measure high; conversely, travel times below the lower limit will cause the final results to measure low. Mark V Deluxe and Mark X instruments have self-check circuitry to detect out-of-tolerance syringe drive travel times. The Mark V Deluxe alert indicator lamp (marked SYR) illuminates and depending on the degree (more than 3 s) of the out-of-tolerance condition, three short (1-s) tones will also sound. The Mark X ERROR ALERT indicator illuminates and ERR-03 is displayed. An occasional out-of-tolerance alert may be experienced due to some intermittent condition, which probably will not be indicative of instrument failure. However, repeated alerts are cause for returning the instrument to the factory for adjustment.
11. Sampling and Sample Preparation
11.1 Rinse the sample container three times with the product to be sampled before collecting the sample. Collect a sample of at least 1 L, and preferably about 3 L, in a clean container in accordance with Practice D4057 or D4177.
NOTE 10 - Test method results are known to be sensitive to trace contamination from sampling containers. For recommended sampling containers, refer to Practice D4306. Special precautions concerning sample containers and sampling technique are discussed in Appendix X1. Extreme care and cleanliness are required in taking samples either directly into the test syringe or into a sample container.
11.1.1 Before pouring the test sample from the container, wipe the container outlet thoroughly with a clean, lintless wiper; pour the test sample into a clean beaker or directly into the barrel of the test syringe.
11.2 (Warning - Do not, under any circumstances, prefilter the test fuel. The filter media can remove the very materials, surfactants, that the test method is designed to detect. If the test fuel is contaminated with particulate matter, allow such materials to settle out of the fuel before testing. Test methods such as D4176, D4860, and D6426 may be used to determine the quality and cleanliness of the sample.)
NOTE 11 - If a sample does not clear up after being allowed to stand for a period of time, the sample cannot be tested by this test method (6.1).
11.3 Ifthe sample is not within the test temperature limits of 18 °C to 29 °C, allow the sample to stand or place the sample container in a water bath until the temperature is within the prescribed limits. The preferred temperature for testing is approximately 23 °C.
12. Calibration and Verification
12.1 The instrument is calibrated at the factory by using inhouse test equipment.
12.2 Instrument performance, especially for field use, may be verified by performing DSEP tests using a dilution of the dispersing agent (as prepared in 8.3), a reference fluid base (as prepared in Annex A1), and double-distilled water.
12.2.1 Prepare a 10:1 dilution by diluting 10 mL of dispersing agent (8.2) with 90 mL of toluene.
NOTE 12 - Since 1 mL of dilution is equal to 0.1 mL of dispersing agent, 50 µL of dilution is equal to 0.1 mL/L when added to 50 mL of reference fluid base. The 0.1 mL/L of dispersing agent corresponds to even multiples of the concentration levels listed in Table 2.
12.2.2 Use the 50 µL pipet (8.3.5) to add increments of 0.1 mL/L of dispersing agent to reference fluid base.
12.2.3 Perform DSEP tests with several reference fluids and double-distilled water (8.7) according to Section 13.
12.2.4 Compare the DSEP ratings to the values listed in Table 2 for the particular concentration of dispersing agent used.
12.3 If the results do not fall within the range of limits shown in Table 2, the reference fluid shall be discarded and a fresh quantity of reference fluid prepared and the verification repeated.
12.4 If repeated verification tests give out-of-tolerance test results, return the instrument to the factory for adjustment and recalibration.
