ASTM D3948 Determining Water Separation Characteristics of Aviation Turbine Fuels
ASTM D3948 Standard Test Method for Determining Water Separation Characteristics of Aviation Turbine Fuels by Portable Separometer
8. Preparation of Apparatus
8.1 Locate the instrument on a clean workbench in an area where the temperature is between 18 and 29°C (65 and 85°F) and does not vary more than ±3°C (5°F).
8.2 Open the case and remove the six-pack box from the lid. Raise the right panel until completely vertical and locked in place. If a-c power is available, connect the power cord and turn the instrument on. If the internal battery power is used, assure that the batteries are charged sufficiently to perform the desired number of tests. Low battery power is indicated when the power lamp does not illuminate. Connect the instrument to an a-c power source for at least 16 h (full charge) prior to use. Approximately 25 tests can then be performed.
8.2.1 Mark V Deluxe instruments are turned on by depressing the switch (pushbutton) marked ON. The ON power indicator light will alternately pulse on and off when the instrument is connected to an a-c power source and will stay on continuously when operated by the battery pack. Flickering of the power indicator light, during any portion of a test sequence being performed using battery power, indicates that recharging is necessary.
8.3 Have ready a supply of syringes, vials, Alumicel coalescers, syringe plugs, and pipet tips, as well as a clean container with distilled water. All of the items except the container and water are furnished in the six-pack provided with the instrument. In addition, have the wire aid and pipet readily available.
8.4 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.
NOTE 3 - 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.
8.4.1 Mark V Deluxe instruments have self-check circuitry to detect out of tolerance syringe drive travel times. The 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. 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.
9. Sample Preparation
9.1 Under no circumstances shall test fuel be prefiltered as 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.
9.2 Special precautions concerning sample containers and sampling technique are discussed in Appendix X2. Extreme care and cleanliness are required in taking samples either directly into the test syringe or into a sample container. 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.
NOTE 4 - Test method results are known to be sensitive to trace contamination from sampling containers. For recommended sampling containers refer to Practice D4306.
9.3 If the sample for test is not within the test temperature limits, 18° to 29°C (65° to 85°F), allow the sample to stand until an in tolerance temperature is attained.
