ASTM D4305 Test Method for Filter Flow of Aviation Fuels at Low Temperatures
11. Procedures A and B
NOTE 4 - Procedures A and B are identical except that Procedure A uses the 26-µm test filter, while Procedure B uses the 42-µm test filter.
11.1 Set the RAMP control to a temperature approximately 5°C above the expected flow point of the specimen. If the flow point is unknown, set the control to a temperature warmer than any possible flow point.
11.2 Set the cooling rate control to 1.75°C/min.
11.3 Set the instrument to determine flow. Wait until the cell temperature is above 0°C.
11.4 Fill the syringe with 5 mL of sample, taking care not to introduce any air into the syringe.
11.5 Introduce the 5-mL specimen into the instrument through the integral sample filter, using the syringe. Leave the syringe in place attached to the sample filter.
11.6 The specimen will be rapidly cooled until its temperature reaches the ramp setting.
11.7 When the ramp temperature of the sample is reached, the cooling rate will change to 1.75 +/- 0.2°C/min.
11.8 When the no-flow point is reached (pressure greater than 1.33 kPa for longer than 0.95 s) the cooling will be switched off. The specimen will then be warmed at a rate of 1.75 +/- 0.2°C/min until the flow point is reached (pressure less than 1.33 kPa for longer than 0.95 s).
11.9 The instrument will display the flow temperature of the sample.
11.10 Follow the manufacturer's instructions to drain the sample and clean the syringe.