ASTM D5773 Standard Test Method for Cloud Point of Petroleum Products and Liquid Fuels (Constant Cooling Rate Method)
8. Sampling
8.1 Obtain a sample in accordance with Practice D4057 or D4177.
8.2 Samples of very viscous materials may be warmed until they are reasonably fluid before they are tested. However, no sample should be heated more than absolutely necessary.
8.3 The sample shall not be heated above 70 °C. When the sample is heated above 70 °C, allow the sample to cool below 70 °C before filtering or inserting into the apparatus.
8.4 When moisture is present in the sample, remove the moisture by a method such as filtration through dry, lint-free filter paper until the oil is perfectly clear, but make such filtration at a temperature at least 14 °C above the expected cloud point.
NOTE 5 - Moisture will be noticed in the sample as a separate phase or as a haze throughout the entire sample. Generally, a slight haze will not interfere with the detection of the wax cloud.
9. Preparation of Apparatus
9.1 Prepare the instrument for operation in accordance with the manufacturer's instructions.
9.2 Make liquid cooling medium connections if required (see Note 4) and ensure that they do not leak.
9.3 Make purge gas connections and ensure that they do not leak.
9.4 Turn on the liquid cooling medium if required (see Note 4).
9.5 Turn on the purge gas.
9.6 Turn on the main power switch ofthe analyzer. After the automatic self diagnostics startup sequence is completed, the instrument will display a READY message.
10. Calibration and Standardization
10.1 Ensure that all of the manufacturer's instructions for calibrating, checking, and operating the apparatus are followed.
10.2 A sample with a mutually agreed upon cloud point can be used to verify performance of the apparatus.
