EXPLANATION
These three test methods are alternative procedures with automatic apparatus to Test Method D2500. When specifications quote D2500, do not substitute these test methods without obtaining comparative data and customer agreement. All three methods are more precise than Test Method D2500. All three test methods cover the range from -40+ 49° C with a temperature resolution of 0.1° C.
D5771 - ISL Instrument
After insertion of the specimen into the apparatus, and the initiation of the program, the specimen is cooled according to the cooling profile listed. The specimen is continuously monitored by an optical system for the formation of a crystalline structure. When the crystallization of the wax in the specimen is detected by the optical system, the temperature is recorded to within 0.1° C resolution. The specimen is then heated to facilitate the start of the next test.
D5772 - Herzog Instrument
After insertion of the specimen into the apparatus and initiation of the program, the specimen is heated and then cooled at a specified rate. The specimen is continuously monitored by an optical light barrier for the crystal structure formation. The temperature when the crystallization of the wax in the specimen is detected by the optical barrier is recorded with a resolution of 0.1° C. The specimen is then heated to the original starting temperature.
D5773 - Phase Technology Instrument
A specimen is cooled by a Peltier device at a constant rate of 1.5±0.1° C / min while continuously being illuminated by a light source. The specimen is continuously monitored by an array of optical detectors for the first appearance of a cloud of wax crystals. The detectors are sufficient in number to ensure that any solid phase hydrocarbon crystals that may form are detected. The temperature at which the appearance of a cloud of wax crystals is first detected in the specimen is recorded to 0.1° C resolution. When the recorded temperature is rounded to the next lower integer temperature, it is designated as the D2500/IP 219 equivalent cloud point per Test Method D5773.
TEST PRECISION
