6.1 Mini-Rotary Viscometer, an apparatus that consists of one or more viscometric cells in a temperature-controlled aluminum block. Each cell contains a calibrated rotor-stator set. Rotation of the rotor is achieved by an applied load acting through a string wound around the rotor shaft.
6.1.1 The mini-rotary viscometric cell has the following typical dimensions:
6.2 Weights:
6.2.1 Yield Stress, weight set consists of ten 10 g units with a tolerance of 1 % for each unit.
6.2.2 Viscosity, 150 g weight with a 1 % tolerance.
6.3 Temperature Control System, that will regulate the mini-rotary viscometer block temperature in accordance with the temperature limits described in Table X1.1.
6.3.1 Temperature Controller is the most critical part of this procedure. A description of the requirements that the controller shall meet are included in Appendix X2.
6.3.2 Temperature Profile - The temperature profile is fully described in Table X1.1.
6.4 Thermometers, for measuring the temperature of the block. Two ranges are required, one graduated from at least +70 to 90°C in 1°C subdivisions, the other with a range from at least -36 to +5°C or -45 to +5°C, in 0.2°C subdivisions. Other thermometric devices of equal accuracy and resolution may be used to calibrate the temperature sensor.
6.5 Refrigeration Device, consisting of a means of removing heat from the instrument such that the cell temperature is controlled in accordance with the program described in Table X1.1.
6.6 Circulating System, that will circulate the liquid coolant to the instrument as needed. Methanol is a suitable coolant if the circulating coolant is below -10°C. One should observe toxicity and flammability precautions that apply to the use of methanol. The circulating system shall be capable of maintaining test temperature during the test. If methanol is leaking from the system, discontinue the test and repair the leak. (Warning - Methanol is flammable.)
6.7 Chart Recorder, to verify that the correct cooling curve is being followed, it is recommended that a chart recorder be used to monitor the block temperature.
6.8 Sample Pre-treatment Oven, an oven capable of maintaining a temperature of 80 +/- 1°C for a minimum of 2 h.
7. Reagents and Materials
7.1 Newtonian Oil, a low cloud-point of approximately 30 Pa·s (30 000 cP) viscosity at -20°C for calibration of the viscometric cells.
7.2 Methanol - Commercial or technical grade of dry methanol is suitable for the cooling bath.
7.3 Oil Solvent, commercial heptanes or similar solvent that evaporates without leaving a residue is suitable. (Warning - Flammable.)
7.4 Acetone - A technical grade of acetone is suitable provided it does not leave a residue upon evaporation. (Warning - Flammable.)