ASTM D1119 test method for percent ash content of engine coolants and antirusts
6. Apparatus
6.1 Crucible, high-silica glass, porcelain, or platinum of 50-mL capacity, equipped with cover.
7. Procedure
7.1 Ignite the crucible and cover over a Meker burner for 5 min and allow to cool to room temperature in a desiccator; then weigh to the nearest 0.1 mg.
NOTE 1 - Warning: When handling a hot crucible use proper caution and safety equipment such as safety glasses, gloves, tongs, etc.
7.2 Weigh 20 +/- 0.1 g of well-mixed antirust or coolant (Note 2 and Note 3), including all phases, into the crucible. Sample in accordance with Test Method D1176. Record the weight of the sample to the nearest 0.1 mg.
NOTE 2 - The weight of sample taken is suitable for most commercial products. If there is reason to believe that the ash content may be high, the sample size may be decreased to 5 or 10 +/- 0.1 g.
7.3 Place the covered crucible in a cool small sand bath in a vented hood. Raise the temperature by any convenient means until the liquid is evaporated. If the sample ignites, remove the heat source until the burning ceases; then reapply the heat.
NOTE 3 - Caution: Many types of coolant and antirust have tendencies to spatter upon heating, with consequent loss of sample and erroneous results. All precautions consistent with good laboratory practice should be followed.
NOTE 4 - Warning: Avoid inhalation of the fumes.
7.4 When the crucible appears dry, transfer the crucible to a support over a Meker-type burner. Ignite strongly at red heat until all carbonaceous material disappears from both crucible and cover. The crucible cover may be removed and carefully ignited, directly if desired, taking care to avoid losing any material deposited on the underside of the cover. Place the crucible and cover, with contents, in a desiccator to cool. When they have cooled to room temperature, weigh the crucible, cover, and contents (ash) to the nearest 0.1 mg. Proceed to 7.6.
7.5 If desired, muffle furnace ignition may be used in place of the Meker-type burner. If a muffle furnace is used, proceed as specified in 7.1 and 7.3, and then complete the procedure as follows: When the crucible appears dry, place the crucible and cover, with contents, in a muffle furnace. (To prevent losses from spattering due to rapid burning or volatilization of constituents, the muffle furnace shall be below 200°C when this transfer is made.) Raise the temperature at the maximum rate to between 750 and 900°C and ignite for 1 h at this temperature. Place the crucible and cover, with contents, in a desiccator to cool. When they have cooled to room temperature, weigh the crucible, cover, and contents (ash) to the nearest 0.1 mg.
7.6 Repeat the ignition and cooling until constant weight is obtained.
