Heating/cooling methods aluminum block

In the closed reflux spectrophotometric method (Standard Method 5220 D), a standardized colorimetric reagent, based on dichromate, is provided in a sealed vial. Test samples are added to the vial and heated to 150 °C for 2 h in an aluminum block with appropriate holes to accommodate the vials. After cooling, the... 

Finally, a method that is used to determine pitch volatility (ASTM D-4893) might also be used, on occasion, to determine the nonvolatility of mineral oil. In the method, an aluminum dish containing about 15 g of accurately weighed sample is introduced into the cavity of a metal block heated and maintained at 350°C (662°F). After 30 min, during which the volatiles are swept away from the surface of the sample by preheated nitrogen, the residual sample is taken out and allowed to cool down in the desiccator. Nonvolatility is determined by the sample weight remaining and reported as % w/w residue. 

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