SECTION 1.0: INTRODUCTION
SPEX SamplePrep Freezer/Mills are cryogenic laboratory mills that cool samples to cryogenic temperatures, and pulverize them by magnetically shuttling a steel impactor back and forth against two stationary end plugs. Since the vial is closed, the integrity of its contents is maintained: hazardous or critical samples are easily controlled, cleanup is simplified, and cross- sample contamination is eliminated. Because the vial is immersed in liquid nitrogen throughout the grinding cycle, the sample is kept at cryogenic temperatures and its key aspects preserved. These features have made SPEX SamplePrep Freezer/Mills the most effective cryogenic mills in the world. They are the “mills of last resort” for many normally ungrindable samples, or samples whose composition or structure is altered by the heat generated by conventional grinding.
Before operating the 6870 Freezer/Mill, familiarize yourself with these instructions. The Freezer/Mill is different in its principles and operation from any other laboratory mill. If you’re familiar with the mill and want to proceed directly to grinding, Section 6.0 (PRACTICAL OPERATION) on p.14 can serve as a general review of the actual operation of the mill. We suggest unpacking the mill, then going over its various features with these instructions in hand before attempting to add liquid nitrogen or grind a sample.
OPERATING CONDITIONS: Do not set up the 6870 Freezer/Mill in an insulated or confined space. The Freezer/Mill should be run on an open countertop, in ambient air. If the entire mill is chilled during operation, components like the gas cylinders can fail. This damage is not covered by the Freezer/Mill warranty.
VERY IMPORTANT: Liquid nitrogen not only makes samples brittle through severe chilling, making them “grindable,” but also cools the magnetic coil which powers the 6870 Freezer/Mill. If the mill is operated without liquid nitrogen for a period of about one minute, the coil will become very hot and may sustain permanent damage. The 6870 Freezer/Mill has a liquid nitrogen sensor that should shut down the mill when the liquid nitrogen gets too low to cool the coil. Nevertheless the nitrogen level should be visually checked during extended runs as well as topped off before every run. The Freezer/Mill warranty does not cover damage to the coil caused by operating the mill with little or no liquid nitrogen.
SAFETY NOTES:
1)Liquid Nitrogen can be hazardous. Its boiling point is
2)Do not attempt to operate the 6870 Freezer/Mill without liquid nitrogen
Page 3 of 25 | SPEX SamplePrep LLC | 9.24.07 |
