5 Liberty St.
TABLE OF CONTENTS DESCRIPTION SECTION PAGE 1.0 Introduction..................................................................................................................................3 2.0 Specifications...............................................................................................................................4 3.0 Unpacking ....................................................................................................................................5 4.0 Setting Up .
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 crosssample contamination is eliminated.
SECTION 2.0: 6870 FREEZER/MILL SPECIFICATIONS Type of mill: cryogenic impact mill Grinding mechanism: steel impactor driven by dual electromagnets Coolant: liquid nitrogen Weight (empty, without vial or coolant): approx. 44 lbs. (20 Kg) Grinding Vials: one 6801 Large Vial, one Mid-Size Vial (6871, 6881, 6885), or one 6753 Microvial set, also one to four Small Vials (6751, 6751/52, 6761, 6771). Typical Sample Capacity: Small Vials: actual volume with impactor, approx. 25 ml.
SECTION 3.0: UNPACKING Inspect the exterior of the packing box and report any visible damage to the carrier. Remove all packing documents from the exterior of the box, and save them for your records. Open the top of the shipping box. Remove the packing material and accessories, and gently remove the Freezer/Mill. Visually check the mill for any damage that may have occurred during shipping. Unlatch the lid and inspect the interior of the tub, ensuring that it is free of any packing material.
870 FREEZER/MILL, BACK VIEW SECTION 4: SETTING UP The 6870 Freezer/Mill weighs 44 pounds (20 Kg) empty. The lid opens from the front and the lid latch is in the center. The AC Input module is on the back of the cabinet, and includes the power switch and fuse tray. The fuse tray can be opened with small screwdriver or knife-blade. Also on the back of the cabinet is the vent from the liquid nitrogen tub. There are gas cylinders on both sides of the cabinet to control the movement of the lid.
The control panel is a touch-screen, activated by a stylus. The Freezer/Mill is programmed and operated through this control panel, whose successive screens are described and illustrated in Section 5, starting on page 8. Programmable parameters include pre-cooling time, grinding time, cooling time between grinding periods, the number of grinding periods, and the rate of grinding. The control display also warns if the lid is not fully closed, or if there is not enough liquid nitrogen in the tub. 4.
4.4 Grinding Vial Sizes, Adapters, and Vial Openers. Large vials (6801, 6871) are run one at a time in the 6870 Freezer/Mill, without any adapter. Large vials are opened by the 6804 Extractor/Vial Opener, which is part of the 6870L Accessory Package. Mid-Size vials (6881, 6883, 6885) are run one at a time, but the 6886 Mid-Size Adapter must be placed in the coil first, to center and align any Mid-Size vial.
SECTION 5.0: TOUCHSCREEN DISPLAYS The 6870 Freezer/Mill is programmed and operated through a series of touchscreen displays. Transition between screens, and all programming and operating commands, are done by touching the screen with a stylus. Do not use a sharp point as this can damage or deface the screen. 5.1 LOGO SCREEN When you switch on the power, the LOGO screen appears first. This says “SPEX SamplePrep 6870 Freezer/Mill” and includes a graphic representation of the Freezer/Mill mascot.
6) Third cycle: the coil is activated for the final 2-minute cycle. When it is done, the program is over and the sample has been ground for a total of 6 minutes. 5.3 STATUS SCREEN To run the program displayed on the CURRENT SETTINGS screen, touch “Start SCRN.” This transfers you to the STATUS screen, which allows you to start the mill, stop it, or pause in the middle of a grinding program. (To change the settings, touch RTN on the STATUS screen to go to the CURRENT SETTINGS screen.
During the PRECOOL stage the TIME REMAINING line counts down the time for that stage in 5-second increments: 4:45, 4:40, 4:35, etc. After the PRECOOL stage comes the first GRINDING stage, and the screen displays STATUS: GRINDING. The TIME REMAINING line will display the time left in that grinding stage. If there are 3 grinding periods, during the first one the CYCLES REMAINING line will display 3 OF 3, during the second the CYCLES REMAINING line will display 2 of 3, etc.
impactor strikes both ends of the vial, a rate of 10 represents 20 impacts per second. The factory default setting for the rate is 10, and any saved program will revert to a rate of 10. To stop a program, touch STOP. The program will end. If RUN is pressed the entire program will start over. To pause during a grinding program, touch PAUSE. The STATUS screen will hold the settings at that moment (elapsed time, cycle, etc.), and the PAUSE “key” will darken. To resume the program, touch PAUSE again.
To store the new program on the CURRENT SETTINGS screen, or to recall a stored program to override the new program, touch STO/RCL to take you to the first of two STORE/RECALL screens: 5.5 STORE/RECALL SCREENS Rcl Sto PRESET O: FISH SCALES Lbl Rcl Sto PRESET 1: Lbl Rcl Sto PRESET 2: Lbl Rcl Sto PRESET 3: Lbl Rcl Sto PRESET 4: Lbl RETURN MORE FIRST STORE/RECALL SCREEN In this version of the screen, only Preset Program 0 has been stored and named.
As you touch the letter/number keys, what you have entered appears above the keyboard in a mini-screen with a centered cursor. The SHIFT key lets you shift back and forth from upper case to lower case. Touching the SPACE key advances the cursor one space. Touching the BACK key sends the cursor back one space. The CLEAR key clears whatever you have entered on the mini-screen. The ENTER key enters whatever appears in the mini-screen in the STORE/RECALL screen, as the name of the program where you touched Sto.
Note that there are three different sizes of vial that can be run in the 6870 Freezer/Mill: Large, Mid-Size, and Small. Mid-Size vials must be run with a 6886 Adapter in the coil, and Small vials must be run with a 6806 Adapter in the coil. Large vials do not need an Adapter. See Section 4.4 for details.
procedure for your own materials should be determined by trials; in practice almost no two materials grind alike. Avoid overfilling vials as this greatly reduces grinding efficiency. If at first the sample doesn’t grind as intended, try these strategies: • Reduce the overall weight of the sample. (Some fibers and thin films may grind best in the Small vial with a sample weight of 100-200 mg.) • Reduce the size of the individual pieces to ¼ or 1/8 inch (6 to 3 mm). • Increase the precooling time.
Accessory Packs can be placed in an insulated container to hold the vials upright during chilling. At the same time, chill an impactor separately. As soon as the submerged end of the vial is chilled, drop in the cold sample and then the chilled impactor. (Always wear insulated gloves when handling chilled vial components directly!) Now carefully insert the other end-plug, still warm, into the warm end of the cylinder.
6.32 Opening the Vials To open a vial, slip the open end of the appropriate Extractor/Vial Opener over a threaded endplug, align the pegs in the end-plug with the slots in the Extractor, and turn the knob clockwise until the end-plug is drawn out. If the end-plug is drawn out within a millimeter or two of the end of the center cylinder and stops, rock the Extractor gently to dislodge the end plug. Always be careful that the vial does not fall and spill its contents.
The impactor will have to be separated from the sample and can be handled with gloved fingers, a strong magnet, tongs, or pliers. Tools without a good gripping surface are likely to slip off the impactor. If some condensation on a cold sample is unacceptable, you can either wait for the sample vial to warm up before opening and emptying it, or open and empty a chilled vial in a glove box filled with dry nitrogen gas, argon, etc.
6.4 Checking The Liquid Nitrogen Level Every time you remove or insert a vial, note the level of liquid nitrogen (LN) in the tub. You should top off the LN when needed as a matter of routine. If your programmed grinding cycle includes more than twenty or thirty minutes of actual grinding time, you should visually check the nitrogen level at about that point and add more if needed.
Operation: when the 6870 Freezer/Mill is set up for the first run of the day, with a loaded vial in the coil, make sure the LN valve on the supply tank or line is open. Go to the STATUS screen and touch RUN. The Auto-Fill valve will open and let LN into the Freezer/Mill tub. The valve may close and open several times before the tub is full and Pre-Cool timing starts, but this is normal. LN boils and splashes as it enters the tub and this may temporarily “fool” the upper LN sensor.
temperature before attempting to clean it. Once the unit has attained room temperature, wipe down the unit as indicated previously. After every period of use, the mill is going to be wet with condensation since the Freezer/Mill will pick up moisture as long as it is cold. To maintain the exterior of the unit, first disconnect the Freezer/Mill. Then an occasional spraying and wiping down with a mild window cleaner or similar product will be sufficient.
7.04 Contacting SPEX SamplePrep LLC Within the United States, write, telephone, or e-mail us at: SPEX SamplePrep LLC 15 Liberty St. Metuchen, New Jersey 08840 Tel.: 732-549-7144 or 800-522-7739 Fax: 732-906-2492 Website: www.spexcsp.com E-mail: sampleprep@spexcsp.com Outside the United States, contact the SPEX SamplePrep representative from whom you bought our equipment. A list of our current representatives is on our website, above.
SECTION 8.
SECTION 9.0: TROUBLE-SHOOTING GUIDE, PAGE 2 OF 2 PROBLEM CAUSE SOLUTION 14 Blunt end-plug doesn’t come off room-temperature vial Hard to grip Warm vial under hot water. Use wide-jaw pliers if necessary.
