SPI Supplies Brand Drilled Out Carbon Rods 2.25 x 0.125 in (57 x 3 mm) Pack of 25
| Availability | In Stock |
|---|---|
| Item | 01684-CF |
SPI Supplies® Brand Drilled Out Carbon Rods 2.25 x 0.125 in (57 x 3 mm) Pack (25):
SPI Supplies, like a lot of the rest of the world, has been calling their graphite rods "carbon rods". Putting it simply, a lot of users who are using what they call "carbon rods" have really been using graphite rods without realizing it. Since the resistivity of carbon and graphite, in general are quite different (the resistivity of carbon is much higher, typically about four times higher, but the exact resistivity will depend on the particular density of the rod), if a vacuum evaporator is configured for the resistivity associated with graphite, then it will work best on graphite and if a real carbon rod is substituted, then it will operate somewhat differently (in extreme cases, not at all). So you do want to be sure before ordering that you are indeed placing your order for the right kind of rod.
SPI Supplies rods, both carbon and graphite, are usually used for evaporating (and sometimes shadowing) carbon onto specimens being prepared for either x-ray microanalysis (EDS or WDS) or transmission electron microscopy (TEM). We offer two grades in graphite (spectroscopically pure and technical purity) and one grade in carbon (spectroscopically pure). We recommend the Spectroscopically Pure grade for demanding research applications, less than 6 ppm ash. For elemental analysis work, using either EDS or WDS, this is the grade we recommend, because one surely would not want impurity peaks entering their spectra from the impurities coming from the rods themselves.
For shadow casting, or teaching applications, where ultra-purity is not a pressing requirement, we believe the Technical purity would be just fine. But there is a caveat here: Some times the rods tend to get mixed up, and then people wonder why their rods "don't work any more". So for that reason, some laboratories try to restrict what is allowed into the facility to only to one or the other type of rod.
All SPI Carbon and Graphite Rods can be sharpened using either of two different styles of rod sharpeners.
Note: If you have been a customer of the SPI "carbon rods" in the past, make sure you order via the same order numbers. What you have been using was really graphite all along, and we apologize for any confusion the might have caused. Also, if you are involved with an SEM/EDS application, you might want to consider our high purity carbon (and graphite) fiber and thread.
Safety considerations:
Never, ever do a carbon rod or carbon fiber evaporation without eye protection. Protect yourself not only from the high intensity brightness of the rods, but also from UV radiation. Don't ever risk your eye sight to do a vacuum evaporation without eye protection. We recommend what are called "welders goggles".