Abstract
We describe a simple and low-cost apparatus for in-vacuum helium diffusion measurements that reduces temperature gradients, set point overshoot, and ramping times compared with conventional resistance furnace techniques. The sample, suspended by a thin wire in a vacuum chamber, is heated by radiation from an Al-coated projector bulb passed through a sapphire viewport. Because the total mass of the sample package being heated is small (typically <100 mg), thermal gradients and thermal inertia are both small. In experiments with set points between 100 and 750 °C, this apparatus can achieve set point from room temperature in ~90 s, usually with <3 °C of set point overshoot persisting for just a few seconds. Helium diffusion coefficient measurements indirectly indicate that temperatures are precise and reproducible to better than ±2 °C.
Original language | English (US) |
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Pages (from-to) | 2059-2061 |
Number of pages | 3 |
Journal | Analytical Chemistry |
Volume | 71 |
Issue number | 10 |
DOIs | |
State | Published - May 15 1999 |
Externally published | Yes |
ASJC Scopus subject areas
- Analytical Chemistry