| Zugriffsnummer | 20032 |
| Dokumenttyp | Konferenzartikel in Zeitschrift |
| Sprache | Englisch |
| Titel | Investigation of furnace uniformity and its effect on high-temperature fixed point perfromance [poster] |
| Autor(in); Institution |
Khlevnoy, B.; All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Moscow, RUSSIA
Sakharov, M.; All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Moscow, RUSSIA
Ogarev, S.; All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Moscow, RUSSIA
Sapritsky, V.; All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Moscow, RUSSIA
Yamada, Y.; National Metrology Institute of Japan (NMIJ), AIST, Tsukuba, JAPAN
Anhalt, Klaus; 7.3, Hochtemperatur- und Vakuumphysik, PTB-Berlin
|
| Quelle/Jahr | International Journal of Thermophysics: 29 (2008), 1, 271 - 284 |
| ISSN | 0195-928X (PRINT) ; 1572-9567 (ONLINE) |
| DOI | |
| Verlag | Dordrecht: Springer |
| Konferenzangaben | Tempmeko 2007, Lake Louise, 21-25, May, 2007, Canada |
| Zusammenfassung | High-temperature fixed points (HTFP) on the base of metal-carbon systems need furnaces with working temperatures as high as 2500oC (for Re-C) and even higher. Quality of a furnace, especially its uniformity, is very critical for reproducibility and plateau quality of the fixed points. Three types of furnaces are used for this application: Thermogage, Nagano and VNIIOFI-made BB3200pg/BB3500. The last one was originally designed as a variable temperature blackbody for spectral irradiance, and later adapted as a furnace for HTFP. This paper describes a new, BB3500YY, furnace that was designed and manufactured at the VNIIOFI specially for HTFP applications and then investigated at the NMIJ. The BB3500YY furnace has a design similar to the blackbody BB3200pg. It has a cylindrical heater consisting of a set of pyrolytic graphite (PG) rings surrounded by carbon cloth thermoshield. For better uniformity the BB3500YY, compared to its prototypes, has a longer set of PG rings as well as larger inner diameter of the rings. The HTFP cell is placed in the center of the heater supported be a holder. The design gives some advantages for further uniformity improving: the cell can be easily placed at any position inside the heater; numerous baffles can be put inside and out of the holder; different resistance ring order can be chosen to change the temperature gradient. The temperature uniformity of the BB3500YY was investigated and improved at the NMIJ. This paper shows that the resistance of the rings is the factor, which gives the most influence on the temperature distribution. By changing the rings resistance order the temperature gradient at the cell position can be minimized. Surrounding the holder by graphite cloth can also improve the uniformity. Finally a temperature uniformity after the investigations and improvements of the BB3500YY of 2 K within 40 mm and of 5 K within 80 mm for the central parts at a temperature of around 2500 oC was achieved. BB3500YY was used to observe melting plateaus of Re-C and TiC-C, which were definitely better than that observed in any other furnaces. For instance a NMIJ-made Re-C cell showed melting plateau with 0.1 K temperature range and about 40 minutes duration. |
Zitierung
Khlevnoy, B., Sakharov, M., Ogarev, S., Sapritsky, V., Yamada, Y., & Anhalt, K. (2008). Investigation of furnace uniformity and its effect on high-temperature fixed point perfromance [poster]. International Journal of Thermophysics, 29(1), 271–284. https://doi.org/10.1007/s10765-007-0347-z