Alternative Ceramic Tubewells

 

Material	Chemical Symbol	Operating Temperature	Remarks
Sintered Alpha	SASiC	3000° F (1650° C)	No free silicon, higher density than SiC, low porosity, excellent Silicon Carbide thermal shock resistance, high chemical, corrosion and abrasion resistance. Excellent thermal conductivity.
Silicon Carbide	SiC	3000° F (1650° C)	Excellent thermal conductivity, corrosion resistance and abrasion resistance, good thermal shock resistance.
Fused Quartz	SiO2	3050° F (1677° C)	Excellent thermal shock resistance, unreactive to most acids and metals, performs well in oxidizing, inert or neutral atmospheres.
Mullites	3Al2O3•2SiO2	2750° F (1510° C)	Low thermal expansion, good thermal shock resistance, excellent mechanical strength.

 

 

Tolerance of Thermocouples

 

	°C			°F
ANSI/ASTM	Temperature Range	Standard	Special	Temperature Range	Standard	Special
R or S	0° to 600° 600° to 1480°	±1.5° ±0.25% T	±0.6° ±0.1% T	32° to 1112° 1112° to 2700°	±2.7° ±0.25% (T-32)	±1.08° ±0.1% (T-32)
B	870° to 1700°	±0.5% T	±0.25% T	1600° to 3100°	±0.5% (T-32)	±0.25% (T-32)
C*	0° to 426° 426° to 2315°	±4.4° ±1% T	-	- 32° to 800° - 800° to 4200°	±8° ±1% (T-32)	-

 

* Formerly Conax Technologies Type W5, Type C not an ANSI official designation.

Thermocouple Characteristics

 

			Color Coding
ANSI/ASTM	Symbol Single	Generic Names	Individual Conductor	Overall Jacket Extension Grade Wire
S	SP SN	Platinum 10% Rhodium Platinum	Black Red	Green
R	RP RN	Platinum 13% Rhodium Platinum	Black Red	Green
B	BP BN	Platinum 30% Rhodium Platinum 6% Rhodium	Gray Red	Gray
C	P N	Tungsten 5% Rhenium Tungsten 26% Rhenium	Green Red	Red