Extreme Temperature Exotic Thermocouple Probes

OMEGA™ Exotic Thermocouple Probes are designed for use in extreme temperatures, up to 2315°C (4200°F). These probes utilize either Platinum/Rhodium (types R, S, or B) or Tungsten/Rhenium (types G, C, or D) elements, with a variety of insulations and sheath materials. Depending upon the sheath material selected, these probes may be used in inert, oxidizing, reducing or vacuum conditions. The maximum temperature is based on the lowest max. temperature of the element, insulation and sheath material. Five cold end probe terminations are available: replacement probe, subminiature or standard size ceramic connector, heavy-duty standard size, molybdenum-sheathed nylon connector, or transition joint with 72-inch lead wire.

Sheath Materials

Code	Material	Max. Operating Temp.	Working Environment	Approx. Melting Point	Remarks
XTA	Tantalum	2300°C 4200°F	Vacuum	3000°C 5425°F	Resists Many Acids and Weak Alkalies. Very Sensitive to Oxidation Above 570°F
XMO*	Molybdenum	2200°C 4000°F	Inert Vacuum Reducing	2610°C 4730°F	Sensitive to Oxidation Above 400°F Non-bendable
XPA	Platinum- Rhodium Alloy	1650°C 3000°F	Oxidizing Inert	1870°C 3400°F	No Attack by SO2 at 2000°F. Silica Is Detrimental. Halogens Attack at High Temp.
XIN	Inconel 600	1150°C 2100°F	Oxidizing Inert Vacuum	1400°C 2550°F	Excellent Resistance to Oxidation at High Temp. Hydrogen Tends to Embrittle. Very Sensitive to Sulfur Corrosion

*Refractory metals are extremely sensitive to any trace of oxygen above approximately 260°C
(500°F). Must be used in vacuum or in very pure inert gases such as Hellium or Argon.

Insulation Materials

Code	Material	Max. Operating Temp.**	Approx. Melting Point	Remarks
H	Hafnia (HfO2)	2500°C 4530°F	2830°C 5125°F	Nontoxic substitute for BeO. High Thermal Conductivity.
M	Magnesia (MgO)	1650°C 3000°F	2790°C 5050°F	Hygroscopic. Compacts Well.
A	Alumina (Al2O3)	1540°C 2800°F	2010°C 3650°F	Requires Considerable Volume Reduction to Compact Satisfactorily.

Note:
For temperatures above 1000°C (1800°F), all insulating materials experience a
substantial decrease in resistivity with increasing temperatures.

** Values given are for compacted insulation. For uncompacted hard-fired insulators,
useful temperature range can be 5 to 110°C (100 to 200°F) higher.
Molybdenum sheathed probes are not recommended in applications where they will be
exposed to carbon, including graphite.

For Graphite environments, Consult Omega’s Custom Engineering Department for Pricing and Delivery on Tungsten Coated Molybdenum sheathed T hermocouples.

Termination Style Q
Type OGP heavy-duty, color-coded male and female connectors. Add $10 to base price.
Termination Style TJ
Heavy-duty transition termination with 72-inch leads. Add $13 to base price.
Termination Style HX
Type NHX high temperature ceramic male and female connectors with color identification dot. Add $17 to base price.
Termination Style SX
Type SHX miniature high temperature ceramic male and female connectors with color identification dot. Add $11 to base price.
Termination Style RP
Replacement probe style with 1″ bare wire leads. No additional price.

Calibration1 Atmosphere2 Max.Temp3 Model Number C W-5% Re vs. W-26% Re V. 2300°C 4200°F XTA-W5R26-U-062-30-H-*-** XTA-W5R26-U-125-30-H-*-** XTA-W5R26-U-125-24-H-*-** R* Pt-13% Rh vs. Pt V. 1475°C 2700°F XTA-P13R-U-062-30-M-*-** XTA-P13R-U-125-24-M-*-** XTA-P13R-U-062-30-H-*-** XTA-P13R-U-125-24-H-*-** C W-5% Re vs. W-26% Re I.V.R. 2200°C 4000°F XMO-W5R26-U-125-30-H-*-** XMO-W5R26-U-250-30-H-*-** C W-5% Re vs.W-26% Re I.V.R. 1540°C 2800°F XMO-W5R26-U-250-30-A-*-** XMO-W5R26-U-062-40-A-*-** XMO-W5R26-U-125-30-A-*-** R* Pt-13% Rh vs. Pt I.V.R. 1480°C 2700°F XMO-P13R-U-125-30-A-*-** XMO-P13R-U-250-24-A-*-** C W-5% Re vs. W-26% Re O.I.V. 1540°C 2800°F XPA-W5R26-U-125-30-A-*-** R* Pt-13% Rh vs. Pt O.I.V. 1480°C 2700°F XPA-P13R-U-062-30-M-*-** XPA-P13R-U-125-24-M-*-** XPA-P13R-U-125-30-A-*-** C W-5% Re vs. W-26% Re O.I.V. 1150°C 2100°F XIN-W5R26-U-062-30-M-*-** XIN-W5R26-U-125-30-M-*-** R* Pt-13% Rh vs. Pt O.I.V. 870°C 1600°F XIN-P13R-U-062-30-M-*-** XIN-P13R-U-125-30-M-*-** XIN-P13R-U-125-24-M-*-** XIN-P13R-U-187-24-M-*-** XIN-P13R-U-250-24-M-*-** XIN-P13R-U-250-20-M-*-** * Specify Termination Style: Q, TJ, HX, SX, or RP ** Specify Probe Length in inches

Note 1:   Prices subject to change Please consult the Sales Department for current pricing. Note 2:   Atmospheres:   O-Oxidizing    I-Inert    V-Vacuum    R-Reducing. Note 3:   Maximum service temperatures shown are for probes with the largest available gage wire leads. Consult Engineering for ratings of other dimension probes. Note 4:   Bending: XPA sheathed probes with platinum elements be bent in the field. Note 5:   Some probes available in dual configurations. Check with Sales Department.