Precious (noble) metal and base metal thermocouples widely used in industries for the measurement of temperature in the range from low to ultrahigh temperatures. YAMARI manufactures a wide variety of quality products for use in general industry as well as explosive and hazardous areas. Unique to YAMARI our thermocouples are produced in a fully automated environment which houses some of the most up-to-date machinery in the world.

Base Metal Thermocouple Noble Metal Thermocouple
Type K, E, J, T, N R, S, B
Element Diameter 0.25, 0.5, 1.0, 1.6, 2.2, 3.2, 4.8, 6.0, 6.4, 8.0 0.3, 0.35, 0.4, 0.45, 0.5
Sheath Material SS 316, 310, 321, Inconel, Hastelloy X, Cupro-Nickel, Nicrobell Ceramic, Quartz, Recrystalized Silicon Carbide
Configuration Simplex, Duplex, Triplex, Multipoint Simplex, Duplex

Metal Sheathed Thermocouple (THERMIC)

Metal Sheathed thermocouple is comprised of metal sheath in which the thermoelectric elements are embedded in highly compacted magnesium oxide (MgO) insulation.

The construction guarantees a superb insulation quality and high resistance to pressure, and has, in addition, an excellent flexibility, which has been given to it by annealing in a proper method

Types of Thermocouple K, E, J, T, N, R
Sheath O.D. (mm) 0.25, 0.5, 1.0, 1.6, 2.2, 3.2, 4.8, 6.4, 8.0
Sheath Material SS316L, SS310S, Inconel 600
Class JIS Class 1, JIS Class 2
Pair Single, Double
Hot Junctions Type I(Grounded), Type II(Ungrounded), Type III(Exposed)

Standard Models of THERMIC Metal Sheathed Thermocouple (Model: TM)

Flange Nipple Type
Flexible Shield Lead Type
Metal Connector Type

Quick Connector Type
Screwed-in Plain Nipple Type
Terminal Head Type

Metal Sheathed Thermocouple (AD THERMIC)

A new type K thermocouple conductor was jointly developed with a world-class manufacturer of thermoelectric wire to improve long-term stability and service life at elevated temperature in reducing atmosphere. AD-THERMIC is a MI thermocouple cable comprising of this advanced thermocouple conductor and Inconel 600 sheath with MgO insulation. An excellent long-term stability and longer service life compared to the conventional MI thermocouple cables have been proven on our field test using heat treatment furnace and reducing furnace.


  • Excellent long-term emf stability in hydrogen and carburizing atmosphere at elevated temperature.
  • Prolonged service life in continuous operation.

HT-THERMIC Thermocouple

The demand for measuring very high temperature in research laboratories, specialized furnaces, and in other high temperature experimental and industrial applications has grown dramatically in recent years. In response to this demand, Yamari Industries has been providing its Tungsten Rhenium thermocouples and expert knowledge to customers needing accurate measurements of high temperatures in a wide range of fields. Now, Yamari is pleased to announce it has developed a new type of Tungsten Rhenium thermocouple, “VAC-Curate 2100”, in conjunction with a world class Japanese manufacturer of quality alloys and can supply thermocouple elements conforming to ASTM standard E988-96 in matched pairs.

Advantages of the Tungsten Rhenium Thermocouple

  • Compared to platinum elements, the tungsten rhenium thermocouple has a high and relatively linear thermal emf output.
  • Tungsten Rhenium can measure temperature over a range extending to 2,300?.
  • Noble metal thermocouples are usually used in oxidizing or inert atmosphere. Tungsten Rhenium thermocouples are suitable for use in reducing or inert atmosphere and in vacuum or nuclear environments.

Physical Properties of the VAC-Curate 2100

Melting point (?) 3375?? 3021??
Specific Gravity 19.4 19.6
Resistivity µO·cm(30?) 12.6 28.8
Coefficient of Expansion(0~100?) 4.6×10 -6 4.9×10 -6
Specific Heat (30?) 0.131 0.132

Multi-Point Thermocouple

For many critical processes from tall reactor vessels, catalytic crackers, flare stacks to small horizontal diffusion furnaces used in semi-conductor industry, monitoring of temperature profile and distributions at each required location is one of the most important parameters for efficient control and safety of the process. Our Multi-Point thermocouples are an ideal solution on such temperature measuring requirements, particularly in case the installation space is limited and yet reliability is of prime concern. Multi-Point Thermocouple assembly consists of already proven THERMIC Metal Sheathed Thermocouple units in calibrations of Types T, J, E, K and N up to 1200? with all grades of stainless steel, Inconel 600 and 625, Incoloy 825 sheath, etc. Outer protection thermowell, heat resistant terminal connections and dust or explosion-proof terminal enclosure can be supplied connected with extension neck and flange for the ease of installation even at hostile environments. Most of Multi-Point thermocouples are custom designed to the user’s specific requirements. Please consult factory specifying the model number, type of thermocouple, number of measuring point, protection sheath or tube material and dimensions.

Standard Designs of Multi-Point Thermocouple :
Free Hanging Type Generally consists of small diameter outer tubes and THERMIC Thermocouples. 2〜12 measuring points, Assembly length 20 meters max. Temperature readings may be affected by convection and radiation inside the protection tube. Economical but slower response and rather low accuracy. Not recommended for applications where continuous vibration is encountered.
Multi-Guide Plug Type Robust construction and most common for vessel and cracking tower. Each hot junction is held in a guide plug. 2〜10 measuring points, Assembly length 20 meters max. Long life and less maintenance. Better sensitivity and reasonable accuracy.
Spring or Thermostat Loaded Type A heat resistant plate spring or thermostat presses to contact each hot junction to inner wall of the protection tube. Rugged, stable construction. 2〜10 measuring points, assembly length 20 meters max. Reasonable life and less maintenance. Quicker response and good accuracy.
Swaged-in Type Numbers of THERMIC Metal Sheathed Thermocouples having different location of hot junction are oversheathed by heat and corrosion resistant alloy tube and then swaged down to an integrated tight multiple assembly of minimal heat mass. Smallest diameter assembly, recommended for narrow installation space. Can be bent for easy installation. Assembly length 30 meters max. 3〜20 measuring points, Robust, quick response, long service life and good accuracy.

High Temperature Multi-Pont Thermocouple

For temperature range of above 1200℃ upto 1450℃, where metal sheathed compacted MgO type thermocouple can no longer be used as well as any of superalloys, Platinum-Rhodium group thermocouples of Types S, R and B are used with high purity Quartz protection tubes and Alumina insulators. At present major applications of such a High Temperature Multi-point Thermocouple seems to be concentrated for use on measurement of temperature profile in a diffusion furnace of semi-conductor industry. Due to limitation of the furnace inlet, 2〜5 points assembly is prevailed. For special applications, Silicon Carbide outer protection tube can be used. Please consult our factory.

Standard Designs of High Temp. Multi-Point Thermocouple :
Straight Quartz or Alumina Tube protected Type
Protection Tubes High Purity Quartz, Alumina and Special SiC tube
Thermocouple Type R, S and B
Measuring points 2〜5 max.
Measuring range Type R and S 1200℃ (Quartz Tube), Type B 1600℃ (Alumina Tube)
Length of Assembly 1〜2 meters
Overall Dia. of Assembly 12〜25 mm.
Accuracy Standard Grade ±0.25% of Reading.
Premium Grade
±0.1% of Reading (Type R only)
*SiC tube is optional, but sometimes needs to protect thermocouple wires
from contamination by inner protective coating or clean Alumina inner tube,
Bent protection Tube Type Specifications are same as above, but the cold end of the protection tube is bent approx. 90 Deg. to fit for limited installation space.