Thermocouples are one of the most commonly used temperature sensors. They are available in a wide range, each developed with specific characteristics, durability, resistance and temperature range to solve a particular application challenge. Here we look at two of the tungsten thermocouples, Type C and Type D. These have been developed to facilitate ultra-high temperature measurement in vacuum, reducing or inert atmospheres.
These thermocouple wires are both Tungsten Rhenium alloys. Type C is Tungsten 5% Rhenium vs Tungsten 26% Rhenium. Type D has a slightly different composition: Tungsten 3 % Rhenium vs Tungsten 25% Rhenium. Both of these thermocouples can be used for guaranteed temperature measurement up to 2871°C.
These two thermocouples are very similar in composition, ductility and performance. The only slight differences are that the average EMF of Type D is marginally higher than that of Type C. Furthermore, Type C is the only ASTM approved tungsten thermocouple while “Type D” is in fact an industry term and not an official standard thermocouple letter designation.
Type C (W5Re/W26Re) thermocouples are by far the most commonly used. However, there are some applications where Type D is specifically requested by customers. Kamet is able to supply both types from our webshop.
Tungsten thermocouples are the ideal choice for high temperature vacuums as well as either hydrogen or other inert gas environments. They are specifically selected for temperatures and conditions beyond the capabilities of platinum. Avoid usage of Type C and Type D thermocouple wires are in the presence elevated temperatures in oxygen, nitrogen or hydrogen due to embrittlement
Vacuum furnaces at extreme temperatures are one of the most common applications of these thermocouples. Others include:
Together with our partner and expert manufacturer, Concept Alloys, Kamet offers a variety of high quality Type C and Type D thermocouple via our webshop with two week delivery time. Our products offer the following advantages:
Depending on the demands (environment and temperature) of the application, these thermocouples can be used bare, with ceramic insulators or in mineral insulated (MI) cable with a metal sheath. All these variations are available in our webshop or through a custom order. To ensure accuracy and durability it is essential to make a thorough assessment of the application so that the correct configuration of insulators, wires and atmosphere is achieved. The in-house experts at Kamet are able to support and advise you in this process.
Download the product sheet op Type C and Type D thermocouple for the mechanical and physical properties.
Tungsten Rhenium Alloys datasheet
Based in the United States and founded in 2002, Concept Alloys is our partner for Tungsten Rhenium thermocouple wire. Concept Alloys are widely known for their proprietary testing and calibration methodologies used to routinely calibrate each end of every coil produced. This expertise and commitment to quality is further reflected in the fact that every finished coil has to meet their own end-to-end uniformity tolerance every 100°C, from +100°C to +2300°C. They have extensive experience in Tungsten Rhenium alloys and have built up unparalleled knowledge to provide great technical support. Furthermore, the company works with New Product Development teams in order to further knowledge on temperature measurement, and oxidation and corrosion resistance for Tungsten Rhenium alloys.
This commitment to quality, the focus on in-house expertise and innovative approach matches the business ethic of Kamet perfectly.
Kamet furthermore offers her customers:
Kamet Trading has a webshop stocked with items from our wharehouse. Please visit the webshop and browse through our available products. You can directly see the product details and request a quotation.