eXacal Precision Thermometers
Table of Contents
Resistance Thermometers and Thermocouples
eXacal precision thermometers measure precise temperatures from −200 °C to 1200 °C and serve as a reference for the calibration of other thermometers. Depending on the application, they are available as Standard Platinum Resistance Thermometers (SPRT), Pt100 resistance thermometers, or precious metal thermocouples.
We manufacture them by hand in our manufactory in Fulda: from design and construction of the temperature sensor to accredited calibration according to DIN EN ISO/IEC 17025 (DAkkS).
Highlight · High End · ITS-90
Primary ITS-90 SPRT – Our High-End Thermometer
-200 °C to 670 °C
The primary Standard Platinum Resistance Thermometer meets all requirements of the ITS-90 (International Temperature Scale of 1990).
It is designed for maximum accuracy and thus represents the highest level of precision thermometry – ideal as a primary calibration standard in research, national metrology tasks, and wherever the lowest possible measurement uncertainty is required.
Secondary SPRT – The Robust Alternative for Daily Laboratory Use
The secondary SPRT is the more durable alternative for daily use in the laboratory.
It does not meet all ITS-90 requirements but still offers excellent accuracy and long-term stability.
This makes it the right tool for all demanding everyday applications where a stable, reliable, and less sensitive SPRT is required.
Our secondary SPRT models at a glance:
Secondary SPRT Reference Thermometer
(-200 °C to 250 °C)
Secondary SPRT Reference Thermometer
(-100 °C to 430 °C)
Secondary SPRT Reference Thermometer
(-100 °C to 670 °C)
Precision Thermometers
Our precision thermometers are ideal as a temperature standard for calibrations or for accurate temperature measurements. Available as resistance thermometers (Pt100) and as precious metal thermocouples of types R/S/B, Pt/Pd, and Pt/Au. Our eXacal precision thermometers are a robust alternative to the extremely sensitive ITS-90 Standard Platinum Resistance Thermometers (SPRTs). The eXacal thermocouples are manufactured with a stainless steel reference junction.
Industrial Reference Thermometers
Industrial Reference Thermometers (Pt100 and precious metal thermocouples) are perfectly suited for industrial use in traceable temperature measurements or as secondary standards in industrial calibrations (for example, in a dry-block calibrator).
Models:
Pt100
Pt100 Model I (-100 °C to 250 °C)
Pt100 Model IN (-100 °C to 400 °C)
Pt100 Model IH (-100 °C to 660 °C)
Precious Metal Thermocouples
Thermometers for Special Applications
Custom Designs: We also manufacture precision thermometers according to your individual requirements, such as differential thermometers, angled temperature probes, and thermometers based on specific customer requests.
Models:
Precision Thermometer Pt100 Model M (-100 °C to 250 °C) for immersion depth studies and rapid measurement
Type R / Type S Temperature Differential Thermocouple (0 °C to 1200 °C)
Pt100 Type D Temperature Differential Thermometer (-100 °C to 250 °C)
Do you have questions about our precision thermometers?
Speak directly with our expert!
Your contact person for precision thermometers:
Elke Seewald
Head of the eXacal Manufactory at Klasmeier
Thermometer Manufactory – Handcrafted Precision Thermometers
Our eXacal precision thermometers are in our manufactory in Fulda, Germany, with the utmost care handcrafted – and can be customized to your individual requirements upon request. Whether it is adjustments to the handle, connectors, probe length, or connection cable – we implement your wishes with precision.
Our thermometers are developed for exact temperature measurements and, depending on the model, cover a wide temperature range from -200 °C to 1200 °C.
In addition to thermometer design, we place special emphasis on developing our own tools and innovative production processes. From design and manufacturing to the final accredited calibration according to DIN EN ISO/IEC 17025 (DAkkS), every step takes place exclusively in-house. Thanks to the use of high-quality raw materials and the avoidance of external suppliers, we guarantee consistently high quality for our products.
Watch the video for a tour of the thermometer manufactory:
Overview of the Manufacturing Process
Mechanical Production
Components such as handles or prototypes for development projects are precisely manufactured using machining processes.
Precious Metal Welding Process
Thermocouple wires and connection cables are manually welded with the highest precision. The fuel gases required for this, hydrogen and oxygen, are not stored in cylinders but are generated directly from water by electrolysis in an optimal mixing ratio of 2:1. This process ensures particularly high purity of the fuel gas.
Laser Welding
Filigree connections, such as the lead wires of temperature sensors, are welded under a microscope using high-precision lasers.
Thermal Treatment of Thermocouple Material
A core competence is the targeted thermal treatment of thermocouple wires. Our aging processes ensure a metallurgically stable and thermoelectrically homogeneous state for eXacal thermocouples.
Aging of Resistance Thermometers
Resistance thermometers are fully stabilized in a specially developed aging furnace flushed with oxygen, following customized aging cycles.
Winding Wire Coils
For SPRT measuring resistors, ultra-thin, high-purity platinum wire is precisely wound into the finest wire coils using a specially developed winding machine.
Cleaning of Ceramic Components in a Tube Furnace
All ceramic components used in our precision thermometers undergo an intensive cleaning process in a tube furnace at high temperatures before use.
Temperature Sensors – Precision from In-House Production
The production of temperature sensors is a craft that requires the highest precision and expertise. In our manufactory, we combine state-of-the-art technology with traditional craftsmanship to carry out this complex process entirely ourselves. With great care and experience, our specialists manually thread ultra-fine platinum wire onto ceramic or quartz support bodies under a microscope. Previously, the wire is formed into a filigree coil on a winding machine, which serves as the basis for our highly sensitive temperature sensors. These delicate components form the heart of our products. In our thermometer manufactory, they are further processed and refined into precision thermometers of the highest quality – for exact measurement results you can rely on.
Modern 3D Printing Technology
High-precision insulation elements and complex plastic components, such as strain reliefs, are used in our eXacal thermometers. These components are manufactured directly in our production facility using state-of-the-art 3D printing technology. This allows even demanding geometries to be implemented without additional tools or manual intermediate steps. This not only saves time and costs but also enables flexible and customer-specific production of our thermometers using a modular design.
Inhomogeneity Scanner
The investigation of possible inhomogeneities in eXacal thermocouples is carried out with a specially developed inhomogeneity scanner. A movable heat source checks the entire thermocouple material of the measuring point for local deviations.
The inhomogeneity scanner is an innovative in-house development by Klasmeier and contributes significantly to the optimization of eXacal thermocouples. It enables:
A more realistic assessment of measurement uncertainties
The verification and refinement of thermal treatment processes
A significant improvement in product quality and manufacturing processes
eXacal Technology
eXacal precision thermometers have been developed from the ground up. Every component was designed with the greatest care and perfectly matched to the others. A central highlight is the innovative handle, which serves as a central technology carrier. Thanks to its modular design, it allows for a wide variety of eXacal thermometer combinations.
The Handle as a Technology Carrier
Our eXacal thermometers can be assembled almost arbitrarily as a modular system. This is made possible by our aluminum handle, which is fitted with an individually 3D-printed insert for each thermometer. Important components such as strain reliefs, protective gas fillings, or various protection tubes can thus be freely combined.
Temperature Sensors
Temperature Sensors from In-House Production
We manufacture precise temperature sensors in our manufactory. Experienced employees wind platinum wire onto ceramic or quartz bodies. After winding, we form these measuring resistors into precision thermometers.
Thermometer Wire
We use precious metals as thermometer wire for the measuring resistors and in the capillaries, rather than standard sheathed wires. Depending on the temperature range, these are pure silver or platinum. This allows us to reduce thermoelectric effects and parasitic voltages within the thermometer.
Protection Tubes
Protection tubes are selected based on thermal stress and the nature of the atmosphere. To optimally protect the temperature sensor from mechanical and chemical influences, protection tubes made of pure ceramic, precious metals, high-temperature alloys, or sapphire are used depending on the application.
Connection Cables
Connection cables for thermocouples and resistance thermometers are assembled by hand. We use copper strands made from a low-stress copper alloy specifically cast for our thermometers. A reinforced textile jacket made of heat-treated fiberglass protective sleeving, which is high-temperature resistant, serves as the insulation. This protects the individual strands from mechanical stress, high temperatures, and organic solvents.
High-Quality eXacal Carrying Case
All eXacal thermometers are delivered in a case, but can alternatively be ordered with a high-quality aluminum carrying case. The robust case with a customized foam insert ensures that the sensitive thermometers are well protected during transport and storage.
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