Our Process & Standards
ISO/IEC 17025 accredited calibration with NIST-traceable results and ITS-90 compliance — documented uncertainty at every step of the measurement chain.
How Calibration Is Performed
Calibration Standards
Every temperature calibration is performed to the highest metrological standards in the industry. All measurement results are NIST-traceable, meaning each result is related to national standards through a documented, unbroken chain of calibrations with known and documented measurement uncertainties at every step. This chain of traceability ensures that readings from thermocouples, RTDs, infrared thermometers, and environmental chambers are defensible under audit and compliant with regulatory requirements.
Calibration procedures are aligned with the International Temperature Scale of 1990 (ITS-90), the internationally recognized standard defined by the International Committee of Weights and Measures (CIPM). ITS-90 establishes 17 fixed points based on phase transitions of pure substances—from the triple point of equilibrium hydrogen at −259.3467 °C to the freezing point of copper at 1084.62 °C—providing a reproducible framework for temperature measurement across the full operational range of industrial and laboratory instrumentation.
Our Story
Temperature Calibration Specialists was established to serve the manufacturing, pharmaceutical, food processing, and laboratory sectors across Illinois and Wisconsin. We recognized that businesses in Chicago, Milwaukee, Madison, Aurora, and throughout the region required access to rigorous, accredited temperature calibration without compromising on turnaround time or technical quality.
Calibration is performed under ISO/IEC 17025 accreditation and A2LA certification because precision demands accountability. From thermocouple and RTD calibration to environmental chamber validation and temperature mapping, every service is delivered under a quality management system designed to produce consistent, defensible results. We do not cut corners on quality—accreditation is not a marketing badge but an operational commitment to technical competence, impartiality, and continuous improvement in every measurement performed.
Standards & Method
Understanding Accreditation
ISO/IEC 17025:2017 is the international standard that specifies general requirements for the competence, impartiality, and consistent operation of testing and calibration laboratories. Accreditation to this standard requires a laboratory to operate under a documented quality management system with qualified personnel, validated methods, and properly maintained equipment. A complete uncertainty analysis is required for each calibration, and the accuracy of reference instruments used is maintained at a ratio sufficient to ensure valid results for the device under test.
A2LA—the American Association for Laboratory Accreditation—is an independent, non-profit accreditation body established in 1978. A2LA is recognized internationally and holds no affiliation with any industry or government agency, ensuring impartial assessment of laboratory competence. Accreditation through A2LA confirms that calibration work is evaluated by technical experts with direct experience in the relevant field of measurement, resulting in greater confidence in reported results.
The Method
Calibration is performed using a comparison method or fixed-point method, depending on the instrument type and the required level of uncertainty. For thermocouples, RTDs, thermistors, and temperature probes, instruments are placed alongside reference standards in a stabilized thermal environment—such as a dry block calibrator, liquid bath, or fixed-point cell—and readings are compared at multiple defined temperature points across the instrument's operational range.
For environmental chambers, ovens, furnaces, freezers, refrigerators, autoclaves, and incubators, temperature mapping is conducted using calibrated data loggers or reference sensors positioned at designated locations within the workspace. Uniformity and stability are evaluated against the manufacturer's specifications and applicable regulatory tolerances. Each calibration generates a certificate documenting the as-found and as-left readings, measurement uncertainties, reference standards used, and traceability information. All certificates are issued in accordance with ISO/IEC 17025 requirements.
Primary & Secondary Standards
The integrity of every calibration depends on the quality and traceability of the reference equipment used. Standard platinum resistance thermometers (SPRTs), calibrated against ITS-90 fixed-point cells, serve as primary reference standards for the most demanding temperature measurements. Secondary reference standards include precision RTDs, reference-grade thermocouples, and digital reference thermometers—each maintained under a controlled calibration schedule with documented uncertainty budgets.
Thermal sources used for calibration include dry block calibrators, stirred liquid baths, fluidized sand baths, and cryogenic systems, selected based on the temperature range and stability requirements of the instrument under test. All reference equipment is calibrated at intervals determined by historical performance data and drift analysis, ensuring measurement capability remains within stated uncertainties. Equipment records, calibration histories, and uncertainty analyses are maintained under an ISO/IEC 17025 accredited quality management system.
Schedule Your Calibration
Temperature calibration services are available for businesses and laboratories across Illinois and Wisconsin, including Chicago, Aurora, Joliet, Naperville, Rockford, Milwaukee, Madison, Green Bay, Kenosha, and Racine. Calibration is performed for thermocouples, RTDs, thermistors, temperature probes, infrared thermometers, pyrometers, thermal imaging cameras, digital and liquid-in-glass thermometers, bimetal thermometers, environmental chambers, ovens, furnaces, freezers, refrigerators, autoclaves, incubators, water baths, kilns, data loggers, chart recorders, temperature controllers, temperature transmitters, and reference thermometers.
All calibration certificates are issued with full NIST-traceable measurement results, documented uncertainties, and as-found/as-left data in compliance with ISO/IEC 17025. Expedited service and on-site calibration options are available based on instrument type and location. To schedule calibration or request a quote, use the options below.