Secondary Reference PRT for the Most Demanding Calibration Applications

Tue 04.08.2026

The AccuMac AM1751 is a high-performance secondary reference platinum resistance thermometer (PRT) designed for precision temperature measurement and calibration across an exceptionally wide range from –200 °C to +670 °C. Combining outstanding stability, minimal drift, and a rugged Inconel® sheath, the AM1751 has become a trusted choice among accredited calibration and metrology laboratories seeking reliable, traceable, and repeatable temperature measurements.

AccuMac AM1751 - Secondary Reference PRT for the Most Demanding Calibration Applications

When maximum accuracy, long-term stability, and complete confidence in measurement results are required, the AccuMac AM1751 stands out as the ideal solution. This secondary reference platinum resistance thermometer (PRT) has been specifically designed for calibration laboratories and industrial metrologists who need a reliable reference standard across a wide temperature range, from cryogenic applications to high-temperature calibrations.The AM1751 is a preferred reference thermometer among accredited metrology laboratories worldwide, valued for its exceptional stability, low drift, and ability to deliver highly repeatable results even under demanding day-to-day operating conditions.

Key Specifications

• Measurement range: -200 °C to +670 °C
• Nominal resistance: 100 Ω at 0 °C
• Alpha coefficient: α = 0.003925 Ω/Ω/°C
• Accuracy (k=2):
  • ±0.015 °C at 0.01 °C
  • ±0.025 °C at -40 °C
  • ±0.035 °C at +420 °C
  • ±0.050 °C at +661 °C
• Short-term stability: better than ±0.007 °C
• Long-term drift: less than ±0.01 °C after 100 hours at 661 °C
• Hysteresis: ≤ 0.005 °C
• Thermal shock resistance: < 0.005 °C after 10 cycles between -200 °C and +670 °C
• Response time (t63): approximately 9 seconds
• Rugged Inconel® sheath construction
• ISO/IEC 17025 accredited calibration available

Why Choose the AM1751?
Exceptional Accuracy

The AM1751 delivers measurement uncertainties at the hundredth-of-a-degree level, making it an ideal reference probe for calibrating working standards, precision sensors, and temperature calibrators.

Outstanding Long-Term Stability

With extremely low drift and minimal hysteresis, the AM1751 maintains its metrological performance over years of use. This translates into fewer corrections, greater confidence in measurement results, and lower operating costs.

Robust Construction for Daily Use

The Inconel® sheath protects the sensitive platinum sensing element from mechanical damage and harsh temperature environments. As a result, the AM1751 is equally at home in both laboratory and demanding industrial applications.

A Proven Choice for Metrologists

Accredited calibration laboratories choose the AM1751 for its unique combination of accuracy, stability, and durability. It offers an excellent balance between a laboratory-grade SPRT and conventional industrial PRT sensors.

Typical Applications

• Calibration of temperature baths and dry-block calibrators
• Reference temperature measurements in accredited laboratories
• Calibration of industrial resistance thermometers
• Verification of temperature processes in pharmaceutical and healthcare industries
• Automotive, aerospace, and energy sectors
• Research and development laboratories

Available Configurations

• 12 in (305 mm)
• 20 in (500 mm)
• Bent configuration for specialized applications

Various connection options, smart connectors, and protective carrying cases are also available to ensure safe handling and easy identification of calibration data.

AccuMac AM1751 - A Reference Standard You Can Trust

If you are looking for a secondary reference PRT that combines laboratory-grade accuracy, long-term stability, and the robustness required for everyday use, the AccuMac AM1751 is a proven solution. That is why it can be found in the equipment portfolios of many accredited metrology laboratories, where it serves as a reliable foundation for precise temperature measurement and calibration.