5698-25 Working Standard SPRT
Key features
- Conform to ITS-90 SPRT guidelines and have a typical drift rate of 0.003 °C.
- Calibration options by fixed point.
- 485-mm quartz sheath, this 25-ohm SPRT covers a temperature range from –200 °C to 670 °C.
- Long-term drift isless than 6 mK—typically less than 3 mK.
Product overview: 5698-25 Working Standard SPRT
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True Standard Platinum Resistance Thermometer for Reliable Laboratory Performance
Accurate, Trusted, and Fully Specified for Your Lab
The Fluke 5698-25 Working Standard Standard Platinum Resistance Thermometer (SPRT) is designed for those who demand uncompromising accuracy, stability, and transparency in their laboratory temperature standards. Fully compliant with ITS-90 requirements and meticulously engineered for long-term reliability, the 5698-25 is the ideal choice for transferring standards from calibration labs to working labs and for supporting critical measurement processes.
Key Features and Benefits
- True ITS-90 Standard – Meets the full resistance ratio requirements for SPRTs under the International Temperature Scale of 1990 (ITS-90), ensuring the highest level of traceability and measurement confidence.
- Wide Measurement Range – With a temperature range from –200 °C to 670 °C, the 5698-25 covers most laboratory, industrial, and research calibration needs.
- Exceptional Stability and Low Drift – Typical long-term drift is less than 3 mK (and guaranteed below 6 mK) at the triple point of water after 100 hours at 670 °C—ensuring reliable performance over time.
- Strain-Free Platinum Sensor – The sensing element is made from high-purity platinum wire, wound in a completely strain-free configuration on a fused silica cross frame, then annealed and tested for optimum stability.
- Robust, Sealed Construction – Features a 485-mm fused silica sheath, pressure sealed with a special argon/oxygen gas mix, convection prevention discs to reduce stem errors, and a terminal box handle with strain relief. Wires are terminated with gold-plated spade lugs for secure connections.
- Easy Compatibility – Works seamlessly with Fluke 1594A/1595A Super-Thermometer, 1560 Black Stack, or 1529 Chub-E4 Thermometer readouts, thanks to its standard 25-ohm resistance and 1 mA excitation current requirement.
- Flexible Calibration Options – Available with or without calibration. Calibrations are performed in Fluke’s NVLAP-accredited lab using fixed-point or comparison methods, providing full ITS-90 traceability and maximum value for your investment.
Designed as a Working Standard
- What is a Working Standard? – A working standard is used to transfer the ITS-90 from a national or standards laboratory to your facility. The 5698-25 is carefully calibrated against intrinsic references, making it the backbone of your lab’s traceability chain.
- Application Flexibility – Suited for both standards transfer and daily calibration tasks, with robust construction to withstand routine use in busy calibration environments.
Transparent, Reliable, and Supported
- Full Performance Specifications Provided – Unlike some manufacturers, Fluke publishes complete specifications for the 5698-25, so you know exactly what you’re getting before you buy.
- Comprehensive Support – Benefit from Fluke Calibration’s renowned post-purchase support and calibration service options, ensuring your working standard maintains the best possible performance for years to come.
Specifications: 5698-25 Working Standard SPRT
Specifications | |
Temperature Range | –200 °C to 670 °C |
Nominal RTPW | 25.5 Ω (± 0.5 Ω) |
Current | 1.0 mA |
Resistance Ratios | W(234.315 K) ≤ 0.844235 W(302.9146 K) ≥ 1.11807 |
Sensitivity | 0.1 Ω/°C |
Drift Rate | < 0.006 °C/100 hours at max temperature (typically < 0.003 °C) |
Self-heating at TPW | < 0.002 °C under 1 mA current |
Reproducibility | ± 0.0015 °C or better |
RTPW Drift After Thermal Cycling | < 0.001 °C |
Diameter of Pt Sensor Wire | 0.07 mm (0.003 in) |
Protective Sheath | Quartz Glass Diameter: 7 mm (0.28 in) Length: 485 mm (19.1 in) |
Lead Wires | Four sensor wires |