5698-25 Working Standard SPRT
The 5698 Working Standard SPRT is a true SPRT. It meets the ITS-90 ratio requirements for SPRTs and includes a Hart-designed, completely strain-free platinum sensor. With a 485-mm quartz sheath, this 25-ohm SPRT covers a temperature range from –200 °C to 670 °C. Long-term drift, which we define as the change in output resistance at the triple point of water after 100 hours at 670 °C, is (after converting to temperature) less than 6 mK—typically less than 3 mK.
The 5698 is the perfect companion to a Fluke 1595A Super-Thermometer, which reads 25-ohm SPRTs to within 0.015 mK at 0 °C and includes a number of convenient features for working with SPRTs. Requiring 1 mA of excitation current, the 5698 can also be used easily with a Fluke Black Stack, or even a Chub-E4 Thermometer.
If you need your SPRT calibrated by a reputable calibration lab, we offer appropriate calibration options by fixed-point in our NVLAP-accredited lab. Our calibration prices are as reasonable as our instrument prices, so you get maximum value from your SPRT.
Why buy critical temperature standards from companies unwilling to publish complete specifications? At Fluke Calibration, we not only provide excellent post-purchase support so you have the best possible ownership experience, we also provide you all the information we can before you purchase—including detailed performance specifications.
Maybe there is some art mixed with our science. But that doesn’t mean we keep secrets. Trust your lab standards to Fluke Calibration.
SPRTs. Art or science? It takes, in fact, quite a bit of both. The one thing not involved is mystery. That’s why Fluke Calibration SPRTs always include detailed published specifications, including drift rates.
Our newest SPRT is no exception. It was designed by the same Hart metrologists who have created a dozen different SPRT designs used in national labs around the world. And it performs just like we say it does.
|Temperature Range||–200 °C to 670 °C|
|Nominal RTPW||25.5 Ω (± 0.5 Ω)|
|Resistance Ratios||W(234.315 K) ≤ 0.844235
W(302.9146 K) ≥ 1.11807
|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|
|1912-4-7||PRT Calibration, –200 °C to 660 °C, NVLAP Accredited|