The AM1968 Platinum Capsule SPRT covers temperatures from -260°C to 100°C. The capsule construction makes this SPRT a preferred primary standard for cryogenic applications and other applications where space is limited or stem conduction is a concern for a long stem SPRT.

The sensing element is made of pure platinum wires with a temperature coefficient of 0.003925 Ω/Ω/°C. The coiled platinum wires are mounted in a way that is strain free and are enclosed in a platinum capsule, which is sealed by glass. The special sealing glass has a thermal expansion coefficient that matches with that of the platinum wire to ensure the capsule SPRT is sealed permanently through the entire temperature range. A uniquely designed support structure provides excellent performances with regards to stability, mechanical shock resistance, and thermal cycle performance. This SPRT achieves a high level of stability and repeatability in performance, and fully meets the ITS-90 criteria for reference thermometers.

Rtpw Drift of <1mK after thermal cycle

Temperature Range: -260°C (13K) to 100°C (373K)

Short-term Stability: <0.001°C at 0.01°C

Nominal Rtpw: 25Ω at 0°C

Fully meets the ITS-90 criteria for reference thermometers