5686 Glass Capsule SPRT
-260°C to 232°C Thermometer

Applications
Sometimes you would like to make SPRT measurements but traditional SPRTs are too long or awkward for a particular application. The Hart Scientific miniature glass capsule SPRT is perfect for Cryogenics, Calorimetry, and other metrology work requiring small SPRTs.

Features

• Temperatures from -260°C (13k) to 232°C.
• Stability typically 0.001°C over a 100°C range.
• Miniature capsule package eliminates stem conduction.

Description
These are true SPRTs. The high-purity platinum wire is hand-wound on a glass cross frame in a strain-free design. The glass capsule is designed to match the thermal expansion of the platinum wire to ensure a true seal at all operating temperatures. The capsules are pressure sealed and come protected in their own maple cases. The model complies completely with ITS-90 requirement for platinum purity including the following resistance ratio:

W(302.9146k)≥1.11807
and
W(234.3156k)≤0.844325

The 5686 covers temperatures from -260°C to 232°C, so it's perfect for cryogenic applications. It is 5.8mm in diameter and 56mm long. This SPRT is small but meets customary SPRT performance for reproducibility, reliability, and stability.

Specification

Description

Temperature Range

-260°C to 232°C. (13k to 505k)

Nominal R_TPW

25.5Ω

Resistance Ratio

W(302.9146k)≥1.11807
W(234.3156k)≤0.844325

Drift Rate

<0.005°C per year over the entire range

Self Heating at TPW

<0.002°C under 1mA current

Reproducibility

±0.001°C or better

R_TPW Drift after Thermal Cycling

<0.001°C or better

Filling Gas

Helium

Lead Wires

Four platinum wires, 30mm long

Size

5.8mm diameter x 56mm long

Ordering Information

Hart 5686-B

Glass Capsule SPRT, -260°C to 232°C, with Maple carrying case.