Description
Low-Temperature Thermometer: The Robust Secondary SPRT Reference Thermometer for Accurate Temperature Measurements
Our low-temperature SPRT (Standard Platinum Resistance Thermometer) is a calibration standard for precision temperature measurements in the most demanding applications. Designed to meet the needs of research, industry, and quality assurance, these thermometers offer excellent accuracy and reliability. Due to their robustness, they are an attractive alternative to the often very delicate thermometers with quartz protection sheath for everyday measurement work.
Features of the Secondary SPRT Model 216:
Protective Gas Filling: The handle of the SPRT is gas-tight, allowing the thermometer to be filled with protective gas. This design shields the thermometer from environmental influences, enhancing its performance, especially at extremely low temperatures. The protective gas filling enables the thermometer to operate at temperatures as low as -200°C, allowing for calibration down to the argon triple point at approximately -189°C.
Temperature Range: With an operating range from -200°C to 250°C, our Secondary SPRT Reference Thermometer Model 216 covers a low-temperature range. This makes it a perfect solution for various measurement requirements.
Small Measurement Uncertainties: The precision of the thermometer is highlighted by its low measurement uncertainties, from just 4.5 mK to 7 mK with a DAkkS accredited calibration according to DIN EN ISO/IEC 17025. This high accuracy ensures reliable results across all areas of application.
Robustness: As a robust alternative to highly sensitive SPRTs (Standard Platinum Resistance Thermometers) with quartz sheath, our secondary SPRT reference thermometers are distinguished by their metal sheath and stable temperature detector. This makes them ideally for long-term use.
New SPRT Sensor: The newly developed SPRT temperature detector from Klasmeier has been improved in the following areas:
- Fast response time
- Low hysteresis
- Minimal self-heating
- Excellent reproducibility and stability
DAkkS-certified calibration of low-temperature SPRTs
In our in-house DAkkS-accredited calibration laboratory, we offer high-precision calibration services for low-temperature SPRTs. Our calibration ensures that each calibration is performed according to the internationally recognized standards of DIN EN ISO/IEC 17025, guaranteeing traceability to national and international standards.
Our secondary SPRT reference thermometer for low temperatures is specifically designed to be calibrated at temperatures down to the argon triple point. This enables its use in very low-temperature applications that require reliable temperature measurement.
| Temperature range | Method | Measurement uncertainty |
| -189,3442 °C – 0,01 °C | Argon to water | 6 mK |
| -38,8344 °C – 0,01 °C | Mercury to water | 6 mK |
| 0,01 °C – 29,7646 °C | Water to gallium | 6mK |
| 0,01 °C – 156,5985 °C | Water to indium | 6 mK |
| 0,01 °C – 231,928 °C | Water to tin | 7 mK |
What makes our calibration special?
Traceability: Through our DAkkS accreditation (DIN EN ISO/IEC 17025), every calibration is directly linked to national and international standards. This ensures that your measurement results are recognized worldwide.
Measurement Uncertainty: The accuracy of our calibration is based on a careful evaluation of all uncertainty components, including the reproducibility of the thermometer, the ITS-90 deviation function, self-heating, and the sensor’s hysteresis.
Application Range: With the detailed information from the calibration certificate, you can use your low-temperature SPRTs in the temperature range from -189 °C to 232 °C with complete confidence.
Technical data
| Technical data model 216 | |
| Model | eXacal 216 |
| Temperature range | -200 °C to 250 °C |
| Nominal resistance | Pt25 (ca. 25,5 Ohm) |
| Connection type | Four-wire |
| Connection | Bananaplugs |
| Sheath material | Metal |
| Thermometerwire | Platinum |
| Dimensions | |
| Handle | ⌀ 20 mm x 100 mm |
| Diameter sheath | ⌀ 6 mm |
| Length protective sheath | 400 mm |
| Filling protective sheath | Protective gas |
| Connection cable | 2 m |
| Max. immersion depth | 350 mm |
| Messwiderstand / Temperatursensor | |
| Length | 37 mm |
| Recommended measuring current | 1 mA |
| Self-heating | mA at the Gallium fixed point |
| W-value | W-Gallium ≥ 1.11807 (according to ITS-90 requirements) |
| Calibration | |
| Fixed-point calibration | Delivery with DAkkS calibration according to DIN EN ISO/IEC 17025 (see sample calibration certificate) or as traceable calibration with specification of WTP, W(Ga), and W(Sn) |