Precise Calibration for All Resistance Thermometers – Flexible, Accredited, Reliable
We calibrate your resistance thermometers (temperature sensors such as Pt100, Pt25, etc.) and direct-reading measuring devices using state-of-the-art methods – either by comparison or fixed-point calibration. Our accredited laboratory (DIN EN ISO/IEC 17025) provides you with internationally recognized calibration certificates (DAkkS compliant) with individually tailored measurement uncertainties – precisely matched to your application.
Our Services
Accredited calibration of resistance thermometers and direct-reading measuring devices
Temperature range: -196 °C to +961 °C – full ITS-90 coverage
Calibration method: Fixed-point calibration at ITS-90 fixed points or comparison calibration
Proficiency testing according to DIN EN ISO/IEC 17043
Repair service for thermometers in our own manufacturing facility
Your Benefits at a Glance
Various Calibration Methods
The choice is yours:
Fixed-point calibration
at melting points
(economical, low measurement uncertainty)
Comparison calibration
(freely selectable measurement points, cost-effective)
Short Turnaround Times of 5 Business Days
→ Minimize downtime – your resistance thermometers are back in use quickly.
Low Measurement Uncertainties
→ Benefit from maximum precision:
We get the best out of your thermometer.
All from a Single Source
→ Complete package from calibration to proficiency testing to repair – all at Klasmeier.
Central Location in Fulda
→ Perfectly accessible – bring your thermometer in person or use our secure courier service.
Paperless Documentation
→ Available anytime, legally compliant signature.
Full transparency and security via our modern cloud solution.
Measurement Uncertainties for Accredited Calibration of Resistance Thermometers According to DIN EN ISO/IEC 17025 (DAkkS)
| Measurement Range | Method | Measurement Uncertainty |
|---|---|---|
| -189.3442 °C to 0 °C | DKD-R 5-1 Fixed Points: Ar, Hg, TPW | 5.5 mK |
| -38.8344 °C to 29.7646 °C | DKD-R 5-1 Fixed Points: Hg, TPW, Ga | 3.5 mK |
| 0 °C to 29.7646 °C | DKD-R 5-1 Fixed Points: TPW, Ga | 2.5 mK |
| 0 °C to 156.5985 °C | DKD-R 5-1 Fixed Points: TPW, In Melting Points | 5.5 mK |
| 0 °C to 231.928 °C | DKD-R 5-1 Fixed Points: TPW, In, Sn Melting Points | 7.0 mK |
| 0 °C to 419.527 °C | DKD-R 5-1 Fixed Points: TPW, Sn, Zn Melting Points | 12 mK |
| 0 °C to 660.323 °C | DKD-R 5-1 Fixed Points: TPW, Sn, Zn, Al Melting Points | 20 mK |
| Measurement Range | Method | Measurement Uncertainty |
|---|---|---|
| -196 °C | DKD-R 5-1 (DIN EN IEC 60751) in liquid nitrogen with equalization block | 15 mK |
| -180 °C to -80 °C | DKD-R 5-1 (DIN EN IEC 60751) in cryostat | 60 mK |
| -80 °C to -60 °C > -60 °C to 90 °C | DKD-R 5-1 (DIN EN IEC 60751) in calibration oven or liquid bath | 15 mK 10 mK |
| > 90 °C to 200 °C > 200 °C to 500 °C > 500 °C to 660 °C > 660 °C to 962 °C | DKD-R 5-1 (DIN EN IEC 60751) in calibration oven, liquid or solid bath | 30 mK 40 mK 50 mK 0.15 K |
Minimum Requirements for the Calibration of Resistance Thermometers
| Sensor Type | Temperature Range | Minimum Immersion Depth | Max. Diameter | Remarks |
| PRT | -196 °C | 300 mm | 8 mm | Nitrogen boiling point |
| PRT | -180 °C to -81 °C | 480 mm | 7.5 mm | Low-temperature cryostat |
| PRT | -80 °C to 230 °C | 100 mm | – | Calibration bath, good homogeneity |
| PRT | 231 °C to 700 °C | 300 mm | 8 mm | Calibration oven |
| PRT | 701 °C to 962 °C | 450 mm | 8 mm | High temperatures, greater depth required |
| Thermocouple | 196 °C | 300 mm | 8 mm | Nitrogen boiling point |
| Thermocouple | -180 °C to -81 °C | 480 mm | 7.5 mm | Low-temperature cryostat |
| Thermocouple | -80 °C to 230 °C | 100 mm | – | Calibration bath |
| Thermocouple | 231 °C to 1200 °C | 190 mm | 8 mm | Calibration oven |
| Au/Pt Pt/Pd | 0 °C to 1200 °C | 480 mm | 8 mm | Noble metal thermocouple |
Why Our Fixed-Point Calibration is Especially Reliable
We calibrate not only SPRTs but also all types of resistance thermometers at official ITS-90 temperature fixed points – with a clear goal: reliable, long-term stable measurement results for your applications.
Our process includes:
- Aging at maximum operating temperature
- Determination of aging drift at the triple point of water
- Investigation of self-heating errors and pressure effects
- Hysteresis testing and ITS-90 characteristic curve analysis
The result: A fully documented DAkkS-compliant calibration certificate that is internationally recognized – ideal for demanding applications and audits.
Calibration Possible from Small Immersion Depths
Thanks to our specially developed calibration method using slender temperature fixed points and our modern ISO-Tower technology, we can calibrate your resistance thermometers from an immersion depth of just 300 mm – with outstanding measurement uncertainty.
Comparison of SPRTs with IPRTs at Temperature Fixed Points
When calibrating reference thermometers at ITS-90 temperature fixed points, the question of the required calibration points often arises. To ensure that the number of ITS-90 temperature fixed points is sufficient even in the higher temperature range, we have conducted extensive investigations. The following graph shows the comparison of a Standard Platinum Resistance Thermometer (SPRT) with a reference thermometer as a result of these investigations.
The temperature difference shows that the maximum characteristic curve deviation of approx. 25 mK is within the measurement uncertainty. For accredited calibrations according to DIN EN ISO/IEC 17025 (DAkkS) in the higher temperature range, we also perform a plausibility check of the characteristic curve in addition to the aforementioned investigations. The test temperature is between the fixed-point temperatures.
Klasmeier Cloud Digital Archive:
Calibration documents quickly and easily accessible
The Klasmeier Cloud – the perfect filing system for all calibration documents. On all devices calibrated by Klasmeier, you will find a QR code that provides quick and easy access to our digital archive.
Especially practical: In addition to all calibration documents, you’ll also find the contact details of the respective Klasmeier contact person. This way, even five or more years from now, you can find the information you need with one click if you have questions about your calibrated product.
Klasmeier – because precise temperature measurement is a matter of trust.
Your Benefits in Detail:
In-house Manufacturing Repair Service
→ Thermometer repair directly with us – fast reliable
Proficiency Testing + Calibration + Consulting
→ All from a single source – fully auditable
Central Location in Germany
→ Easily accessible – or use our GO transport service
Digital, Signed Calibration Certificates
→ Always available, tamper-proof, legally compliant
Added Value for Audits Consulting
We can offer you support with audit preparations:
Accredited calibrations across the entire ITS-90 range
→ This ensures you are perfectly prepared for your next assessment.
Proficiency tests to confirm your measurement uncertainties
Practical tips and advice from an accredited laboratory
→ So that your temperature measurement technology convinces not only on paper, but also in everyday use
Together, We’ll Find the Right Solution for You
Speak directly with our expert!
Your contact person for calibration services
and proficiency testing:
Boris Kalb
Request Calibration
What are the costs for calibrating resistance thermometers?
If you have a platinum resistance thermometer (PRT) calibrated in our accredited calibration laboratory, the costs always consist of two components:
1. the basic costs for calibration
2. the costs per selected calibration point
Additionally, depending on the temperature range, nitrogen costs may apply.
1. Basic Costs (Mandatory component of every calibration)
- KK-1436 – Basic costs for comparison calibration for PRT: €150
The basic costs include:
• Creation of the accredited calibration certificate according to DIN EN ISO/IEC 17025 (DAkkS)
• Stabilization of the thermometer through thermal treatment
• Determination of self-heating and hysteresis (both documented in the calibration certificate)
• Review and evaluation by our specialists
2. Costs per calibration point
Depending on the temperature range in which you use your thermometer, suitable calibration points can be selected. We perform calibrations with a minimum of 3 calibration points – 5 calibration points are recommended for reliable characterization.
- kk-1476 – Calibration point -180 °C to -81 °C: €205
(additional nitrogen costs will be charged, see below) - kk-1437 – Calibration point -196 °C (nitrogen boiling point): €135
(additional nitrogen costs will be charged, see below) - kk-1438 – Calibration point -80 °C to +230 °C: €110
- kk-1439 – Calibration point +231 °C to +962 °C: €135
3. Nitrogen costs (only for low temperatures)
For calibrations in a cryostat or at -196 °C, the use of liquid nitrogen is necessary. This is charged as a flat rate per calibration: - kk-1477 – Nitrogen (50 l) for cryostat: €515 (for measurements in the range -180 °C to -81 °C)
- kk-1478 – Nitrogen (10 l) for -196 °C calibration: €105
4. Example Calculation
A typical PRT is calibrated at 5 calibration points, for example: - 0 °C, 100 °C, 200 °C, 400 °C, 660 °C
The costs are then calculated from: - €150 basic costs (kk-1436)
- 5 × €110–135 depending on the temperature range
- For a selection of 3 calibration points in the middle range (e.g., 0 °C, 100 °C, 200 °C), the cost is approximately €480 net.
5. Volume Discounts
If several thermometers are calibrated simultaneously at the same temperatures, we can offer you attractive volume discounts: - from 5 units: 15%
- from 10 units: 30%
Summary
The total cost of a calibration therefore depends on: - the one-time basic costs (kk-1436)
- the number and selection of calibration points (kk-1437 to kk-1439, kk-1476)
- nitrogen costs, if applicable (kk-1477, kk-1478)
