Traceable to ITS-90 and EN60751

• Calibration is needed for high accuracy or for verification  to third party.
• Calibration of RTD sensors
  1. The sensors are compared at -195 °C, -75 °C, 0 °C and  100 °C with traceable references.
  2. A certificate with measurements, calculated Calendar  Van-Dusen coefficients, uncertainty and traceability is issued.
• Unique calibration
  Senmatic offer a unique calibrated 4-20 mA transmitter  – RTD sensor set.
• What does unique calibration mean?
  1. The RTD sensor is calibrated
  2. The transmitter is programmed with the Callendar  Van-Dusen coefficients
  3. The transmitter is calibrated by simulating the RTD  resistance at 3 points (4 mA, 12 mA and 20 mA)
  4. Certificates for both calibrations are supplied together with the paired transmitter-sensor set
• Callendar Van-Dusen coefficients?
   The resistance at temperature t can be described this way R(t) = Ro*( 1 + A*t  +  B*t2 + C*(t-100)*t3) where  Ro is the resistance at 0 °C and A, B and C the Calendar Van-Dusen coefficients. Above 0 °C C=0. By active use of the coefficients the sensors uncertainty is less than ±0.024 °C in the calibrated range.
• Calibration is only offered with 4 wire sensors