1. What is a Pt1000?


Sensors such as the Pt1000 belong to a class of sensors called RTDs, or Resistance Temperature Detectors. These sensors have a strong temperature-dependent electrical resistance. By measuring the resistance of the PT1000, one can then calculate the temperature of the RTD.


The first part of the Pt1000, 'Pt', indicates that the sensor is Platinum-based. At 0°C, the second part, 1000, shows the nominal resistance of the sensor. As in this case, 1000Ω.

2. Benefits of using a Pt1000


  1. Temperature-resistance relationship is almost linear
  2. Non-degradable electrical resistance over time
  3. Excellent stability
  4. Very good chemical passivity
  5. High resistance to contamination


3. Standard sensor configuration


The standard configuration for all Rheonics sensors are based on the standard DIN EN 60751 for tolerance. The tolerance for different classes of RTD is as in the table below:


Tolerance ClassTolerance Value*
AA
A
B
C

Table 1. Tolerance class table for DIN EN 60751

 *abs(t)= absolute value of temperature in °C without regard to sign. 


4. What does this tolerance mean for Rheonics sensor?


Rheonics sensors by default use tolerance class B. 


The tolerance table can be used to estimate the tolerance from sensor measurement based on the temperature that it is reading. 


Here is an example:

If the temperature is -10°C, then the accuracy is 0.3+(0.005*10) = 0.35, it will be same at 10°C i.e., the accuracy at 10°C, or at -10°C is within ±0.35°C.



5. Ok, but now I want readings with a better tolerance than the one that you offer


Rheonics sensor are also delivered with Class A and Class AA tolerances.


These need to be ordered as an additional service and have an additional calibration surcharge. 


The DIN EN 60751 tolerance table (Table 1) is used and the procedure shown above is used to calculate the accuracy.


References


Rheonics SRV inline viscometer with inbuilt temperature sensor: https://rheonics.com/products/inline-viscometer-srv/


Rheonics SRD inline density meter with viscosity and temperature output: https://rheonics.com/products/inline-density-meter-srd/


Rheonics DVP probe style inline density and viscosity sensor for HPHT conditions: https://rheonics.com/products/inline-gas-lng-density-meter-dvp/


Rheonics HPHT inline viscosity and density sensor DVM with 3-in-1 measurements at HPHT conditions, all simultaneously: https://rheonics.com/products/hpht-pvt-density-meter-viscometer-dvm/