Resistance Temperature Sensor

Abstract

A resistance temperature sensor with a first temperature sensor element and a second temperature sensor element, wherein the first temperature sensor element comprises a first measuring path and the second temperature sensor element a second measuring path, wherein the first and the second measuring paths extend on a substrate, wherein the substrate has an anisotropic thermal expansion with at least two mutually differing expansion directions (a, c), and wherein a projection of the first measuring path on the expansion directions (a) differs from a projection of the second measuring path on the expansion directions (c).

1 - 15 . (canceled) 
     
     
         16 . A temperature measuring device, comprising:
 two measuring transducers for monitoring a process variable in a process, which is occurring in a pipe or other container, each measuring transducer comprises a resistance temperature sensor; and   the measuring signals of the respective resistance temperature sensors are carried via connection lines and are supplied to a transmitter unit,   wherein:   said transmitter unit has two measurement signal inputs available, which are connected via cable to the corresponding connections of the measuring transducers; and   the measurement signals are evaluated by said transmitter unit and, in given cases, error reports are output in the case of drift of one of said measuring transducers or both of said measuring transducers.   
     
     
         17 . The temperature measuring device according to  claim 16 , wherein:
 a high accuracy of said temperature measuring device is achieved by sensor-transmitter-matching, e.g. by using the Callendar-van-Dusen equation.   
     
     
         18 . The temperature measuring device according to  claim 17 , wherein:
 the coefficients (A, B, C) serve for matching the respective temperature sensor elements and the transmitter unit, i.e. a first set of coefficients (A, B, C) for matching the first temperature sensor element and a second set of coefficients (A′, B′, C′) for matching the second temperature sensor element.   
     
     
         19 . A measuring device according to  claim 18 , wherein:
 the coefficients are ascertained during a calibration of the temperature sensor elements and are stored in the transmitter unit.   
     
     
         20 . A temperature head transmitter; wherein:
 the temperature head transmitter is a two conductor measuring device with two measurement inputs and an analog output;   the temperature head transmitter has a build-in transmitter unit,   the temperature head transmitter has a single the measuring transducer with a first and a second temperature sensor element,   the first temperature sensor element is connected to the first measurement input and the second temperature sensor element to the second measurement input of the temperature head transmitter; and   in the transmitter unit, the measuring signals of the two temperature sensor elements are be (pre-)processed and/or diagnostic functions using the measuring signals are executed.   
     
     
         21 . A temperature head transmitter according to  claim 20 , wherein:
 the temperature head transmitter detects a line break, a short circuit, and a corrosion, as well as a wiring error respectively.   
     
     
         22 . The temperature head transmitter according to  claim 20 , wherein:
 the working range of the measuring transducer and the ambient temperature is monitored by said transmitter unit.   
     
     
         23 . A temperature head transmitter according to  claim 20 , wherein:
 corrosion of said measuring transducer connection lines, which serve for the connecting said measuring transducer with said transmitter unit, are monitored, and in case the line resistances exceed plausible limits a corresponding error report can be output via the analog output.