Temperature prediction transmitter
View Patent ↗A system and method is provided for predicting a physical quality such as temperature, the measurement of which tends to be hindered by a time-related impediment. A single sensor is configured to detect, in real time, the physical quality Q detect , and one or more infinite impulse response filters are configured with time constants correlated to the time-related impediment. The infinite impulse filter(a) are configured to filter Q detect to output a filtered quality measurement (Q filtered ). A processor is configured to calculate, in real time, the estimated or predicted quality Q estimate using Q detect and Q filtered .
1. A method for transforming physical quality data into an estimated measured quality, comprising:
a) obtaining, with a sensor in real time, data representing a physical quality (Q detect ), wherein an impediment exists to the detection of the physical quality;
b) filtering Q detect through a first IIR filter (IIR 1 ), wherein the IIR 1 outputs Q filtered1 ;
c) calculating, with a processor in real time, the estimated measured quality (Q estimate ) using Q filtered1 and Q detect ;
d) filtering Q filtered1 through another infinite impulse response filter configured to output another filtered quality measurement (Q filtered2 ); and
wherein said calculating (c) includes calculating the estimated quality Q estimate using Q filtered1 and Q filtered2 .
2. The method of claim 1 , wherein said obtaining (a) comprises obtaining, with a temperature sensor, data representing a physical quality (Q detect ) in the form of temperature, wherein the impediment comprises a barrier disposed between the temperature sensor and the material; and said filtering (b) and calculating (c) is effected by a temperature compensation transmitter.
3. The method of claim 2 , wherein the material comprises a process fluid and the barrier comprises a casing disposed about the temperature sensor, wherein the casing is configured for extension into process fluid flow.
4. The method of claim 3 , further comprising:
e) disposing the temperature sensor within the casing; and
f) inserting the casing into the process fluid flow.
5. The method of claim 1 , wherein said calculating (c) comprises calculating, with the processor, Q estimate by subtracting the value of Q filtered2 from twice the value of Q filtered .
6. The method of claim 1 , wherein said calculating (c) comprises calculating, with the processor, Q estimate by calculating the difference between Q filtered1 and Q filtered2 , and adding the difference to Q filtered1 .
7. The method of claim 1 , comprising configuring the infinite impulse response filter to employ a first time constant (τ 1 ) correlated to the time-related impediment.
8. The method of claim 7 , comprising configuring the other infinite impulse response filter to employ a second time constant (τ 2 ) correlated to the time-related impediment.
9. The method of claim 1 , comprising:
filtering Q filtered1 through an additional infinite impulse response filter configured to output an additional filtered quality measurement (Q filteredadd ); and
wherein said calculating (c) includes calculating the estimated quality Q estimate using Q filtered1 , Q filtered2 and Q filteredadd .
10. The method of claim 9 , wherein said processor is configured to calculate the estimated quality Q estimate using the formula Q estimate =Q filtered1 =Q filtered1 +(Q filtered1 −Q filtered2 )+(Q filtered1 −Q filteredadd ).
11. The method of claim 1 , comprising recording, with the processor, a plurality of data points of Q detect over time.
12. The method of claim 11 , comprising determining, with the processor, in real time, the slope of Q detect at the plurality of data points.
13. The method of claim 12 , wherein said calculating (c) comprises determining Q estimate using the slope of Q detect detected at the plurality of data points.
14. The method of claim 13 , wherein said calculating (c) comprises calculating with the processor in real time, a final value for Q estimate , denoted as Q estimatefinal , by the formula Q estimatefinal =Slope Q detect ×K)+(Q estimate ) wherein K is a constant having a value correlated to the time-related impediment.