NORMALIZED PROCESS DYNAMICS
FIG11 is a graph of a target frequency response for a standard deviation of a differential pressure signal
At step 1002, a target standard deviation frequency response 918 is retrieved or computed by microprocessor 264. In accordance with one embodiment, the target frequency response is the standard deviation frequency response of a filtered sensor signal produced by a model sensor operating at a selected temperature and at the same range as the sensor in the field device and filtered by a high pass difference filter. An example of such a target frequency response is shown in FIG11 where frequency is shown along horizontal axis 1100 and the standard deviation of the filtered sensor signal produced by a model sensor at a selected temperature is shown on vertical axis 1102. In accordance with one embodiment, the selected temperature is room temperature. By constructing the filter so that the standard deviation frequency response matches the target frequency response of FIG11, it is possible to filter the sensor measurements taken at different temperatures so as to normalize the frequency response of the standard deviation across temperatures. This is accomplished by dynamically changing the filter as the temperature changes so that regardless of the sensor temperature, the same standard deviation frequency response is achieved.
graph
1100
shown along horizontal axis
2
transmitters range
4
uses EQ.
20
embodiment
6
EQ.
10
process plant
1102
vertical axis
['4. The computer readable medium of claim 3 wherein the target frequency response comprises a frequency response of a standard deviation of a filtered sensor signal wherein the sensor signal is produced by a model sensor operating at a same range as the sensor and at a selected temperature.']