Digital filter for random variable
US5003502A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 25, 1988 |
| Grant date | Mar 26, 1991 |
| Priority date | — |
| Expiry date | Oct 25, 2008 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N9/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A digital filter for use with a randomly generated variable, such as in a radioactive densometer, is provided and includes a microprocessor and timing clock for sampling the random variable over a specific time interval. The microprocessor utilizes a weighting factor based upon a first confidence factor and computes the mean value of a first sample of the random variable and compares the number of standard deviations that a subsequent sample is from the mean value of the previous sample and uses a probability related factor to determine if the subsequent sample represents an actual change in density. Further, the microprocessor uses a second confidence factor in determining the weighting factor which counts the number of consecutive times that the subsequent samples are greater than, or less than the mean value and again determines a probability related factor to determine if a change in density is actually occurring. As both the first and second confidence factors increase, so does the weighting factor and the probability that an actual change in fluid density has occurred.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.