Measurement of flow rate of powder from a hopper
US4730499A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1986 |
| Grant date | Mar 15, 1988 |
| Priority date | — |
| Expiry date | Nov 4, 2006 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01G11/003
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
In a system and a method for measuring the rate at which powdered material flows from a container wherein a first analog signal representing the weight of the container is produced, the analog signal is differentiated to obtain a second signal corresponding to the flow rate and the second signal is passed through an adaptive filter. The adaptive filter includes a first low pass filter having a first time constant for producing a third signal and a second low-pass filter to produce a fourth signal. The time constant of the second filter is varied between a minimum equal to the time constant of the first filter and a maximum equal to a preselected multiple of the time constant of the first filter by comparing the absolute value of the difference between the third and fourth signals to a preselected deadband and effecting the maximum time constant when the absolute value of the difference is less than the deadband and the minimum time constant when the absolute value of the difference is greater than the deadband. A combination signal is provided from the fourth signal during the time when the absolute value of the difference is less than the deadband and the third signal during the t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.