System and method for linearizing analog measurements during analog-to-digital conversion
US3979745A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1974 |
| Grant date | Sep 7, 1976 |
| Priority date | — |
| Expiry date | Feb 22, 1994 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03M1/60
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An instrument for linearizing a non-linear analog output produced from a sensor such as a thermocouple to obtain a true measurement of the parameter or engineering units of interests. The full range of the non-linear analog output is divided into segments and within each segment the second slope or the rate of change of the first slope of the analog output is predetermined and stored. In carrying out measurements, the magnitude of the analog output sensed is converted to constant frequency pulses. When measurements are carried out, within a given segment the corresponding second slope data is employed to modify the frequency of the constant frequency pulses to obtain output pulses for accumulation. These output pulses have a frequency which at any given moment is representative of the first slope of the analog output and which changes at a rate representative of the rate of change of the first slope of the analog output. The resulting output pulses thus are accumulated at a non-linear rate to obtain an output that will accurately follow the non-linear curve of the sensor and which will result in a true measurement of the engineering units of interest.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.