Method for the conversion of a measured signal, a converter as well as a measurement setup and a pirani measuring circuit
US5475623A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 10, 1995 |
| Grant date | Dec 12, 1995 |
| Priority date | — |
| Expiry date | Feb 10, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01L21/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for convening a measured signal which, at least in a first approximation, is related to a quantity of interest by the equation (a): ##EQU1## where y is the quantity of interest, x is the measured signal, and k, k.sub.N, k.sub.Z are constants, into a signal that is a function of the quantity of interest. The method implements the function (b): EQU ln y=prop. ([ln (x-k.sub.N)-ln (k.sub.Z -x)]) wherein prop. means proportional, and where the function is implemented in an approximated manner by at least two bipolar transistors that have base emitter voltages that are dependent on collector currents of the bipolar transistors for receiving an output signal according to the equation (c): y'=ln y, with y' being the output signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.