Method to obtain a temperature compensated output signal in an optical current measuring sensor
AssigneeSiemens Aktiengesellschaft
InventorPETER MENKE
Life of this patent
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Abstract
In a magneto-optical sensor with −/+ intensity norming, the temperature-coefficient-compensated output signal (S) is obtained by formation of a quotient of the alternating portion (PAC) of the intensity-normed signal (P) and a function (f(PDC, PACeff)), determined by a calibration measurement, of a direct portion (PDC) of the intensity-normed signal (P) and of a root-mean-square value (PACeff) of the alternating portion (PAC). A corresponding method for sensors with AC/DC intensity norming is indicated.
Claims6
Method for obtaining a temperature-coefficient-compensated output signal (S) in an optical sensor (1) for measuring a periodically fluctuating electrical and/or magnetic field strength,
- in which sensor (1)
- light (L) that can be influenced by the field strength is sent through the periodically fluctuating field strength,
- from this light (L) that has been sent through and influenced, two intensity signals (L1, L2) are produced that are separate from one another and that comprise intensities (I1, I2) containing intensity portions that fluctuate in chronologically periodic fashion in phase opposition to one another dependent on the periodically fluctuating field strength, and
- a quantity (P) is derived from the two intensity signals (L1, L2), which quantity corresponds to a quotient of a difference (I1−I2) of the intensities (I1, I2) of the two intensity signals (L1, L2) and the sum (I1+I2) of these intensities (I1, I2), whereby
- the quantity (P) comprises a direct portion (PDC) and a periodically fluctuating alternating portion (PAC) with a root-mean-square value (PACeff),
- characterized in that
- the temperature-coefficient-compensated output signal (S) is obtained by formation of a quotient of the alternating portion (PAC) of the derived quantity (P) and a function (f(PDC, PACeff)), determined by a calibration measurement, of the direct portion (PDC) and of a root-mean-square value (PACeff) of the alternating portion (PAC) of the derived quantity (P)
Method for obtaining a temperature-coefficient-compensated output signal (S) in an optical sensor (1) for measuring a periodically fluctuating electrical and/or magnetic field strength,
- in which sensor (1)
- light (L) is sent through the periodically fluctuating field strength,
- from this light (L) that has been sent through, two intensity signals (L1, L2) are produced comprising intensities (I1, I2) that contain alternating portions (AC1 [sic], IAC2) that fluctuate periodically in phase opposition to one another dependent on the periodically fluctuating field strength and that contain a respective direct portion (DC1, IDC2), and
- a respective normed quantity (S1, S2) is derived from each of the two intensity signals (L1, L2), which normed quantity corresponds to a quotient of the alternating portion (AC1, IAC2) and the direct portion (DC1, IDC2) of the intensity (I1, I2) of this intensity signal (L1, L2), characterized in that from the two derived quantities (S1, S2)
- a first quotient (P′DC) is derived from the sum (S1+S2) and a difference (S2−S1) of the two normed quantities (S1, S2), and
- a periodically fluctuating second quotient (P′AC) is derived from the twofold product (2S1S2) and the difference (S2−S1) of the two normed quantities (S1, S2), and in that
- the temperature-coefficient-compensated output signal (S′) is obtained
- by formation of a quotient of the periodically fluctuating second quotient (P′AC) and a function (f(P′DC, P′ACeff)), determined by a calibration measurement, of the first quotient (PDC) and of a root-mean-square value (P′ACeff) of the periodically fluctuating second quotient (P′AC).
Dependencies are inferred from the claim text.