the adder 6 which is constituted by a simple junction the signal v 39 1 is clearly of the form the multiple linear circuit 4 transforms the voltage signal v 1 which is applied at its input and from there to the terminals a b c into current signals in the resistors r a r b r c namely i 39 1 v 1 r a i 39 2 v 1 r b i 39 3 v 1 r c the intensities i 39 1 i 39 2 i 39 3 are added to the constant intensities i 1 i 2 i 3 supplied by the resistors r 1 r 2 r 3 supplied by the voltage v 5 equ4 to within a multiplying coefficient r a r b r c the signals x y z linear as a function of v 1 are of the form the combining circuit 5 is constituted by a multiplier m 1 which effects the combination of the magnitudes x y z according to the general formula x sup u03b1 u00b7 y u03b2 u00b7 z sup u03b3 in which signals v 39 1 and v 34 1 are applied to the adder 6 constituted by a junction in this way the signal obtained is equ7 this signal is applied to the operational amplifier op 1 which gives the output the signal v 3 according to the formula indicated above in general by selecting the connections or by cutting one or other of the connections of the points a b c d the formula is adapted to the response curve of the transducer general equation 2 does not assume that.