摘要:
The Bragg grating device for measuring an acceleration, has at least two optical Bragg gratings (11, 12), each formed in elastic material, for supplying optical radiation (S) and at least one deflectable mass (M) connected to both gratings for generating an inertial force that is dependent on the acceleration which acts upon the device, in order to produce elastic extension of one of the two gratings and simultaneous elastic contraction of the other grating. The device is also suitable for vibration frequency measurement.
摘要:
The method and the device are used for compensating for interfering variables in an optical sensor (50), which is at least sensitive with respect to a measured variable (M), a wavelength (λ) of the optical signal (S1) fed in and an interfering variable (T). The optical signal (S1) also passes through a compensation element (40) which, together with the optical sensor (50), is located in a common interfering variable effect range (60) with the same effect of the interfering variable (T). In the compensation element (40), the interfering variable (T) changes the wavelength of the optical signal (S1) in such a way that the partial influences that take place in the optical sensor (50) on account of the changed wavelength and on account of the interfering variable (T) cancel one another out.
摘要:
A method and a device for imaging an object using ultrasound. Transducer elements of a two-dimensional array are interconnected to form sub-arrays. The transducer elements of each sub-array are driven in the transmit mode with the same time delay and read out jointly in the receive mode. In this manner, the number of required time delays is reduced, and parasitic capacitances on the signal lines are diminished.
摘要:
An ultrasonic transducer array in which distances between the array's transducer elements (T.sub.ij) increase in the direction of the rows (x direction) and in the direction of the columns (y direction) from a center of symmetry (S) outward. The integral over a straight-line function f(x) and/or g(y), which steeply decreases on either side of a center of symmetry (S) between the center points (M.sub.ij) of adjacent transducer elements (T.sub.ij), is constant for each row and/or column. Thus, the number of transducer elements (T.sub.ij) is reduced without considerable deterioration of the beam characteristic of the transducer array.