SU382123A1 - WAY OF OBTAINING A RELATION OF TWO ANALOG - Google Patents

Description

one

The invention relates to methods for measuring the ratio of two analog quantities and can be used, in particular, to measure the ratio of the magnitude of two light fluxes in digital form when determining the seawater attenuation index (transparency).

In a known transducer, testing is performed by the engine that re-places the optical class-in. The mixing of the optical wedge is converted by a potentiometer into an electrical signal supplied to the control panel for registration.

This method of signal processing has a significant measurement error, especially in the initial part of the scale, and a low rate of signal processing. The circuit implementing this measurement method has significant drift. In the manufacture of the device, a large amount of mechanical work is performed, and the accuracy of machining of parts is required. The circuit does not have protection from external electric and magnetic fields.

The proposed method for obtaining the ratio of two analog signals is based on the conversion of signals into a digital code and consists of a predetermined digital value of a reference value with which the result of the conversion of the first analog is compared.

the signal, the obtained result of the comparison is converted into a control signal for converting the second analog signal into a digital form with the subsequent comparison of the conversion results and the ratios of the analog signals are determined from the comparison results.

The application of the proposed method achieves an increase in measurement accuracy, measurement and reading speeds. The ratio of two analog values, one of which is the reference (reference), and the other measured, is obtained on one counting device without calculation. Protection against the effects of external electric and magnetic fields is achieved by converting analog values into time intervals.

The proposed method of obtaining the ratio of two analog signals can be implemented, for example, in a photometer, the block diagram of which is shown in the drawing.

The photometer works as follows.

The optical design of the dual-beam instrument, with a single radiation source, a single photodetector, and a mechanical modulator. In the underwater part of the photometer, the reference and measurement light flows with time intervals between them through the optical system. To the photodetector /, the signal from which is converted in time.