SU130210A1 - Automatic refractometer - Google Patents

Description

Automatic refractometers are known which consist of a refractometric sensor with a tracking photometric system, a balanced electronic bridge with a pointer and vice versa: a connection with the sensor.

The proposed automatic refractometer, as compared with the known ones, provides an increased accuracy of reading indications when determining the concentration of dark and turbid solutions.

This is achieved by the fact that the following system of the refractometric sensor is made using a swinging mirror and the feedback between the electronic bridge and the sensor is carried out by selsins. In the follow system, a thermocompensation device consisting of a thermistor and a calibrated resistance is used.

FIG. 1 is a diagram of an automatic refractometer; pas figs. 2nd optical design; in fig. 3-circuit electric refractometer.

The refractometer sensor is a measuring sensor I, constantly washed by the test solution.

From the light source 2, the beam through the light filter 5 and the condenser 4 falls on the measuring prism Y, refracts onto two mirrors 5 and 6, and reflects from them, is directed to two photoresistances 7 and 8.

The photoresistors 7 and S are connected via an amplifier 9 of the type UZM239 to the electronic bridge circuit 10 of the type MCPI-06. The output of the bridge amplifier is connected to a reversible electric motor 11 of the type RD-09, which is; through a gearbox it is connected with selsyn 12 type BD-404a.

In the equilibrium state of the next system, the instrument system, the light-shade boundary, is projected onto the central part of the photoresistance unit 5. At the same time, the useful signal at the output of the amplifier is insufficient to drive the reversing electric motor.

A change in the concentration of the measured liquid displaces the boundary of the light and shadow, and the photoresistance unit 8 appears in the light or dark zone, i.e., more than 130210-2 gets into the photoresistance unit 8 or less than the light flux. The photoresistance unit 7 is constantly in the light zone of the light flux, and about half of its photosensitive surface is illuminated.

Depending on which part of the light flux falls on the photoresistance unit 8 (dark or bright field), the phase of the output voltage of the amplifier depends, which in turn determines the direction of rotation of the electric motor.

The sensor 9 is electrically connected to the selsyn receiver 3, which rotates a mirror 6 through a reducer reflecting the light and shade boundary.

The signal from the synchro sensor 12 is also supplied to the correspondingly calibrated synil pointer 13.

The second mirror 5 falls light, the intense part of the luminous flux falls, and the tracking system is brought into equilibrium according to the change in the concentration of the liquid to be measured.

The electronic bridge 10 is provided with an adjustment range adjuster by acting on the actuator 14 controlling the control valve 15 of the solution placed on the pipe 16 in which the measuring prism is mounted.

A thermocompensation device 17 is included in the photoresistance system, consisting of a KMT-I type thermistor, a calibrated resistance and resulting in a refractometer reading of 20 °.

Subject invention

Claims (2)

1. An automatic refractometer consisting of a refractometric sensor with a tracking photometric system, a balanced electronic bridge with a pointing device and feedback with a sensor, characterized in that, in order to increase the accuracy of indications in determining the concentration of dark and turbid solutions, the following system A refractometric sensor is made using a swinging mirror and the feedback between the electronic bridge and the sensor is made by selsyns. 2. Use in the follow system of an automatic refractometer according to claim 1 a temperature-compensating device consisting of a thermistor and a calibrated resistance. rm