SU1246724A1 - Optical gas analyzer - Google Patents

Description

ten

15

124672A

The invention relates to analytical instrumentation and can be used to control emissions of romplennyh enterprises and vehicles into the atmosphere, as well as for control of technological processes associated with the release of gaseous gas of 1H.

The purpose of the invention is to increase the measurement accuracy.

The drawing shows the structure of an optical gas analyzer circuit.

The gas analyzer contains an optical part 1, which includes a source of study with a reflector, a working and porous cuvette, a focusing system, a bird filter and a rotating mirror, a modulator 2 with cutouts for generating synchronizing pulses, an synchronizer 3 of synchronizing pulses, made as a U-shaped holder fixed in it by a photodiode and a light bulb (not shown in the drawing), located opposite the modulator cutouts, and mounted for movement along the radius of rotation of the modulator, successively connect The first radiation receiver 4, the preamplifier 5, the synchronous filter 6, the main amplifier 7, the synchronous detector 8 and the recording device 9, the driver 10 of control signals, the input of which is connected to the output of the driver of the three synchronizing pulses, and the code are connected to the control inputs synchronous filter 6 and synchronous detector 8, as well as a phase meter I, measuring the phase difference of the signals at its inputs, connected to the outputs of the preamplifier 5 and the formatter 10 of the control signals, and the motor 12, connect nny to the output of the phase meter 11 and moves the mechanically associated therewith n-ny The samples holder along the radius of rotation of the modulator 2 ..

The device works as follows.

Radiation from a source located in the optical part I of the optical analyzer is divided into two streams that pass through the working and reference cells, modulated by modulator 2 and focused onto the receiving area of the receiver 4, which is converted into electr hus up to cher

20 fi va pa no

25 on si

si on

30 more

xp

35 those on si li k on c x

50 y

40

45

55

five

After that, the signal is amplified by preamplifier 5 and fed to the input of synchronous filter 6 and to one of the inputs of phase meter II. Synchronously, with interruption of radiation fluxes. Passing through the working and reference cells, the radiation flow is interrupted, going from the light bulb to the photodiode located in the U-shaped holder of the synchronization pulse generator 3, as a result of which a pulse sequence is formed at the output of the synchronization pulse generator 3, the repetition frequency of which is equal to the frequency of the module radiation fluxes passing through the working and supporting cells.

From the output of the synchronous filter, the filtered useful signal is amplified by the main amplifier 7 and retreats to the input of the synchronous detector 8, in which a half-period rectification of the useful signal is synchronous with the control voltage.

A constant output voltage of the synchronous detector 8, proportional to the concentration of the measured substance in the working cell, is monitored by means of a recording device 9.

Control voltages for syn. Chronic filter 6 and synchronous detector 8 are the output voltages of the control signal generator Sh, designed to create synchronous and in-phase control signal generator with the output signals of the control voltage generator 3 with the required polarity and amplitude. The same output voltage is applied to the second input of the phase meter It, which measures the phase difference of the applied voltage to its voltage inputs, and in case of their mismatch produces at the output the error signal that controls the engine 12, which, depending on the field rnity

50 of the control signal shifts the U-shaped holder along the cutouts to generate synchronizing pulses along the rotation radius of the modulator until the error signal becomes equal to, i.e. the output signals of the preamplifier 5 and the control signal driver / coincide in phase. Thus,

0

45

55

3 12467244

There is a compensation for the difference in phasic destabilizing factors between the control voltage and can reach 40-50 °. With phase

Useful input signal. 90 ° shift

Increasing the accuracy of measurements of a dos-optical gas analyzer is completely repetitive by increasing the sensitivity-s disappears, and with linear dependency by eliminating the automatic value of the useful

tracking phase shift phase shift with an average possible between the modulated useful value of the phase shift, parisignal and output with gnatsomomirovomom about 45, the control signal sensor and its Optical Gas Analyzer

compensation because the phase difference between. will be 2 times higher than that of the gas analyzer

these signals under the influence of the gap without phase compensation.

Compiled by A.Levi

Editor A.Kupr ková Techred O.Gortvai Corrector E. Roshko

Order 2571 Circulation 412. Subscription

VINILI State Committee of the USSR

for inventions and discoveries 113035, Moscow, F-33, Raushsk nab., d, 4/5

Production and printing company, Uzhgorod, st. Lrnestna 4

Claims (1)

An OPTICAL GAS ANALYZER containing an optical part, a cut-out modulator, equipped with a clock driver and coupled to a control signal driver, and a measurement circuit including a series-connected radiation receiver, a pre-amplifier, a synchronous filter, a main amplifier, a synchronous detector and a recording device, while the output of the driver of the control signals is connected to the control inputs of the synchronous filter and synchronous detector, with the exception of the fact that, in order to increase To ensure measurement accuracy, it additionally contains a phaeometer and an engine, and the clock generator is made in the form of a shaped holder with a photodiode and a lamp fixed in it, located opposite the cutouts of the modulator, and mounted with the ability to move along the radius of rotation of the modulator, with the first and second inputs the phase meter is connected to the outputs of the pre-amplifier and driver of the control signals, respectively, and the output is connected to the engine, which is mechanically connected to the U-shaped holder. W)