SU954877A2 - Systems for measuring and programming eluent speed in chromatography - Google Patents

Description

one

The invention relates to chromatography and can be used in the analysis of mixtures of substances of complex composition using the programming of column temperature and / or programming of the flow rate of eluent.

According to the main auth. ff 842571 a system for measuring and programming the eluent rate is known. This system, which contains the Marker shaper installed in a calibrated channel, two indicators and a recorder, as well as a generator, two control triggers, five shift registers and a correlator. The label shaper is made in the form of a wire connected to the current pulse generator and the corrector, the first indicator is connected to the installation input of the unit of the first trigger, the output of which is connected to the first and second correlator inputs through the first, second and third correlator, the second indicator through

the switch is connected to the installation input of the unit of the second trigger connected by the output to the third input of the correlator. as well as through the fourth shift register — with the fourth input of the correlator; the input of the zero setting of the first trigger is connected to the output of the first shift register, and the output of the zero setting of the second trigger is connected to the output of the fifth register

10 shift, the length of the third register is equal to the length of the fourth, the sum of the lengths of the fourth and n registers is equal to the length of the first, shift register, and the shift inputs of all registers are connected to the height of the correlator L.

Since, in the known system, the measuring transducer and the electronic unit form a closed circuit, it is impossible to determine the source of the error and make corrections for purposes of higher than 1 accuracy.

The purpose of the invention is to improve the accuracy of measurement of the eluent velocity.

This goal is achieved by introducing a reference pulse generator into the system, and an additional shift register connected by its input to the input of the first shift register, and the output via the switch setting input of the second trigger unit, and the additional register shift inputs are connected to the reference pulse generator and the first input is with the comparison circuit, the second input of which is connected to the output of the correlator, and the output of the comparison circuit is connected to the corrective input of the correlator,

The drawing shows a diagram of the proposed system.

The system consists of a tube 1, in which a calibrator of the label 2 and sensible terminals 3 and || are installed in a calibrated channel, which serve as indicators. The label 2 former is connected to the generator 5 current pulses. The trigger 6 is connected to the installation of the unit with the indicator 3, and the input of the installation of the zero with-output register .7 shift. The output of the trigger 6 through the shift registers 7.8 and 9 is connected to the first and second, eye inputs of the correlator 10. The indicator k is connected to the installation input of the trigger unit t2 through the switch 11, the output of which is connected to the installation input zero of the trigger 13 via the shift register 13 12. The third and fourth inputs of the correlator 10 are connected to the outputs of trigger 12 and the shift register 13. The input of registers 15 and 7 is combined, and the output of register 15 is connected through switch 11 to a trigger 12. The shift input of register 15 is connected to a reference generator 16, for example, a quartz and the first one frequency comparison circuit 17 house. The second input of the comparison circuit 17 is connected to the output of the correlator 10, and the output is connected to the corrective input of the correlator 10.

The principle of the system is as follows.

The eluent, whose rate is determined, flows through the tube 1, in the calibrated channel of which the heating eluent 2 and two sensitive elements 3 and are installed in series. Element 2 from generator 5 is supplied with current pulses, and temperature labels are produced in the output of which in the flow, being carried by the flow towards the sensitive elements VI k. When the temperature mark of element 3 is reached, the trigger 6 is set to state one

This information enters the sequential-included registers 7-9 of the Shift. After the delay of the shift register 7, a single information appears at the input of the zero setting of the trigger

6, returning it to its original state. Thus, a pulse is formed, the duration of which is proportional to the length of register 7 and the period of the clock pulses at the shift inputs. Further, this impulse is delayed by registers 8 and 9. From the output of register 8, this pulse arrives at the input .1 of the correlator 10, and from the output of the register 9 to the input 11 of the correlator 10..

In the moment. the temperature mark of the indicator k is reached and provided that the switch 11 is in the position And

(measurement), trigger 12 is set to state one; information from the output of this trigger 12 enters the input of the shift registers 13 and 14. From the output of the register lA, the unit enters the information at the input of the zero setting of the trigger 12 and returns this trigger 12 to the original COC-. that notion. The pulse duration, formed by trigger 12, is equal to the pulse width, generated by trigger-.

Hommer 6. With the release of registers 13 and I

the information is fed to the inputs of the SRI 1U correlator 10. The duration of the pulses applied to the inputs of the correlator 10 is the same (due to the equality of the register 7 to the sum of the registers 13 and 1). The task of the correlator 10 includes finding the time coordinate of the mutual correlation function impulses arriving at the inputs

1 and P with pulses arriving at inputs III and 1U, and changing the frequency of the pulses that are fed to the shift inputs of registers 7.8; 9.13 and. Output frequency following

The pulse correlator of the torp 10 is changed so that the delay introduced by registers 7 and 8 becomes equal to the transport delay of the temperature label associated with the gas flow and the distance between the sensitive elements 3 and 4. Thus, the output frequency will be proportional to the gas velocity, i.e. expense.

in control mode, switch 11 is set to position K. The pulses arriving at the input of register 15 are delayed and are fed through switch 11 to the input of the installation of the trigger unit 12. The length of the delay register 15 is equal to the sum of the lengths of the registers 7 and 8. The clock pulses at the shift input of the register 15 come from the output of the reference generator 16. As the length register 15 is equal to the sum of the lengths of registers 7 and 8, the frequency at the shift inputs of registers 7,8,9,13 and T must be equal to the reference frequency of the generator, 16. These frequencies are compared with device 17, and in case of imbalance, the corrective input of the correlator 10 is applied to the control setting / output frequency of the correlator 10. Thus, the system is periodically adjusted by the reference generator 16, for example, quartz.

The economic efficiency of the proposed system for measuring and programming the eluent rate is due to an increase in the accuracy of chromatographic analysis, which is most important when using a chromatograph in systems of automatic control of the technological process.

Claims (1)

Invention Formula The system for measuring and programming the eluent rate in chromatography according to ed. St. IP 842571 with the fact that, in order to improve the measurement accuracy, a reference pulse generator, cos, and an additional T) shift register, connected by its input with the input of the first shift register, was entered into it, and the output through the switch — to the installation input of the unit of the second trigger; the shift inputs of the additional register are connected to the reference impulse generator and the first input to the comparison circuit, the second input of which is connected to the correlator output, and the B1 input of the comparison circuit is connected to the correction input corr l torus. . Information sources, taken into account in the examination t .. USSR Author's Certificate No. 8li2571, cl. G 01 N 31/08, 1979 prototype) ..