CN104502714B

CN104502714B - Electrode rotating type liquid conductivity measuring method

Info

Publication number: CN104502714B
Application number: CN201410827061.5A
Authority: CN
Inventors: 廖晓东; 洪亲; 林宏心
Original assignee: Fujian Normal University
Current assignee: Fujian Normal University
Priority date: 2014-12-26
Filing date: 2014-12-26
Publication date: 2017-05-17
Anticipated expiration: 2034-12-26
Also published as: CN104502714A

Abstract

The invention discloses an electrode rotating type liquid conductivity measuring method. By adopting a miniature motor, tested liquid can quickly and cyclically run through a gap between electrode claws of two electrode terminals in the circumference direction, and the electrode claws of the electrode terminals can be scoured, so that ions cannot be accumulated and attached to the surface of measuring electrodes, and a stable double electrode layer is formed. Polarization of the electrodes is avoided, and by adopting direct-current voltage for excitation, methods for testing and computing are simple and reliable, the effects of distribution capacitance between the electrodes and the leads of the electrodes can be ignored and interference resistance is high.

Description

A kind of electrode rotary formula liquid electric conductivity measuring method

Technical field

The technical program is related to the measuring method of liquid electric conductivity or resistivity, more particularly to electrode polarization can be completely eliminated And using the liquid electric conductivity or method of measuring resistivity of continuous current excitation.

Background technology

The measurement of liquid electric conductivity is widely used in the numerous areas such as industrial production, water quality monitoring.Electrical conductivity of solution Fundamental method of measurement is the voltage U that measurement is applied on the two ends of the electrode for the inserting solution and electric current I for flowing through electrode, calculates electricity Resistance R=U/I between pole, with G=K/R the electrical conductivity of solution is calculated, and wherein K is electrode constant.But the electrode inserted in solution Polarization can be produced after powered up, makes the voltage U for measuring not be substantially the voltage at solution two ends itself, and be consequently exerted at solution electricity Voltage on resistance series connection electrode polarization two virtual electronic devices of equivalent capacity, therefore there is theoretical error in formula R=U/I；In order to Reduce impact of the electrode polarization to accuracy of measurement, conventional method is to apply the symmetrical alternating current of positive-negative polarity on electrode such as Sine wave enters row energization, but ac-excited method can simply reduce electrode polarization impact, and electrode polarization can not be completely eliminated Impact, and ac-excited electrode interelectrode capacity and the contact conductor electric capacity of introducing is to the adverse effect that measures.

The content of the invention

The purpose of the technical program is to provide and a kind of electrode polarization is completely eliminated and using the liquid electric of continuous current excitation Conductance measuring method.

Realizing the technical scheme of above-mentioned purpose is：A kind of electrode rotary formula liquid electric conductivity measuring method, comprising following step Suddenly：1st, the electrode pawl of measuring electrode is placed in the conductance cell for holding fluid to be measured；2nd, starting micromachine revolves measuring electrode Rotate into and make fluid to be measured Rapid Circulation circumferential through the gap the electrode pawl of two electrode tips；3rd, applied by two slip rings Plus constant direct energizing voltages；4th, with the DC current of ammeter measurement stream Jing fluid to be measured；5th, with reference to the electricity of measuring electrode Pole constant calculations electrical conductivity；

Measuring circuit is connected as：The stator of two slip rings is connected to constant pressure source and ammeter, the electricity of composition by cord Flowing loop is：Positive pole -- the first slip ring -- second electrode end -- fluid to be measured -- first electrode end -- of constant pressure source Fixing screws -- the output shaft of micromachine -- the second slip ring -- positive pole of ammeter -- negative pole of ammeter -- The positive pole of the negative pole of constant pressure source -- constant pressure source.

The innovative point of the technical program is：Micromachine makes fluid to be measured circulation quickly pass through two electricity with circumferencial direction Gap between extreme electrode pawl, to the electrode claw type of two electrode tips into souring, therefore measuring electrode surface can not Aggregation and adhere to ion forming firm electric double layer, it is to avoid electrode polarization, swashed using the easy DC voltage realized Encourage, the impact without the need for considering the distribution capacity between electrode interpolar and contact conductor, anti-interference is extremely strong.

Description of the drawings

Fig. 1 is the hardware system schematic diagram involved by the technical scheme of the application.

Fig. 2 is the top view of the electrode terminal involved by the technical scheme of the application.

Specific embodiment

The technical scheme of the application is further described below in conjunction with the accompanying drawings：

In Fig. 1, two electrode tips of 1 and 2 expression measuring electrodes, referred to as first electrode end 1 and second electrode end 2, two Electrode tip is flat cylindrical straight barrel shape, and second electrode end 2 is enclosed within outside first electrode end 1, and two electrode tips keep same Axle, between the cylindrical side wall of two electrode tips appropriate gap is left, as shown in Fig. 2 the cylinder of the straight tube in two electrode tips Equally spaced several gap for being provided with equal number, form identical number on the wall of shape side on the cylindrical side wall for making two electrode tips Several electrode pawls of amount；Such as Fig. 1, at the flat center of two electrode tips screw mounting hole is provided with；Two pads are first Pad 4, the second pad 6 are electric insulations, and are provided with screw mounting hole in the centre of two pads；Two slip rings are One slip ring 5 and the second slip ring 7 are constituted by rotor and stator, and the inner ring of slip ring is rotor, and the outer shroud of slip ring is stator, exterior ring cap It is mounted on outside inner ring, inner ring and outer rings can be carried out relatively slipping in the circumferential direction and keep electrical contact, and at the center of inner ring spiral shell is provided with Nail installing hole；The output shaft of micromachine 8 is provided with the screw hole supporting with fixing screws 3 in axial location；Fixing screws 3 are passed through The flat of first electrode end 1, the first pad 4, the flat of second electrode end 2, the first slip ring 5, the second pad 6, the second slip ring 7 this A little screw mounting holes for being sequentially close to part or position mutually, the screw hole for screwing in and being fixed on the output shaft of micromachine 8； First electrode end 1 is sequentially electrically connected by fixing screws 3, the output shaft of micromachine 8 with the second slip ring 7；Fixing screws 3 With the first slip ring 5 without Mechanical Contact；It is close to that there is electrical connection with the machinery of the first slip ring 5 in second electrode end 2；On two electrode tips The one-to-one radial direction of electrode pawl honest face.

Circuit is connected as：The stator of two slip rings is connected to constant pressure source E and electric current Table A, the electric current of composition by cord Loop is：Positive pole -- the first slip ring 5 -- -- fluid to be measured -- first electrode end 1-of second electrode end 2 of constant pressure source E - fixing screws 3 -- output shaft of micromachine 8 -- the second slip ring 7 -- positive pole of electric current Table A -- electric current Table A it is negative Pole -- negative pole of the constant pressure source E -- positive pole of constant pressure source E.

Measurement liquid electric conductivity the step of be：The 1st, the electrode pawl of measuring electrode is placed in the conductance cell for holding fluid to be measured In；2nd, starting micromachine 8 makes measuring electrode rotation and then makes fluid to be measured Rapid Circulation circumferentially through two electrode tips 1 and 2 Electrode pawl between gap；3rd, it is constant pressure source E to apply constant direct energizing voltages by two slip rings；4th, ammeter A is used Measurement flows through the DC current of fluid to be measured；5th, electrical conductivity is calculated with reference to the electrode constant of measuring electrode.

Claims

1. a kind of electrode rotary formula liquid electric conductivity measuring method, it is characterised in that comprise the steps of：1st, by measuring electrode Electrode pawl is placed in the conductance cell for holding fluid to be measured；2nd, starting micromachine makes measuring electrode rotation and then makes fluid to be measured fast Speed circulation is circumferential through the gap the electrode pawl of two electrode tips；3rd, constant continuous current excitation electricity is applied by two slip rings Pressure；4th, with the DC current of ammeter measurement stream Jing fluid to be measured；5th, electrical conductivity is calculated with reference to the electrode constant of measuring electrode；

Measuring circuit is connected as：The stator of two slip rings is connected to constant pressure source and ammeter, the electric current loop of composition by cord Lu Wei：-- -- -- fluid to be measured -- first electrode end -- is fixed at second electrode end for the first slip ring for the positive pole of constant pressure source Screw -- the output shaft of micromachine -- the second slip ring -- positive pole of ammeter -- negative pole of ammeter -- constant pressure The positive pole of the negative pole in source -- constant pressure source.