CN1022950C

CN1022950C - Tester fo moisture content in rosin

Info

Publication number: CN1022950C
Application number: CN 91102545
Authority: CN
Inventors: 龚少楠
Original assignee: Individual
Current assignee: Individual
Priority date: 1991-03-29
Filing date: 1991-03-29
Publication date: 1993-12-01
Anticipated expiration: 2006-03-29
Also published as: CN1065528A

Abstract

The present invention discloses a measuring apparatus for moisture content in rosin, which is composed of a sample capacitance box, a coaxial cable, sampling circuit, a standard circuit, a triggering circuit, a comparison circuit, a time delay display circuit and a power supply circuit. A variable of electrical parameters caused by different moisture contents in the rosin is compared with an electrical parameter of the rosin with a known moisture content, and thus, the moisture content of the measured rosin is determined. The measuring apparatus has the advantages of simple operation, fastness, accuracy, light dead weight, portability and no limitation of environment and use conditions. The present invention can be widely used for rural and field purchase job sites with a large batch of rosin samples.

Description

Tester fo moisture content in rosin

The invention belongs to the physical quantity technical field, relate in particular to a kind of tester of moisture content in rosin.

From forest zone purchase rosin, for preventing turpentine oil volatile, the peasant will add water in rosin, because water mixing is random, the watering quantity of different vessels differs greatly, and the water content in the general rosin is between 5%～20%.

The measuring method of known fo moisture content in rosin and device adopt the way of distillation.The moisture rosin that takes a morsel is weighed the back with the terebinthina dilution, puts into distiller, distills out moisture content, claims the weight of moisture content again, divided by the former weight of rosin, draws the content of moisture content with moisture content weight.This known measuring method and device significant disadvantages are that the time of usefulness is long, and surveying once needs 30～60 minutes.

Another shortcoming of this known measuring method and device need be not easy in the rural area with heavy experimental facilities such as a large amount of terebinthina and electric furnace, Libra, distiller, open-air purchase is on-the-spot uses.

The objective of the invention is for avoiding these shortcomings and difficulty, provide a kind of light, be easy to carry about with one, be suitable for the on-the-spot tester fo moisture content in rosin that use, that can measure water content in the rosin rapidly and accurately of the open-air purchase in rural area.

Task of the present invention is achieved in that owing to the different variable quantities that cause electrical quantity of water cut in the rosin to be measured, compares with the variable quantity of the electrical quantity of the rosin of this variable quantity and a known moisture content, when balance, two values are equal.Design concept: for capacitor, the electric capacity between two parallel plate electrodes

C∝ε _rε· (S)/(d)

ε wherein _oBe permittivity of vacuum, ε _rFor relative dielectric constant, S are that the area d of pole plate is the distance between two-plate.

If between the electric capacity two-plate be the rosin that contains moisture content, if the water cut difference, according to the ε of above-mentioned relation formula correspondence _rAlso different with the value of C.Find out C and ε by prior experiment _rAnd the corresponding relation between the water cut has been measured electric capacity C and just can have been known the water cut of rosin, thereby realized that non electrical quantity is converted to the measurement of electric parameter, and in other words, fo moisture content in rosin can be determined by the amount of measuring capacitor C.

The measurement of capacitor C can be tried to achieve by the time constant that compares two circuit, promptly

If U _S=RC (dU(t))/(dt)+U _S(t)

U wherein _SBe voltage source, RC=τ be time constant (when the RC value not simultaneously, τ is also different), U _CBeing the voltage at electric capacity two ends, (t) is the unit interval.

For R _A, CA, τ _A=R _AC _A

For R _B, C _B, τ _B=R _BC _B

If τ _A=τ _B, C then _A=(R _B)/(R _A) C _B

If C _BKnown, (R _B)/(R _A) known, then can obtain C _A

Take following technical solution according to above-mentioned design concept:

A sample electric capacity box, its equivalent capacity and a resistance are in series, and form the RC circuit that a time constant equals τ, insert voltage source, obtain sending into sample circuit at the electric capacity two ends by the sawtooth pulse that index law changes, square-wave pulse of sample circuit output, its pulsewidth is determined by τ; A known τ basic pulse generator is exported a τ standard square-wave pulse, and its pulsewidth scalable is selected; A trigger, the output trigger pulse is sent into described sample circuit and described τ basic pulse generator simultaneously, triggers this two circuit synchronous workings; A comparer, the square-wave pulse that described sample circuit and described τ basic pulse generator are sent here carries out peak pulse duration, and comparative result is delivered to display; A described display shows comparative result after by a chronotron control lag a period of time; A direct-flow voltage regulation source is used for to described sample circuit, τ basic pulse generator, trigger, comparer, chronotron, monitor power supply.

The water cut that use the present invention measures rosin is without any additives, and is easy to operate, rapid and simple, surveys once and only needs 1 minute, and work efficiency improves 30～60 times than the way of distillation; The accuracy height, measuring accuracy can reach 0.1%, because it is many to extract the sample total amount of measuring, thereby more can represent whole sample; Cost is low, and about 200 yuan of every cost need be with heavy, expensive experimental equipment; In light weight, the 2kg/ platform is easy to carry, and not limited by environment and service condition, and the field purchase that can be widely used in sample in enormous quantities is on-the-spot.

Fig. 1 is the configuration diagram of fo moisture content in rosin measuring instrument.

Fig. 2 is the configuration diagram of A type sample electric capacity box.

Fig. 3 is the axonometric drawing of capacitor plate.

Fig. 4 is the configuration diagram of Type B sample electric capacity box.

Fig. 5 is the axonometric drawing of capacitor plate.

Fig. 6 is the measuring principle block scheme.

Fig. 7 is the metering circuit schematic diagram.

Describe the embodiment that the present invention provides in detail below in conjunction with accompanying drawing.

Fig. 1 illustrates the structure of fo moisture content in rosin measuring instrument of the present invention.Socket [1], pilot lamp [4], adjusting knob [5], power switch [8] are installed on the front plate of housing [7], printed circuit board (PCB) [2], battery case [6] are installed on the intraperitoneal of housing [7], concentric cable [10] is used to connect sample electric capacity box [9] and socket [1], front end leaves window [3] above the housing, so that observed reading.

In Fig. 2, Fig. 3, sample electric capacity box [9] is made with the little insulating material of dielectric loss, cover mouth above the box body, sandwich the capacitor plate [9-2] of conducting metal thin plate between parallel symmetrical fitting insulating panels in box body both sides [9-1] and the insulcrete [9-3], at limit end extraction electrode [9-4] and electrode [9-5], the surrounding sealing, pole plate [9-2] can be made various plane geometric shapes, but essential its area that guarantees is at 1cm ²～1000cm ²Between, the distance between the two-plate is between 1cm～15cm.

Sample electric capacity box [9] also can be made the such structure of Fig. 4.Cover mouth above the box body, in the box body chamber, installing a capacitor plate [9-7] that between insulcrete [9-6] and insulcrete [9-8], sandwiches the conducting metal thin plate as shown in Figure 5 on the basis of Fig. 2 additional, limit end extraction electrode [9-10], with the conductor extraction electrode [9-9] that is connected, this structure can increase volume and electric capacity to the pole plate of both sides at the limit end.

Fig. 6 is the measuring principle block scheme.Sample electric capacity box [9] is used for splendid attire sample to be tested, the shielding of added metal box among the figure, prevents external electromagnetic interference.Sample electric capacity box [9] is by concentric cable [10] and resistance R ₁The access voltage source is in series, form the RC circuit that a time constant equals τ, the output terminal of sample electric capacity box [9] inserts the input end [RC] of sample circuit [11], produce one at this input end and press the sawtooth pulse that index law changes, this signal enters sample circuit [11], will export the negative pulse square wave of a pulsewidth by the RC decision at its output terminal [Q]; τ basic pulse generator [12] is used to produce a known τ standard by output terminal [Q] output negative pulse square wave, and its pulsewidth can be regulated selected; Trigger [14] produces [B] end that a narrow negative pulse is delivered to sampling electricity [11] and τ basic pulse generator simultaneously, to trigger this two circuit synchronous workings; Comparer [13] carries out peak pulse duration to the losing side wave impulse that sample circuit [11] and τ basic pulse generator [12] are sent here, comparative result by its output terminal [Q], [Q] deliver to display [15] respectively, [16] show; Chronotron [17] is used to control display [15], [16] and postpones a period of time and treat that sample just works after stable; Direct-flow voltage regulation source [18] is used for providing working power to foregoing circuit.

Fig. 7 is the metering circuit schematic diagram.Sample electric capacity box [9] inserts jack CZ by the plug that concentric cable [10] connects ₁With resistance R ₁Be in series and insert voltage source composition RC circuit, the K that closes a switch, power supply E is by U5 voltage stabilizing, C ₆Filtering is after R ₁Equivalent capacity C to electric capacity box [9] _NCharging, be charged to equivalent capacity C behind certain level _NBy [RC] end discharge of U1:A, produce [RC] end that a sawtooth pulse signal that changes by index law is sent into U1:A again at this input end; Sample circuit is by U1:A, R ₁, C _NA multivibrator of forming constitutes, and in its [Q] output square wave arteries and veins, its pulsewidth is by the τ decision of input end [RC]; U1:B, R ₂, W ₁, C ₁, C ₂, C ₇The multivibrator of forming constitutes the τ basic pulse generator, is used to produce a known τ standard, and τ is by R ₁, W ₁, C ₂Value decision, at variable capacitance C ₂Adjusting knob on the index dial that indicates rosin water percentage and the corresponding scale of capacitance is housed, adjusting C ₂Can change the pulse width of U1:B output terminal [Q] output, C ₁, C ₇Be building-out capacitor, be used for distributed capacitance that the balancing a survey input end causes because of wiring, to reduce error; U2:A, R ₃, C ₃, R ₄Constitute trigger circuit, also be multivibrator, wherein a R ₃, C ₃Form RC network, [B] that trigger pulse is delivered to U1:A, U1:B simultaneously by [Q] output of U2:A holds, to trigger sample circuit and τ basic pulse generator synchronous working; U3:A is the comparer that d type flip flop constitutes, its input end [D] is connected with [Q] end of U1:A, input end [CLK] is connected with [Q] end of U1:B, the losing side wave impulse that the τ basic pulse generator that the sample circuit that is made of U1:A and U1:B are constituted is sent here is carried out peak pulse duration, and comparative result is sent into display and shown; Display is by the LED of Sheffer stroke gate U4:A, U4:B ₁, LED ₂, resistance R ₆, R ₇Form, when the square-wave pulse of sample circuit and τ basic pulse generator output compares through comparer, when pulsewidth is consistent, the input end of U4:A [15-1] is a high level, output terminal [15-3] is a pulse square wave, the input end of U4:B [16-1] is a high level, and output terminal [16-3] is a pulse square wave, LED ₁, LED ₂Pulse current is all arranged, because the inertia effect of naked eyes vision, so feel that two light emitting diodes are simultaneously luminous, represent that sample to be tested reaches balance with standard this moment; From C ₂The reading that indicates on the adjusting knob index dial is learnt the water percentage of rosin to be measured; R ₆, R ₇Play metering function; U2:B, C ₄, R ₅, C ₅, R ₈Forming delay circuit, [Q] end and the U4:A[15-2 of U2:B] [16-2] of end, U4:B be connected, and postpones a period of time by [Q] end control display of U2:B and for example just worked in 1 minute, and purpose is to stablize a period of time to sample, to reduce error.

Claims

1, a kind of fo moisture content in rosin measurement mechanism comprises a capacitive transducer (the sample electric capacity box that has parallel plate electrode) and parameter measuring apparatus, and two parts are disconnected from each other, is connected by a concentric cable, it is characterized in that:

Described sample electric capacity box [9] is made up of the pole plate of two parallel symmetries adorning in housing and the housing at least, and limit end extraction electrode is connected with an end of concentric cable [10], is used for the splendid attire sample to be tested;

Described parameter measurement partly comprises

A, a resistance R ₁Insert voltage source composition RC circuit by concentric cable [10] and electric series connection of sample electric capacity box [9], to obtain sampled signal;

B, one have the sample circuit [11] of two input ends [RC], [B], the other end that [RC] end connects concentric cable [10], be used to take out the sawtooth pulse signal of the RC=τ that changes by index law, and export the losing side ripple signal of a pulse width by the RC decision at its output terminal [Q];

The basic pulse generator [12] of c, RC=τ that output pulse width is adjustable is used to produce a known τ standard negative pulse square wave signal, is exported by output terminal [Q];

D, a trigger [14], its output terminal [Q] are sent a narrow negative pulse and are transported to the input end [B] of sample circuit [11] and the input end [B] of τ basic pulse generator [12] simultaneously, are used to trigger this two circuit synchronous workings;

E, a comparer [13], its input end [D] is connected with the output terminal [Q] of sample circuit [11], input end [CLK] is connected with the output terminal [Q] of τ basic pulse generator [12], be used for the negative pulse square-wave signal that these two circuit are sent here is carried out peak pulse duration, comparative result is sent into input end [15-1], [16-1] of display [15], [16] respectively by its output terminal [Q], [Q];

[Q] of f, a chronotron [17] end is connected with input end [15-2], [16-2] of described display [15], [16], is used to control display [15], [16] and prolongs chi a period of time and just show comparative result;

G, a described display [15], [16], its output state are determined by the state of its corresponding input end [15-1], [16-1], are used to show whether sample to be tested and standard reach balance.