CN2038238U

CN2038238U - Humidity-sensitive sensor

Info

Publication number: CN2038238U
Application number: CN 88215827
Authority: CN
Inventors: 邱安生
Original assignee: BENXI RELAY FACTORY
Current assignee: BENXI RELAY FACTORY
Priority date: 1988-11-04
Filing date: 1988-11-04
Publication date: 1989-05-24

Abstract

The utility model relates to a humidity-sensitive sensor which is used for measuring the moisture content of gas, solid, oil and emulsifier (milk) according to a magnetic sensitive principle. The utility model mainly comprises a humidity-sensitive sensing element, an amplifier (or a displayer) and an alternating current power supply. The curing stress of the magnetic sensitive vane is increased when the moisture content of the medium is decreased so that magnetic permeability is decreased. The stress is reduced and magnetic permeability is increased when moisture content is increased so that output voltage can correspondingly change. So the moisture contents of various medium, the solidification process of the substance whose medium is water, the stable state of cement buildings and inner stress change in a destructive process can be dynamically monitored.

Description

Humidity-sensitive sensor

The present invention relates to device with water cut in magnetosensitive sense principle measurement gas, solid, oils and emulsion (milk) liquid.Can dynamic monitoring be the speed of capillary effect of variation, the solid matter inside of internal stress in the material solidification process of medium with water, the variation of internal stress in dynamic monitoring cement works thing steady state (SS) and the destructive process.

Wet-bulb depression formula thermometer is arranged at present, with pottery resistive moisture sensor and the capacitance type humidity sensor made.

Above-mentioned moisture sensor all can not be measured in the fluent meterial as the water cut in oils, emulsion (milk), the soil, can not measure that water absorptivity solid matter interior moisture content changes and the relation of speed, internal stress and the humidity of capillary effect.

And resistance-type, condenser type moisture sensor operating circuit and output circuit all exist common port, is difficult to realize isolating, and is subjected to the external interference influence easily.

Task of the present invention is intended to overcome above-mentioned the deficiencies in the prior art, and a kind of water cut and the moisture sensor easy to adjust, good stability that can measure in soil, the fluent meterial is provided.

Task of the present invention reaches by following measure:

Utilize the stress effect of magnetic material in solidification process, promptly after the magnetic matrix surface is surrounded sealing by solidfied materials such as cement, clays, the magnetic matrix surface is produced solidification internal stress, after the certain hour solidification process was finished, the internal stress of water absorptivity solidfied material and its water cut had close corresponding relation.Because the influence of surrounding environment, when its water cut reduction, solidfied material stress increases, and forces the magnetic permeability of magnetic matrix material to descend, and the output voltage that is reflected to moisture sensor presents decline clocklike, and this process has certain reversibility.When outer layer absorbent solidfied material is influenced by media environment, by gaseous exchange, solid contact, capillary effect, liquid, aqueous conditioning such as topped, when water cut increases again, the internal stress of water absorptivity solidfied material reduces, thereby the suffered stress of magnetic matrix is reduced, magnetic permeability increases, and the output voltage that is reflected to moisture sensor increases.After the solidfied material water absorbing capacity reaches saturation value, output voltage will be stablized and remain unchanged.And this reversibility is to have optionally, have only when the solidfied material in the wet quick sensing element when surrounding medium absorbs or discharge moisture content, respective change just can take place in its output voltage, and when absorbing or discharging non-water class material gasoline, alcohol etc., the output voltage of moisture sensor remains unchanged substantially.Because the water cut and the surrounding medium water cut of solidfied material are closely related in the wet quick sensing element, after both reach mobile equilibrium, thereby can measure the humidity and the water cut of medium.

Fig. 2 influences synoptic diagram for the magnetic material fundamental magnetization curve is subjected to solidification internal stress, measured BH curve when wherein L1 is for the encirclement of no solidfied material, the BH curve that records under certain (as the 60%) condition of relative humidity after the outer solidfied material curing of L2 for wet quick sensing element, L3 is the wet quick sensing element BH curve that (relative humidity 100% or immersion aqueous solution) records under saturated suction condition.I1 remains unchanged when exciting curent, and by H=I1N1/L, magnetic field boundary intensity H remains unchanged, because μ=B/H, H is constant, and then μ and B are proportional.

Wherein: B is a magnetic induction density, and N1 is the number of turns of elementary winding, and L is the average length of magnetic path of magnetosensitive vane

Make H θ line, intersect at d, e, f point with curve L1, L2, L3 respectively, obtain corresponding B1, B2, B3 respectively, thereby calculate the magnetic permeability μ of each point ₁, μ ₂, μ ₃

We can be by the mensuration of cement solidification stress, thereby determine the change curve of magnetic permeability μ and solidification internal stress σ, as can be seen from Figure 3, at the d point during as σ=0, μ=μ ₁Solidify the back at the e point, relative humidity η=60% o'clock, μ=μ ₂Again the suction reach saturation value after at f point, μ=μ ₃Because the internal stress and the humidity of water absorptivity solidfied material have corresponding relation, thereby can draw the relation of the water cut in Fig. 4 magnetic permeability and the water absorptivity solidfied material, wherein the f point is the water absorbing capacity saturation point, at g point η=0, μ=μ ₄

By the law of electromagnetic induction: e2=4K1BSN2f * 10 ^-8Volt, wherein K1 is a ripple coefficient, and f is the frequency of ac excitation power supply, and N2 is the secondary induction winding number of turns of magnetosensitive sensing part, and S is the magnetic loop sectional area.

Because of B=μ H, H=I1N1/L

e2＝（4K1fN2S×10 ^－8）×（I1·N1／L）

e2＝Kμ

Consider that simultaneously factor T1 such as temperature is revised in the measuring process, obtained complete nominal data curve like this,

μ＝F（σ、η、T1）

Coupled computer is handled, and just can realize the kinetic measurement to the solidification process stress of materials such as cement.After solidification process is finished, utilize the reversibility of μ-η curve to obtain concerning e2-η curve and, reaching and realize kinetic measurement of the output voltage of moisture sensor and humidity to all kinds of humidity of media and water cut to the selectivity curve of different medium sensitivity.

The description of the drawings

Fig. 1-moisture sensor synoptic diagram.

Fig. 2-magnetic material magnetization curve is subjected to solidification internal stress to influence synoptic diagram.

Fig. 3-magnetic permeability μ and solidification internal stress σ change curve.

Fig. 4-magnetic permeability μ and humidity (water cut) η change curve.

Fig. 5-cement solidification process and in soil, air moisture sensor output voltage change curve in time.

Fig. 6-cement, clay hardening process reach the selection sensitivity curve to material.

The cement solidification process of Fig. 7-different proportionings and limit sucting wet curve.

Fig. 8-simple type moisture sensor circuit and family curve.

Fig. 9-control system circuit diagram.

Fig. 1 is the moisture sensor synoptic diagram, and magnetosensitive sensing part 1 is made up of magnetosensitive sensing substrate and the elementary field winding N1 that is wound with on substrate magnetic loop hole and secondary induction winding N2.2 join clay etc. for water absorptivity solidfied material such as cement, spy, 3 is dry winding N3,4 is the exciting curent input end, N1 and ac excitation power supply 7 are joined, 5 is secondary induction winding output terminal, N2 and measuring amplifier (or display) 8 joined, and 6 is dry winding connection end, and N3 and heating power supply 10 are joined.Magnetosensitive sensing part 1, water absorptivity solidfied material 2, dry winding 3, exciting curent input end 4, induction winding output terminal 5, dry winding connection end 6 have constituted wet quick sensing element.The solidification internal stress σ of solidfied material 2 and surrounding medium water cut, humidity η are closely related, and the magnetic permeability μ of magnetosensitive sensing part 1 is changed, when N1 is exchanged exciting curent I1, change corresponding at wet quick sensing element output terminal e2.

7 is ac excitation power supply, and its frequency f and output current I1 select decision according to wet quick sensing element magnetic circuit duty.8 is measuring amplifier or display (as voltage table), and 9 is control system, and inside can be furnished with computing machine and be stored the related characteristics curve, according to measured e2 value interpretation humidity η, stress σ, etc.; Send different instructions, the break-make of control heating power supply 10; Heating power supply 10 provides heating power to dry winding 3.

In sum, wet quick sensing element, ac excitation power supply 7, measuring amplifier (or display) 8, control system 9, heating power supply 10 have constituted moisture sensor.

Adjust the frequency f and the output current I1 of ac excitation power supply 7 when measuring, make the magnetosensitive sensing part be operated in the big position of BH curve slope, at this moment the output voltage e2 relative variation of wet quick sensing element is big.

Fig. 5 for the cement solidification process and in soil, air moisture sensor output voltage change curve in time.Listed the size of magnetosensitive vane among Fig. 5 .1, part 1 adopts the thick iron-nickel alloy of 0.8mm to manufacture, N1=2 wherein, N2=1, adopt the split conductor coiling, its mode of connection is all by shown in Figure 1, and dry winding N3 adopts φ 0.2 nickel filament coiling, R=12 Europe, heating power supply 10 adopts 6 volts of 5 watts of transformers, output voltages.Rectangular parallelepiped was of a size of 16 * 20 * 15mm after water absorptivity hardening agent 2 adopted cement, moulding, and the part 1 that is wound with N1, N2 is solidificated in the centre position.N1 connects 7 low frequency generators, make f=400Hz, I1=0.1A, N2 connects 8 measuring amplifiers, thereby record e2-t curve shown in Figure 5, a0a4 curve representation cement solidification process wherein, starting point during a0 table cement-free solidification internal stress, E0=340 μ V, behind cement grouting, its output voltage e2 descends along a0a1a2, eases up in a2 point t=8 days, e2=210 μ V, variation subsequently, a2a3 section water spray back e2 value is gone up to some extent, drop to a4 point t0A=12 days after the air dry, e2=195 μ V, cement solidification process is at this moment finished substantially.Obtain the a4b1b7 curve among humidity-sensitive element being put into the flowerpot soil of normal plants growth.A4b1b2 segment table transient curve wherein, when b2b3 segment table soil moisture content reduced, the decline of e2 value was at b3 point e2=190 μ V.After the expression of b5, b7 point is watered, humidity-sensitive element is at saturated suction back voltage rise maximal point, at b7 point e2=310 μ V is maximal value, through again humidity-sensitive element being moved into after tAB=13 days among the outside atmosphere, curve b7c1c2 represents 2 days transitional period, at c3, c5 point table measured wet quick sensing voltage maximal value e2=250 μ V under the mist condition is arranged in the morning, c4 point table air humidity is to record curve minimal value e2=180 μ V under η=50% condition, and that utilizes that wet-bulb depression method or other humidometers can demarcate moisture sensor output voltage and atmospheric humidity concerns e2-η ₁Curve, equally also can demarcate with soil moisture content concern e2-η ₂Curve, and utilize above-mentioned curve that soil moisture content and atmospheric humidity are realized kinetic measurement, depict e2-t curve as shown in Figure 5 and convert η-t curve to by the computer recording in the control system.The moisture sensor 15 minutes energy measurements under ventilation condition that constitute by the humidity-sensitive element of Fig. 5 .1 made go out atmospheric humidity and judge the saturated suction attitude of whether being in of depth of soils.

Fig. 6 is that cement, clay hardening process reach the selection sensitivity curve to material.Part 1 selects for use the magnetosensitive sensing part identical with parameter among Fig. 5 .1, outer firming body size to change 12 * 15 * 14mm into, save dry winding N3 and heating power supply 10, the external circuits of humidity-sensitive element is regulated 7 signal generators and is made f=400Hz, I1=0.1A by shown in Figure 1.Adopt cement respectively when 2, obtain the e2-t curve of Ga, Gc cement and clay hardening process (η=60% condition) thereby clay is a hardening agent, and Sa is the limit recovery curve of the saturated suction of cement.Among Fig. 6 .1 among e2-t1 and Fig. 6,2 the e2-t2 pencil of curves represent that respectively with cement and clay be hardening agent selection sensitivity curve to four kinds of different fluent meterials after forming firming body.As shown in Figure 6 at two kinds of humidity-sensitive element e2=330 of starting point of Ga and Gc μ V, with cement is that hardening agent 2-a is after 10 days, humidity-sensitive element e2=210 μ V(η=60% condition), behind its saturated absorption pure water, stationary value was e2=285 μ V after t1=5 divided shown in Fig. 6 .1, output voltage values e2=255 μ V after the suck up milk, this stationary value is mainly with the change of moisture content in the milk, when the water cut in the milk is higher, the e2 stationary value is higher, and humidity-sensitive element after the suck up milk is reentered in the pure water after also can reach 285 μ V values after 7 minutes.E2=210 μ V is constant after drawing gasoline, draw anhydrous alcohol after, e2 value slightly descends, after absorbing water, gasoline and alcohol overflows, the increase of humidity-sensitive element e2 value can be near 285 μ V again.With the clay is the humidity-sensitive element of hardening agent 2-c, and e2 reduces to 250 μ V from 330 after 1 day, and this humidity-sensitive element is drawn pure water respectively, can obtain four curves of the e2-t2 shown in Fig. 6 .2 behind milk, gasoline, the alcohol.The back 20 seconds e2 values that wherein absorb water return back to 330 μ V immediately from 250 μ V, at this moment lose solidification intensity.Returned back to 295 μ V in 20 seconds after the suck up milk, e2=250 μ V behind the absorption gasoline, the e2 value slightly descends behind the absorption alcohol.By above-mentioned curve as can be known: water cut difference in the liquid object such as milk, gasoline, alcohol, the voltage stationary value difference that moisture sensor demonstrates, as long as demarcate its e2-η (water cut) curve in advance, can carry out kinetic measurement to the water cut in the monitored fluent meterial.The suction capillary effect speed of clay seam is faster than cement layer as can be seen simultaneously.

Fig. 7 is the cement solidification curve and the limit sucting wet curve of different proportionings.Magnetosensitive vane size is shown in Fig. 7 .1 in the part 1, and material is a 0.8mm iron-nickel alloy plate, N1=2, and N2=1 adopts conductor cross-section 0.07mm ²Multiply ambroin wire-wound system.External wiring way is identical as shown in Figure 1, and adjust 7 and make f=400Hz, I1=0.15A, outer solidfied material forming dimension is 30 * 30 * 20mm, expects that wherein 2-a is a plain cement, material 2-b is added with 30% river sand.Two magnetosensitive sensing part 1-a that magnetic characteristic is identical and 1-b materials 2-a and 2-b are solidified into the rectangular parallelepiped size shown in Fig. 7 .1, at e2-t curve shown in Figure 7, wherein time coordinate adopts logarithmic coordinate, monitoring time 300 days, initial value e2=690 μ V when wherein humidity-sensitive element does not have solidification internal stress, and the time dependent e2-t curve of output voltage of curve Ga and Gb are illustrated in that 60% condition blanking 2-a and 2-b make two kinds of humidity-sensitive element A and B, and Sa and Sb represent to expect that 2-a and 2-b manufacture the two kinds of humidity-sensitive element A and the output voltage limit of B under saturated moisture absorption condition recover the e2-t curve.Particularly point out if direction shown in Fig. 7 .1 is added compressive stress P to humidity-sensitive element A and B in the time at tx to ty, (being no more than limit value) each curve Ga, Gb, Sa, Sb the difference shown in Fig. 7 can occur and descend, e2 value after compressive stress P disappears on each curve will be recovered initial value, as not recovering initial value, show that then outer solidfied material is in damaged condition bad.Utilize above-mentioned characteristic can the dynamic load that add of important concrete foundation be changed and to carry out dynamic monitoring, as long as in advance humidity-sensitive element is put into and is poured in the concrete pedestal prefabricated component, demarcate e2-σ curve exciting curent I1 in addition in N1, but the variation dynamic monitoring building foundation internal stress (intensity) by N2 output voltage e2 and add dynamic load and change, whether structure is damaged.Can carry out dynamic nondestructive to the internal stress (intensity) of the solidification process of the cement of different labels proportioning composition and product thereof in addition measures, and the existing method of static testing is to carry out destructive strength test at 3 days, 7 days, the 28 days cubic blocks to 100 or the 150mm that are manufactured respectively, just can reach a conclusion, and that the present invention tests the sample piece is little, can carry out dynamic nondestructive measures, and test sample piece can be done the humidity-sensitive element use subsequently, also can forever preserve.

Fig. 8 is simple type moisture sensor circuit and family curve.

Fig. 8 .1 is a magnetosensitive vane size, and the coiling window size is 7 * 10mm after the thick iron-nickel alloy plate of part 1 material employing 1.0mm, the punching out, and N1, N2 adopt φ 0.2 high-strength color painting wire coiling, N1=40 circle, N2=160 circle.Suction hardening agent 2 adopts cement, behind the solidified forming shown in Fig. 8 .1 rectangular parallelepiped 30 * 19 * 15mm, part 1 is fixed on the centre position, in the normal condition maintenance after 10 days, connect by circuit shown in Figure 8, can carry out kinetic measurement to the humidity (water cut) of medium, wherein B is a power transformer, alternating current 220V AC voltage transitions is become the alternating voltage of secondary V=6V f=50Hz, K is a power switch, BX is a fuse, W is 150 Europe 5W WW POT, be connected to the interchange milliammeter in the secondary loop, N1 by part in field winding input end 4 and the humidity-sensitive element joins, the resistance value of regulating W1 makes I1=0.2A, 8 is milivoltmeter or digimer, with 1,2,4,5 humidity-sensitive elements that constitute are placed in the air (or medium) of different humidity, the employing humidometer compares, promptly obtain the relation curve that the moisture sensor output voltage e2 shown in Fig. 8 .2 changes with humidity of media η, after above-mentioned moisture sensor connected control system 9, can be to storehouse, soil, the humidity of mal-condition (Korrosionsmedium) is monitored, and can report to the police after overshoot requires or takes measures automatically to regulate by control system.

Fig. 9 is the control system circuit diagram, has adopted a voltage comparator, constitute by F007 operational amplifier and BG13A * 62 and accessory circuit, can with compare from wet quick sensing element (device) output voltage signal.When the output voltage of reflection humidity of media (water cut), solidification internal stress reaches predetermined value, relay J 1 adhesive in the executive circuit, green indicating lamp XD2 is shinny, hummer FM sounding, major loop repeat circuit J2 action, by the conversion of its contact, control some water facilities and air-conditioning equipment, adjusting humidity of media (water cut) is no more than the defined value.

The circuit working principle: adopt 220V, 50Hz industrial power, K1 is the major loop gauge tap, and when the K1 closure, the elementary N1 of transformer B1 connects, secondary N2 output 9V alternating voltage, and red led XD1 is bright, and apparent source is connected.Secondary N3 and N4 are for exchanging 15V voltage, after QSZ full-bridge rectification and the voltage stabilizing of F8331 integrated package, export the working power of positive and negative 12V DC voltage at A, B two places respectively as voltage comparator and driving stage, BX1 and BX2 are the 0.25A fuse, C1, C2 are the electrolysis filter capacitor, and C3, C4 are high-frequency filter capacitor.

Output voltage (reflection humidity of media, water cut) by moisture sensor shown in Figure 8 between 8～24mV, enters comparator circuit through coupling capacitor C 5, adjusts potentiometer W1 in advance, make waver in position, to obtain suitable intrinsic standoff ratio, determine that the valve of F007 ends voltage, press following formula:

U1=U0/R0+RN U0=12 volt

R0 determines by potentiometer W1, and RN is by selected among R1, R2, R3 and the R4, and when ending magnitude of voltage U1 from the signal (reflection measured medium humidity, water cut) of wet quick sensing part (device) and predetermined valve and equate, F007 exports and bears step.

DW1, DW2 are stabilivolt among the figure; 2CW6～7.5V; D1, D2 be 2CP12 wherein D2 for the protection diode; prevent the superpotential damage BG1 that J1 produces; wherein J1 adopts JRX-30F sensitive-type 6V relay; J2 can adopt high power relay, its contact control soil sprinkler motor or air conditioner power supply.

Claims

1, a kind of moisture sensor, by wet quick sensing element, AC power, amplifier, parts such as controller are formed, it is characterized in that: suffered solidification internal stress increases the magnetic permeability that utilizes magnetic material and occur clocklike descending when the media water-bearing amount reduces, be reacted to also regular thereupon this specific character of decline of output voltage of wet quick sensing element, this characteristic has reversibility, the magnetosensitive sensing part 1 that use is made by the magnetic material of STRESS VARIATION sensitivity, be filled with water absorptivity solidfied material 2 on every side, and be placed on the centre of dry winding 3, and be equipped with respective terminal, constitute wet quick sensing element, the magnetosensitive sensing part has closed magnetic loop, there are two electric loops to be coupled on it, elementary field winding N is arranged in the primary return with it ₁, N ₁Join through exciting curent input end 4 and ac excitation power supply 7, secondary induction winding N is arranged in the secondary loop ₂, N ₂Two ends resulting secondary induction voltage e2 is connected N through output terminal 5 with measuring amplifier (or display) 8 ₁, N ₂Have good external insulation,

Wet quick sensing element and ac excitation power supply 7, measuring amplifier (or display) 8, control system 9, heating power supply 10 constitute moisture sensor.

2, moisture sensor according to claim 1 is characterized in that: water absorptivity solidfied material 2 is to make with cement or clay.

3, moisture sensor according to claim 1 is characterized in that: magnetosensitive sensing part 1 is the magnetic part with one or more closed magnetic loops.