DE2452555A1 - METHOD AND DEVICE FOR LIQUID LEVEL MEASUREMENT - Google Patents

Description

Method and device for measuring liquid saturation c

The invention relates to a method and a device for liquid level measurement by transmitting a microwave signal with a frequency that changes as a function of time to the liquid level ₉ Receiving a signal part reflected by the liquid level after a delay time corresponding to the distance between a reference point and the liquid level and mixing the reflected signal part with the transmission signal present at the same time for generating a differential frequency corresponding to the distance, the microwave signal being transmitted in such a way that it can be received with a delay corresponding to a known distance and converted in an analogous manner into a reference frequency corresponding to this known distance, in order to then determine the differential frequency to refer to the reference frequency ₈ that the distance calculation is based on the previously known distance.

509822/0616

BATH ORIGINAL

35a Microwaves have an extremely low speed, they are particularly suitable for precise sntferaungs · »tmci distance sjaessungesa", as shown in the British latent soYalf.t 1 10Ö 119o. When working with Milcvovrellen Haö ^ ore-ricbtuagea _P which is essentially stawbunsensiadlich asboitöPp aie Meeeung without any control with the liquid level ₅ ^ as in many cases a portion of the gate iat,

The present invention is with beaoaaorom? Oz * 1; eil ■ v / endable for the FLüeeiglcelteBtandmeemang Iu fsnlcsy apielaweise in the 3? lüssiglcei1; sF; peiel5ertßnfeö from faaic; * - aohiffeaa

If isaa but z _a B _a with the help of the Hilcrovelle ^ F mirror oil veriBieatp stollea 'see ssblreieb © JfaSztoxen ® ± n « which adversely affects the accuracy of the measurement. % u, the factors include the difficulty of accurately the ^ achieved ifferonzfrequaaß, also fixed B or separation of Störrefle'x'ionen of examples, in the would sink or the lankböden arranged 5Prä ^ © rn.> the Hiöht-üinearitSt the Mikrovielleuiuells or other TJmrol3.koamienheiten des Milcrowelleasendero, i5m * Terbesaerung the measurement accuracy iöfc baiapieleweise already been proposed in the brit, patent 1 207 566 _t

509822/0616

(ij.nr) Bc3ugrwv ^r & 37 Delay to which the liquid

related to

The object of the present invention is to provide one berried measuring method © and an improved heating

the exact heat with the help of microwaves delivers », only meets very modest requirements

ät deo IW.krowellenseBdere represents and eur gleielieti Time also nohosn uneapfinaiioh for annoying reflections lot η

erf iüdimgegemSße measuring method is characterized ,, that the Difförensfrequens and Beeugsfrequenz XAIT a Pakbor are multiplied _s which within the same length (Deilintervalle the Abtast2eit constant let _P verifiable but during the Abtasteeit at the end of 3eden TeIlintervaließ gradually changes _t then individually the products ouch factor and to sum frequencies "so that at the end of the sampling time a quotient can be formed between the sums obtained, which is a hatred for the distance sought

A device with a microwave generator for microwave signals with a frequency that changes as a function of time, one with the frequency, is suitable for carrying out the method

509822/06 16

Generator verbmsäeiaesa ₉ with respect to their distance au measured surface geriehtetes i & temie & ur Abstrabüung of MikroYiellensigßale and sum Kapfaetg of from fflüeeigkeitssplegel reflected "signal portion, a first mixing stage swisekQQ Jkateune New York Convention 0 @ eerator mm mixing reflected and auegesaBdeter Mi ^ @ w @ ll @ HBlg »@ l @ .uud: SrzeugQn of the distance ent ^ pr & uliemdeii $ i ££ £ ®mmi% ®quetiz _f a iÄ with the generator ^ / © © rtaad a®ii member ₉ S @ 3 @ © Teaisögeruugsseit a known distance © ats ^ i © bt _f © in @ r sielt 'Misebstufe sw £ s @ h © B ikinahmm mä ^ däigli @ d ₉ eis MMvhm der

iet,

ianerbalb one constant iet _? siefc

and that with the Terrlelfaabesn a «fei Mdieir & r and that the Produkt® from Taktor and XreojuenBen during add the sampling time and a quotient btXdaer epeleen, weloner at the end of the time of defrost between the Sunoes of the Adder forms the quotient

50 9 822/0616

Much © Siasselheiten and mer & times of the invention result refer to the following detailed description and άen attached drawings, in which the invention, for example illustrated is *

the drawings show:

a Liechteckäiagraam one according to the invention Device for

a rectangular diagram for a Hechner component the pig. 1" ·

Time amplitudes ^ Uisgraome of signals to be « The points of the rectangle diagram agreed

1,

4 a scheioatieche partial representation of a lane with a plurality of inventive liquid-tape heaters and

Figure "5 in a partially sectioned view of a

Rope of the measuring devices shown in Fig. 4 O

B09822 / 0616

Cten & e! Pig. 1 is a transmitter 1 via three connections 3, 4, 5 a with a signal processor 2 verbund @a _e Xte signal processor 2 can load a number of Send © m aieü6B ₉ load »nan answer the ain ^ elsiaii SsraäerB @ ia @ sidliobe frontiiBMt · This side foil ? @rtdilung lets you work with the help of a cyclical systemöon tfalilere »dea? di® sohlußklenmian the friction © after with parallel gass <dem connects.

Sender belongs to . ülteow © il @ Bgfeii @ rator _β ν example, a üb with Tar &otösvA'betlnsiang vmBetcnQx Ooaillator, deseeB Eisgang *> r @ 1e @ Hiacbstofe 8 Mb antenna 10 verlmM @ ii I0t Zn eimv QhtaeiX ^ hQ 9 geriob ·· tet ISTF of Qov der Afcatanä gemansieE! At no 3.1, ϋ1) βτ a Yerötärkar 11 is the l € iBoh0tufa 8 such with the Jta-4 d © @ Sl ^ ial ¥ era3? T) 3itor @ Z vwsMsä & a » De ^ Hl» 6 lies an deoe i ^ soblußkleinme 5 dee S ₉ ? m over- this Mnsöhlxrßlzlimmjü with ab-

triggers a * Xre <peiffiebte @ tassg a m & ₉ 'at the Sieb d.lo la vesentlieben linear with time Sndei? t ₉ vri <»eis you Pig · 3 shows. Jtas the Hlßohstufö 8 e & follows a Sigaalabfluss, so that a rope dee Hi & rowellen & i & iiala from the transmitter θ via the antenna 10 srar Oborfl & cbe 9 · Sin! Beil the wave radiation impinging on the surface 9 is reflected in the antenna 10

50 9822/06 16,

ORIGINAL -

Una sue Misch stuie 6 Burttckgeleltet, 3fig · 5 seigt in des? first inch in dashed lines the course of the reflecting microwave signal. As eon Yig · 3 to he «ebQn, the signals have a unä to gleione SregueBBvalues ssu different points in time« Did lateral difference ontopricht. the run ait of the Mltrowelle ^ ie the distance from the Mi.it! Level 8 stu * Ot> er £ lScbG 9 uttd eurllok. 3M.ee beiS with öucioEQii words that cti iDestiinmteti Zeltpuntfceo. a BiffoTfeuzfreciUsaK ßi ^ iocbon the signaion β and t> present i # t, probably distance from the pre-mentioned tone atft & ogt · The task of MiBOhstufe 8 is to create a difference by mleohing the singles a ti a dif £ e * j? ei! zi £ egue & 20igBal ο also generate, which is shown in Fig. 3, you ea signal ο fewtau-TJnregGliformitäten boruhoii on etör «ftden Sohoöignalen -of objects, which are an ol> erbalb or undwrbalb the surface" or on Siohtlinöoritttt · © dee Sücrowelleneendere, disturbing Generating echoes · Objelcbe barrel atapielfWGisQ that are in 71g »4 eskeniinarea defensive carriers · The Eohoaignele coming from the explorers can interfere with the positive signals received Signal converter connected,

the flow of storm springs in a well-known manner

509 822/0616 BAD

au eliminate, let a © ses? Jrasg®ngaldL @ iBme des generatore another Usefcstuf® 13 cmgeeöaXosaea, the In similar to the mixing stage 8 tibev an amplifier 15 with the AasofoliifiteleanRft äee Sl ^ elveratftaitere £ toad Zeltglieä 14 vertaMi® is »Ιώ fibnlldher W © ise as with

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The ÄneohlußldeiiMe 3 in which the signal d in the signal ver-

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Worker 2 enters, leads via an event converter 16 and a pulse shaper 17 to a computer 18. In an analogous manner, the connection terminal 4 at which the signal c reaches the signal processor 2, via a controllable converter 19 and a pulse shaper 20, see below the computer 18 · the computer 13 is connected via a memory 21 having a inzölgevorriohtung 22 and further with a controller part 23, and a manual control 24 "She manual control 24 serves to influence the measuring method and sum introducing constants in the calculations · the Begierteil 23 and the output of the memory 21 are connected to the filter 19, the sin and outputs of which are input into an Aiaplituaenkomparator 25, the output of which again leads to the controller part 23. The controller part 23 is connected to the Site wave generator 6 via the Aasehlufi terminal 5.

The erequena multiplier 16 has the task of generating a signal e (see 7ig «3) of constant amplitude and a frequency which is a multiple of the? Requ * na dee signal d from the signal d. This! Frequency multiplication "speaks of an increase in the side member 14" If one really wanted to enlarge the side member 14, one would first increase the attenuation with subsequent chewing problems, and the second result would be a very large and expensive timing element. The Impulafonaer 17 converts the »signal β into a pulse train f with one pulse per half period of the signal» e ·

509822/0616

After the Borctalaufe »the ftastlrlß & re 11, the signal c la Ellter 19t a®» regtiTbavea Ssfe'malbaiidfiltar, filtered * Bieeee band filter 19 is so accurate that its mean frequency is set so that it is so .Qksf £ Gqi ££> n ^ d © e Be ^ ngsf ^ e ^ uem ^ saigüßls d proportional viTU with eirnr Signalgrl $ Be _$ üi® d ^ i filter 19 tmn manual control 24 via äea B.e3lortoil 25 becomes »Xtaroh this © MsSüabme is Θ3 isugli @ & ® gmrings

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Bas exit hall g äas filters 19 l @ t eis nal, äöosen KcequeBS an I-lass for deti ^ u keitaspiegel let “With the help of the ImpttlBiönnörD 20 dent signal g a Xs ^ fnlgieignal b gevo ^ # B, welobee for

dee signals g contains an impale · during the

Verar "beitutsg the Signal® is formed awiaehoc the two Xnpaleeign & len f UTID h a quotient, said. The arößenverhältnie äor impulses from BscSoutieg is Mq on the time toeBOga & en £ @ ge & the JDapulsö Warier. Niobt used _β During Quotientenbildnng verviendet lean oinon Wiohtigkeitefaktor 1, the course of which during a Abta & toing In the Pig, 3 is shown in the plumb line as an example. According to a special feature of the invention, these are used

509822/0616

in 2Pig, 3 shown importance effects * the norm n (If-n), ei K the Ληκ-abl of the essentially equally large

tfgurend de © AbtaetEyklueeeß und η öle Stm «· the rope interval let. Ee atöfct the numeral 1 for the first, and the S Buohetabe for letete leillu- "borrall" 3) sr Wiolitigkeltöfafetor ensures that the quotient _f aafttr swiaohon oil 3? Rootuenzen In the signals lastfl £ h fiacü a "m Vea? Fobren dor Itleinsten Quaflrote detects vird to 8cbcm after a single scan, an exactly "Beseeh- su enaSßllchen. Bin mmg constant Wlöhtigfeeltefelctor

r.ur Toswenäung a conventional tsnpulsaäblvörvor, volohee zxae Braielung a very large: ', ;; oino Irapulssäblung over a large number of

required, but still impressively disturbing ecboD is very unpleasant

The breakdown of the activity factor and the formation of the quotient according to the invention takes place in Heöhner 18, the structure of which is given as an example in Pig. Z is shown. The activity factor computer 26 receives the impulse signal b atio the impulse monitor 20 (fflg »i) · The calculated activity factor i is stored in a register 27 which controls the feeding of the signals f and h into two multipliers 28,29 · This Yer-n elfacber 28,29 © iod 3 each connected via adder-controller 30,31 with the quotient converter 32, Dae introduction

509822/0616 -Mon

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509822/0616

to the continuous signal processing "even then" when the amplitude has become so small due to external circumstances that it could be confused with signal amplitudes, which ironically Stureo signals can and otherwise there would be a risk of denial. Venn it is the ^ lüssigkeitsstandiBeasung in a Tankachiffhandelt, it may sometimes be necessary to work with an amplitude control since the .Amplitude by wave formation on the surface can be fflüsaigköit affect the "The implitudenJcoepaxator 25 ensures einö such control by daa Signal g, which "contains" the Elfferönsfrequena corresponding to the surface 9, compares it with a corresponding area "of a fixed bucket in or outside the antenna 10, then filtered out the echo from the signal c * Her coaparator 29 generates a logical signal is ea seen from the ^ if the desa to erreohnandon Plüssigkeitsstand enteparechende signal a gtö & ext or S ^ leinerA ieplitude as te · signal of a fixed Bohoa asked ο Bin such Tergleion ensures au ^ oh why the Tlüssigloeitsstandaeeeung fluctuations at the output of Mürowellengenorators 6 unahliängig _Q When the amplitude of the signal c ia comparison old Störun gen * insufficiently is, the controller part 23 interrupts the measuring process «

509822/0616

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50 9822/06 16

Claims (5)

Claims Method for measuring the liquid level by transmitting a microwave aial with time-dependent changing Irequeas sxtm ! Liquid level, receiving a signal part reflected by the liquid level after a delay time corresponding to the distance between a reference point and the liquid s * level and mixing the reflected signal part with the signal part that is present at the same time Senäesignal for generating a distance ent-. speaking difference frequency, the microwave signal being transmitted in such a way that it can be received with a delay corresponding to a known distance and can be converted in an analogous manner to a reference frequency corresponding to this known distance, in order to then relate the difference frequency to the reference frequency so that the distance calculation is based on the known distance is based, characterized gekennzelehnet ₉ that the difference frequency and the reference frequency multiplied by a factor / ground ₉ which ianerhalb equal long rope intervals of sampling time "1st constant, however, gradually changes v during Abtastaeit at the end of each sub-interval, and then individually the products from To sum up the factor and frequencies so that at the end of the sampling time a quotient can be formed between the sums obtained, which is a measure of the distance sought ₀ 509822/0616 2. The method according to claim 1, characterized in that the factor for ^ every single! and represents U for the last sub-interval _c 3ο method according to claim 2, characterized in that ^ every rope interval is equal to a half-period of the differential frequency is. 4 »The method of claim 1 to 3 _f characterized in that the reference frequency is multiplied by a constant which S® susgewählt i @ t ₉ SaB the FreqtieB thereby obtained ^ gi: S-Ber © 1 @ di @ Biffsr @ nz £ r @ (| .uenz becomes, whereby ale ^ Sie ¥ e £ zö * g @ 3? u & g © $ eit ve ^ gap ^ ßert ■ uad also the X & ng® of the © »AbBtaiiSe © always as the distance to be measured Ydrfehren according to Claims 1 to 4, characterized in that the differential frequency is screened with a band filter, the center frequency of which is regulated proportionally to the reference frequency in order to filter out reflections regardless of varying scanning speeds 509822/0616 6, Yerfsnren according to claim 1 to 5 _t gefcemicselehnet that the amplitude of the reflected microwave signal is compared with the amplitude of eiztea known echo signals in order to separate signals whose amplitudes are larger or smaller than a range close to the amplitude of the known echo signal » 7 «The method of claim 1 to 6, characterized in ₅ Âëàä the Sifferenzfrequens into a pulse train umgewaadelt ^ ill, the fzeqiwnz for 3ede half period of the Differena- a pulse contains ₉ wherein the pulses of a scan are input into a shift register _P whose Sehaltgesölwinäigkeit old the Beaugefrequenz is controlled in order to exclude the stored pulses in accordance with a linearization of the scanning with a uniform Q-speed _{or the like} 8, device 2 for performing the method according to claim 1 to 7 with a microwave generator for microwave signals with time-dependent changes Frequency associated with the generator the antenna directed with respect to its distance © ssu to emit the microwave signal «And to the reception of the liquid level 5 0 9 8 2 2/0616 ⁸ ^ D Or / _Q / _Nal reflected © "signal tones, a first" high level between antenna and generator for the elimination of reflected and emitted microwaves igraXe and HrseTagea a ctem distance corresponding differential frequency, an ax connected to the deaerator, whose yera time a "known Ibetand eatspricbt ^ a s Mieobstufe zxif The generator and the second generation of the delayed and the emitted microphones and generation of a signal frequency corresponding to a known distance, and a computer for the itoeolmusg of the signal by means of the binary reference frequency related to the output frequency , characterized in that the computer (18) contains multipliers (28 _g 29) which multiply the Bifferons "u" d suction frequencies (h _s f) with a factor (i) which is within ® ± ®qt. each half-cycle animal Differeasfre quena * (h) is constant but see ₉ during the sampling time is changed, and that are connected to the Ver ^ ielfacbexni C28,29) Awei adder (30,31) the Ss _s? oducts of laktor and frequencies during add the sampling time and feed a quotieatenbildner (32), which at the end of the sampling side between dea sums (m,!) of the adder (30,31) deYi quotiom * th forms " BAD ORIG 509822/0616 Blank page