Jan. 14, 1947. N. BREWER 2,414,086 FLUID METER Filed Nov. 25, 1943 3 Sheets-Sheet 3 #2294 '1 VEN TOR. Brewer 8?’ remedies. 14, 1947 * 1 2.414.086 ' UNITED ,sra'rizs ‘PATENT orrlcs __ 24141086 .rwmmrran" _ _ _ Nathaniel Brewer, Hat?eld, l’a., assignor to Fischer & ‘Porter Company, Hatboro, Pm, a cor poration of Pennsyl Application November 25, 1943, Serial No. 511,019 1 ' ' 9 Claims. (01. 73-209) The present invention relates to meters respon sive to‘variations in a variable condition and it relates more particularly to meters for remote indication, recording and integration of a varia ble condition, such as, for example, ?uid flow. ‘An object of the present invention is to pro vide means for accurate remote indication, re cording and integration oi.’ rate-of-?ow of a ?uid. 2 and an upper outlet fitting 14 adapted for con nection to an outlet pipe-line or’ the like, the ends of the metering tube l2 being held. in ?uid tight sealing relationship with stu?lng boxes I! and ii of said ?ttings l3 and 14 respectively, by means of lower and upper packing rings I1 and I8 and lower and upper adjustable stu?lng glands i9 and 20 respectively. ' Other objects and advantages oi.’ the present A metering ?oat 21 includes an uppermost coni invention are apparent in the following detailed 10 cal ?ow-‘constricting head portion 22 adapted for description, ‘appended claims and accompanying free up-and-down movement within said meter drawings. K “ . . ' ing tube l2 and an elongated closed tube 23 ex For the purpose of illustrating the invention, tending downwardly from said head portion 22. there is shown in the accompanying drawings one A well 24 of suitable corrosion-resistant non form thereof which is at present preferred, since 15 magnetic‘ material extends downwardly from the the same has been found in practice to give sat lower‘ end of the metering tube l2 and through v isfactory and reliable results, although it is to i the inlet ?tting l3, a drain valve25 being pro be understood that the various instrumentalities vided in the lower end of the well 24. . ' , of which the inventionconsists can be variously The well 24 is open at its upper end, so that arranged and organized and that the invention 20.it is, at all times, ?lled with the ?uid being is not limited to the precise arrangements and or-_ metered. The extension tube 23 of the meter ganizations of the instrumentalities as. herein ing ?oat 2! extends downwardly within the well shown and described. 24, the tube 23 carrying a. soft iron armature 2B Referring to the accompanying drawings in - within its lower end. ' which like reference characters indicate like parts 25 Cutside the well 24 and around it are wrapped ' throughout: ’ , upper and lower sets of balanced impedance trans Figure 1 represents a schematic view of one embodiment of the present invention. Figure 2 represents a view, on an enlarged. mitter coils 21 and 28. , The position of the impedance coils 21 and 28 may be vertically varied by means of lowermost scale, showing the magnetic switch mechanism of 30 screw-threaded adjusting nuts 29 working against the embodiment of Figure 1. the uppermost coil spring 30. ' Figure 3 represents a vertical cross-sectional A-case 3| surrounds the impedance coils 21 view of the rotameter indicating and transmit and 28 and is provided with a box 32 from which ting unit of the, present invention. . ‘ Figure 4 represents an elevational view of the 35 the lead wires to the coils emerge. I An outer removable casing 33 having a win dow 34 therein surrounds the metering tube l2, ‘ invention, parts being broken away better to re a scale 35 being positioned alongside the tube I2 veal the construction thereof. whereby the position of the metering ?oat may Figure 5 represents a wiring diagram illustrat be read o? against the calibrations/on the scale. ing the manner of connecting the transmitting 40 The impedance transmitter coils 21 and 28 are . and receiving coils of the impedance bridge. electrically connected to a pair of balanced im In the embodiment shown in the drawings, a pedance receiver coils 36 and ‘31 as shown in 'rotameter, indicated generally by the reference ’ the wiring diagram of Figure 5. impedance bridge receiving unit of the present character I0, is adapted to indicate rate-of-?ow The ~ laterally-disposed receiver coils 36 and of ?uid through a pipe-linear the like and is also 45 31 are identical in construction, the coils being adapted electrically to transmit the rate-of-?ow wound about cores 38 and 39 which are hard glass to a remote receiving unit shown in Figure 4 tubes having mirror-smooth cylindrical inner which is adapted continuously to record the rate bores of extreme accuracy.v »of-?ow and also to indicate total ?ow of ?uid iron armatures 40 and.“ are disposed passing through the rotameter during a predeter 50 forSoft free up-and-down movement within the cores mined period of time. 38 and 39 respectively, the armatures 40 and 4| The rotameter It, as shown in Figure 3, in being supported from opposite ends of a balance cludes avertical downwardly tapered transparent beam 44 by ?exible cords 42 and 43 respectively. metering tube I2, a lower inlet ?tting i3 adapted for connection to an inlet pipe-line or the like 55 The ends of the beam 44 are formed as verti-‘ cal arc segments 45 and 46, the cords 42 and 43 ‘2,414,030 3 4 being connected to the tops of the segments 45 ' bores reduces this friction and resulting error and 46 and extending downwardly over the seg to a minimum. ments so that the armatures 49 and 4|. always - ' - Furthermore, the use of glass cores together hang in the same vertical lines. there being no . with the vertical arc‘segments 45 and 46 on the lateral movement or the armatures with tilting 5 ' balance beam 44 (the vertical arc segments 45 and of the balance beam 44. _ The balance beam 44 is provided with an invert ed V-groove 41 which rests upon knife edges 48 to permit tilting of the beam. The beam 44 is provided withv an adjustable weight 49 for bal-' 10 ancing the beam. 46 maintaining the'armatures 40 and 4| at the same-vertical line regardless of tilting of the beam 44) permits the use‘ of smaller diameter cores which, in turn, allows-more windings to be placed upon a core of a given axiallength. This increase in the number of windings possible increases the ' A pen arm 50 is pivoted as at 5| and is con ‘ strength of the magnetic ?eld created by the nected to the beam 44 by suitable linkage 52 coils and thus increases the sensitivity of the im pedance bridge. ' whereby the pen arm 56 will be moved upon tilt ing of the beam 44,‘ a pen 53 on' said arm 50 being 15 The balance beam construction of the present adapted to record said movement upon \a chart invention has a further ‘advantageover conven 54 which is rotated by a synchronous electric tional constructions in that the use of inverted motor 65. > V-grooves 41 on the beam 44 restingv upon knife The operation of the present invention in re edges 48 on the beam support protects the ‘knife cording r'ate-of-?ow of ?uid will now be described. 20 edge from dust or other foreign matter which When there is no upward ?ow of ?uid through V ' would cause deterioration or loss of sensitivity (as the metering tube l2, the metering ?oat 2| , being ~ distinguished from conventional beam construc somewhat greater in speci?c gravity than the tions in which exposed knife edges are carried ?uid being metered, remains in its lowermost by the beam and are supported from underneath). position. As rate-of-?ow increases, the ?oat rises 25 , The mechanism thus farf described has for its within the‘metering tube l2, the height of the , purpose the-remote indication and recording of ?oat indicating rate-of-?ow in a manner well known in the art. , the rate-of-?ow of ?uid passing through the rota meter |ll.~ The present invention also includes means for integrating the ?uid flow so as to reg Movement of the metering ?oat 2| responsive to changes in rate-of-?ow causes corresponding 30 ister the total amount of ?uid which has passed through the rotameter l0 during any elapsed peri changes in the position ‘of the armature 26 rela od of time. tive to the impedance transmitter coils 21 and 28; the higher the metering ?oat, the greater is the This mechanism, which is shown particularly in Figures 1 and 2, includes a conventional elec proportion of the armature. 26'within' the upper impedance coil 21 and correspondingly less is the 35 trical counter 56 which is adapted to make one numerical count in the unit digit column with proportion of the armature 26 within the lower each break of the electrical circuit following a impedance coil' 28. As is well known in the art, the impedance of the upper coil 211s thus in- ' make of the circuit; the'period of time during which the circuit remains open or closed being creased while the impedance of the lower coil 28 is correspondingly decreased. 40 In the balanced electrical circuit shown vin Fig ure 5 this variation in impedance will vary the current in the receiver coils 36 and 31 and will ‘ immaterial. ' The make and break of the circuit is accom plished by means of a magneticallyeactuated mer cury switch 51 which is operated by a permanent bar magnet 58 in a manner to be hereinafter tend to move the armatures 40 and 4| to corre sponding positions within their respective coils. 45 described. _ The mercury switch 51, as shown particularly in Figure 2, includes a sealed glass body 59 having a That is, as the armature 26 moves upward rela tive to' the transmitter coils 21 and 28, the greater impedance of the upper transmitter coil 21 de creases the current‘in the left hand receiver coil small lowermost well 60 which contains a bead of mercury 6|. A ?xed electrode 62'extends down 31, while the lesser impedance of the lower trans 50 wardly from the top of the body 59 and into the mercury bead 6|. mitter coil 28 increases the current in the right hand receiver coil 36. In this way, upward move An arm} 63 is mounted at the top of the body 59 and supports one end of a spiral hair spring 64, ment of the armature 26 will cause a downward the other end of which extends downwardly and movement of the armature 40 and an upward movement of the armature 4| to result in a clock 55 terminates in a plate or ?ag 65 of iron or the like which is sensitive to magnetism. Extending gen-' wise tilting-of the balance beam 44. Similarly, erally horizontally from the lower edge of the downward movement of the armature 26 will re sult in a counterclockwise tilting of the balance ?ag 65 is a wire 66 the other end of which termi beam 44. nates in a generally vertically extending mova It is ‘apparent, therefore, that movements of 60 ble electrode 61. The horizontal wire 66 is sup- ‘ the metering ?oat 2| responsive to variations in ported intermediate its'ends by a looped rod 68 rate-of-?ow will be duplicated by movements of descending from the arm 63. the pen 53 upon the rotating chart 54 to give a In its normal position the mercury switch 51 continuous record of the rate-of-?ow. . v is open; the movable. electrode 61 being held The use-of hard glass cores 38 and 39 for the 65 clear of the mercury bead 6| as shown in dotted coils 36 and 31 affords‘ distinct advantages over lines in Figure 2. When, however, either pole of conventional constructions. the bar magnet 59 is brought adjacent the right Thus, it is well known that, in an impedance hand side of the mercury switch 51, the magnetic coil,‘ the armature is pulled up‘ against the side’ , attraction will move the ?ag 65 to the right of the .core by the magnetic ?eld so that a cer 70 against the tension of the-hair spring 64 until the tain amount of friction results which, in conven ,- switch assumes its closed position, shown in solid tional constructions, constitutes a serious factor lines in Figure 2, in which the movable in determining the sensitivity and accuracy of ‘electrode 61 enters the mercury bead 6|. So the unit. The use of glass cores having extremely long as the magnetic ?eld from the magnet 58 is hard and smoothly accurate cylindrical inner 75 uninterrupted the mercury switch 51 will remain ' ~ ‘ 5. - closed; the upper end of the ?xed electrode‘ 82 and - and'a correspondingly'greater rotation of ‘the to the upper end of the arm 88 (which is in electri talizer wheel 13. ' ‘ cal connection with the movable electrode 81‘ through the spring 84, the flag 88 and the wire 88) passing‘ through the body 88 of the mercury’ switch and connecting with a cable 88 leading to the counter 88. ' - , ' - The calibration cam '82 is mounted upon a shaft .84, the other end of which carries a pinion gear . 88. which is in engagement with a rack 88, the rack 88 being connected to the beam 44 by means , 01' an arm 81 so that tilting. of the beam 44 causes ' Immediately upon interruption of the magnetic ?eld from the magnet 458, the movable electrode rotation of the pinion 85 and of the calibration cam 82. This connection‘is so effected that clock 81 will ‘be moved to its open position by the spring 10 wise tilting of the beam 44 upon increase in rate 84 to breakthe electrical circuit and to operate of-?ow produces a counterclockwise rotation of the counter 58. , . a _ a the calibration cam 82 and vice versa. \an interruptor wheel 18, which is of steel or The shape ofthe calibration cam is the same ' other magnetic material, is positioned interme as, the calibration curve of the rotameter as diate the bar magnet 58 and the mercury switch 51. The interruptor wheel 18 is provided with a plotted on polar coordinates, so that the length of the upsweep‘ of the pen 83 and the extent plurality of radial slots 1| whose function will be hereinafter described. The interruptor wheel. is ‘ of the upward movement of the actuator 11 bear the same proportion to the ,maximum upsweep keyed to' a rotatable shaft 12, the shaft 12 having and extent of movement 'as the instantaneous a totalizer wheel-18 keyed to its other end. -20 rate-of-?ow reading bears to themaximum rate The totalizer wheel has a hardened knurled of-?ow reading. Accordingly, the rate of rota periphery 14 which is adapted to be engaged tion (R. P. M.) of thetotalizer wheel 13 and upon upward movement of a pawl 15 mounted up on one arm 16 of a V-shaped actuator 11 which-v _ of the interrupter wheel 18- bears the same rela- , is loosely pivoted to the shaft 12 as at 18. The 25 tion to the maximum rate of rotation as the in stantaneous rate-of-?ow reading bears to the actuator 11 is swept upwa‘rd at‘ regular intervals maximum rate-of-?ow reading. J _ _ by an eccentric crank 18 hearing against the other It is apparent that, as the interruptor wheel arm 88 of said actuator 1.1, the eccentric crank be; 10 is rotated, the magnetic ?eld of the magnet ing driven by the synchronous motor 55 through a shaft 8|. , 58 is intermittently interrupted. That is,'when ' 30 ever an unslctted portion of the wheel 10 is inter While the uppermost limit of travel of the ac mediate the magnet 58 and the mercury switch tuator 11 is ?xed, its lowermost or starting posi 51, the metal of the wheel will de?ect the mag netic ?eld from the switch so that the switch of a calibrati n cam 82. That is, they actuator open. When, on the other hand, one of 11 is supported in its lowermost position by a pin 35 remains the slots 1| of the wheel 18 comes in line with 83 carried at the outer end of the arm 16 and rest the magnet 58 and the switch 51, the magnetic ing upon the periphery of the calibration cam 82. . ?eld of the magnet is free to actuate the switch . tion is variab e_ and‘ is governed by the position During upward movement of the eccentric ' and to close the electrical circuit. "crank 18, the actuator 11 is moved upwardly and From the foregoing explanation, it is apparent the knurled periphery 14 of the totalizer wheel 40 that the mercury switch 51 will automatically ?3‘is engaged by the pawl 15 to rotate the totalizer ' close the moment after the leading edge of each wheel counterclockwise as in Figure 1. ‘During a slot comes in alignment with the switch and the downward movement of the eccentric crank 18, magnet and will remain closed as long as the following each upward sweep, the pawl 15 is dis slot 1| remains in such alignment and that, as engaged from the knurled periphery "so that the 45 soon ‘as the leading; edge of each unslctted seg totaiizer wheel 13 does not rotate, the actuator 11 .' ment of_ the wheel 10 comes intermediate the descending until the pin 83 strikes the periphery magnet and the mercury switch, the switch will i oi‘ the calibration cam 82. . It can be seen that the‘ pin 83 will prevent the actuator 11 from following the eccentric crank to the bottom of the latter’s travel and, therefore, the upward movement of the actuator 11 on the next succeeding stroke will not begin until the ec - centric. crank 18 has moved upwardly su?icient automatically open to register one numerical count on the counter 56. Thus, the number of 0 counts registered on the counter 56 will be equal to the rate of rotation of the interruptor wheel 18 multiplied by the number of slots or segments onthe wheel. It follows, therefore, that the number of counts 1y to again contact the arm 88 and to lift the pin 55 bears the same proportion to the maximum 83 from the periphery of the calibration cam 82. ' number of counts as the given rate-of-?ow read ing bears to the maximum rate-of-fiow reading It is obvious, therefore, that the extent of trav of the rotameter. _ el of the actuator 11, and consequently the extent Since the total flow (?gured as gallons or of rotation of the totalizer wheel 13, is dependent upon the starting point of the pin 83 as deter 60 pounds or any other convenient unit) passing through the rotameter during any elapsed period mined by the position of the calibration wheel 82. ' of time at the maximum rate-of-?ow can read That is, if the calibration cam 82 is in the posi ily be determined, it is a simple matter to calcu tion shown in Figure 1, the pin 83 will be sup ported at a relatively high resting position so that 65- late the total flow actually passing through the rotameter during the same period of time by mul the actuator 11 will be engaged much after start tiplying the maximum rate of flow by an in ing of upward movement of the eccentric crank 18 so as to give a relatively small movement of the actuator 11 and a relatively small angle of rota tegrator'factor; the integrator factor being the ratio of actual counts to maximum counts- for the elapsed period. tion of the totalizer wheel 13. If, on the other 70 By way of illustration, if it is known that, at hand, the calibration cam were rotated counter maximum rate-of-flow, 500 gallons of ?uid will clockwise from the position shown in Figure 1 it pass through the rotameter in one hour and/that is apparent that the starting position of the pin the total number of counts at such maximum 83 would be moved downwardly to give a corre rate-of-flow is 320, and if it is found in actual spondingly greater. movement of the actuator 11 75 operation that only 160 counts were registered 9,414,086 v 1 during the hour. it is apparent that the total ?ow beam responsive to movements of said ?oat, said last-mentioned means comprising an alternating currentv impedance circuit including a pair of 'end-to-end co-axial transmitter coils disposed about said extension tube, an armature carried by saidelongated member and adapted to be indicate a total ?ow of 450 gallons. The integrating mechanism of the present in- , moved with said transmitter coils by said ?oat, which actually passed through the J rotameter during that hour was 250 gallons. Similarly, an actual count of 80 would indicate a total ?ow of 125 gallons, while an actual count of 288 would 'vention has several distinct advantages over a pair of generally vertical 7 laterally-disposed parallel cylindrical receiver coils, and a pair of totalizers heretofore employed. Thus, for exam ple, the counting is done 'without imposing any 10 armatures carried by said beam and extending within said receiver coils and adapted to be pulled appreciable load whatever upon the metering thereby so as to exert opposite moments upon ?oat. Furthermore, since the totalizer "‘feels said beam, the relative impedance of said trans out” the instantaneous rate of ?ow several‘ times mitter coils being varied upon movement of the a minute (for example, the totalizer can be set to make four sweeps per minute), the mechanism 15 ?oat-carried armature thereby to vary the cur rent ?owing in the respective receiver coils so as adjusts its rate ‘of counting with sufficient fre to vary the pull onthe respective beam armatures quency to ensure high accuracy. . Another advantage of the integrator of the ‘ and thus totilt said beam. , . v ' 2. In a system for remote indication of ?uid or more electrical counters at any convenient 20 rate-of-?ow having a rotameter including a ver .tical metering tube and a ?oat‘ada-pted for free location by simply connecting them in parallel up-and-down movement responsive to variations with the mercury circuit. in rate-of-?ow of ?uid through said tube and Furthermore, electrical ticket- or tape-printing having indicating means remote‘ from said rotam counters of conventional construction can be used eter; an extension tube disposed in‘axial align in place of, o'r'in addition to‘ the counter de ment with said metering .tube, an elongated mem scribed hereinabove. ber extending from said metering ?oat into said ,As shown particularly in Figures 1 and 3, the extension tube, a balanced beam connected to remote rate-of-ilow recorder and the integrator said indicating means, and means for tilting said can be combined in a single unit for convenient 30 beam responsive to movements of said ?oat, said last-mentioned means comprising an alternating While, for purposes of illustration, the inte grator mechanism of the present invention has . current impedance circuit including a pair of end-to-end co-axial transmitter coils disposed been described in connection with measurement about said extension tube, an armature carried of ?uid ?ow wherein it constitutes a. preferred embodiment, it is apparent that the integrator 85 by said elongated member and adapted to be moved within said transmitter coils by said ?oat, mechanism could be used equally well in con present invention is‘that it permits the use of 2 reading. _ - . nection with measurement of other variable con-_ ditions, such as temperature, pressure, etc. That I is, it is apparent that the calibration cam could be rotated by the action of elements sensitive to variations in other conditions. For example, the calibration cam could be rotated by a tempera a pair of generally vertical laterally-disposed parallel cylindrical receiver coils, and a Pair of armatures carried by said beam and extending within said receiver coils and adapted to be pulled thereby 'so as to exert opposite moments upon said beam, the relative impedance of said transmitter coils being varied upon movement of ture- or pressure-sensitive 'element such as a the ?oat-carried armature thereby to varythe Bourdon tube. The integrator of the present invention could 45 current ?owing in the respective receiver coils so as to vary the pull on the respective beam ar also be used, for examplevto integrate, into total miles covered, the readings of a speedometer in dicating miles per hour. Again, it could be used to integrate, into total pounds carried, the read ings of a continuous weigher measuring pounds 50 matures and thus to tilt said beam, said receiver coils being provided with cores of hard glass tub ing having an extremely smooth and accurate cy lindrical inner bore whereby the beam-armatures per minute carried by a belt conveyor or the like. little friction. The present invention may be embodied in other speci?c forms without departing from the will move within said receiver coils with very ' ‘ 3. In a system for remote indication of ?uid ' rate-of-?ow having a rotameter including a ver tical metering tube and a ?oat adapted for free 55 spirit or essential attributes thereof, and it is up-and-down movement responsive to variations therefore desired that the present embodiment be considered in all respects as illustrative and not in rate-of-?ow of ?uid through said tube and having indicating means remote from said ro restrictive, reference being had to the appended ‘ tameter; an extension tube disposed in axial claims rather than to the foregoing description 60 alignment with said meteringv tube, an elongated to indicate the scope of the invention. Having thus described the invention, what I ' ‘claim as new and desire to protect 'by Letters Patent is: 1 member extending from said metering ?oat into said extension tube, a balanced beam connected to said indicating means, and means for tilting said beam responsive to movementof said ?oat, 1. In a system for remotev indication of fluid 65 said last-mentioned means comprising an alter nating current impedance circuit including a pair ~ rate-of-?ow having a rotameter including a ver of end-to-end co-axial transmitter coils dis tical metering tube and a ?oat adapted for free posed about said extension tube, an armature car upeand-down movement responsive to variations in rate-of-?ow of ?uid through said tube and ried by said elongated member and adapted to be. having indicating means remote from said rotam 70 moved within said transmitter coils by said ?oat, a pair of generally vertical laterally-disposed par eter; an extension tube disposed in axial align allel cylindrical receiver coils, and a pair of ar ment with said metering tube, an elongated mem matures carried by said beam and extending with , ber extending from said metering ?oat into said in said receiver coils and adapted to be pulled extension tube, a balanced beam connected to said indicating means, and means for tilting said 75 thereby so as to exert opposite moments upon 2,414,086 ‘ said beam, the relative impedance oi said trans mitter coils being varied upon movement of the ?oat-carried armature thereby to vary the cur rent ?owing in the respective receiver coils so as - 10 for free up-andvldown movement responsive to variations in rate-of-?ow through said tube, and having an electrical counter; a magnet, a mag netically-operated switch adapted to actuate said .to vary the pull on the respective beam armatures counter, means for periodically interrupting the and thus to tilt said beam, said beam having magnetic ?eld of said magnet thereby periodically means at its opposite ends for supporting said to operate said switch, and means actuated by armatures generally in the same vertical lines re said metering ?oat for controlling said interrupt gardless of tilting of said beam. ing means for varying the rate of interruption 4. In- a system for remote indication and in 10 of said magnetic ?eld, thereby to vary the total tegration of ?uid rate-of-?ow having a rotam registered by said counter during said elapsed eter including a vertical metering tube and a ?oat time period. adapted for free up-and-down movement respon 7. In a system for measuring total ?uid ?ow sive to variations in rate-of-?ow of ?uid through during a predetermined elapsed time period, said said tube, and having indicating means remote 15 system having a rotameter including a vertical from said rotameter, and electrical counting metering tube and a metering ?oat adapted for means; an extension tube disposed in axial - free up-and-down movement responsive to varia alignment with said metering tube, an elongated tions in rate-of-?ow through said tube, and hav member extending from said metering ?oat into ing an electrical counter; a magnet, a magneti said extension tube, a balanced beam connected 20 cally-operated switch adapted to actuate said to said indicating means, means for tilting said counter, means for periodically interrupting the ~beam responsive to movements of said ?oat, said magnetic ?eld of said magnet thereby periodi last-mentioned- comprising an alternating cur cally to operate said switch, said last-mentioned rent impedance circuit including a pair of end means including a slotted interruptor wheel ro to-end co-axial transmitter coils disposed about 25 tatably mounted adjacent said switch, and means Y said extension tube, an armature carried by said v actuated by said metering ?oat for varying the elongated member and adapted to be moved with rate of rotation of said interruptor wheel, there in said transmitter coils by said ?oat, a pair of by to vary the total registered by said counter generally vertical laterally-disposed receiver coils, during said elapsed time period. and a pair of armatures carried by said beam and 30 8. In a system for measuring total ?uid ?ow extending within said receiver coils and adapted ~ during a predetermined elapsed time period, said to be pulled thereby so as to exert‘opposite mo ments upon said beam, the relative impedance of said transmitter coils being varied upon move system having a rotameter including a vertical metering tube and a metering ?oat adapted for free up-and-down movement responsive to varia ment or the ?oat-carried armature thereby to 35 tions in rate-of-?ow through said tube, and hav vary the current ?owing in the respective receiver ing an electrical counter; a magnet, a magneti coils so as to vary the pull on the respective beam cally-operated switch adapted to actuate said armatures and thus to tilt said beam, and means counter, means for periodically interrupting the connected to said beam for varying the rate of magnetic ?eld of said magnet thereby periodi counting of said counting means responsive to 40 cally to operate said switch, said last-mentioned variations in the rate-oi-?ow of ?uid. means including a slotted interruptor wheel ro 5. In a system for remote indication and in tatably mounted adjacent said switch, and means tegration of ?uid rate-oi-?ow having a rotameter ' for varying the rate of interruption of said mag including a vertical metering tube and a ?oat netic ?eld thereby to vary the total registeredby adapted for free up-and-down movement respon 45 said counter during said elapsed time period, said sive to variations in rate-oi-?ow of ?uid through last-mentioned means including a balanced said tube, and having indicating means remote beam, an electrical impedance circuit for tilting from said rotameter, and electrical counting said beam responsive to movement of said meter means; a balanced beam connected to said indi ing ?oat, and means actuated by tilting of said cating means, means for tilting said beam re 50 beam for varying the rate of rotation of said . sponsive to movements 01' said ?oat, said last interruptor wheel. mentioned means comprising an alternating cur- ' 9. In a system for measuring total ?uid ?ow rent impedance circuit including a pair vof end during a predetermined elapsed time period, said to-end transmitter coils co-axial with said meter; system having a rotameter including a vertical ing tube, an armature carried by said ?oat and 55 metering tube and a metering ?oat adapted for adapted to be moved within said transmitter free up-and-down movement responsive to varia coils, a pair of generally vertical laterally-dis~ tions in rate-of-?ow through said tube, and hav posed receiver coils, and a pair of armatures ing an electrical counter; a, magnet, a magneti carried by said beam and extending within said cally-operated switch adapted to actuate said receiver coils and adapted to be pulled thereby 60 counter, means for periodically interrupting the so as to exert opposite moments upon said beam, magnetic ?eld of said magnet thereby periodi the relative impedance of said'transmitter coils ' cally to operate said switch, said interrupting being varied upon movement of the ?oat-carried means including a slotted interruptor wheel ro armature thereby to vary the current-?owing in tatably mounted adjacent said switch, and means the respective receiver‘ coils so as to vary the 65 for varying the rate of interruption of said mag pull on the respective beam armatures and thus netic ?eld thereby to vary the total registeredby to tilt'said beam, and means connected to said said counter during said elapsed time period, said beam for varying the rate of counting of said ' last-mentioned means including a cam, means for counting means responsive to variations in the rotating said cam responsive to movement of said rate-of-?ow oi ?uid. " 70 metering ?oat and means for varying the rate 6. In a system for measuring total ?uid ?ow of rotation of said interruptor wheel responsive during a predetermined elapsed time period, to rotation of said cam. said system having a rotameter including a ver tical metering tube and a metering ?oat adapted NATHANIEL BREWER.