CA1050301A - Apparatus for measuring the proprieties of fluids - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The apparatus for measuring a property of a fluid relative to a given dimension has a sensor probe containing a quantity of wire to be deployed when it is traversing the said dimension, and a recording device including a record medium connected to the wire for recording signals sent by the sensor probe relative to the property. Means are also provided for moving a portion of the recording device at a rate substantially related to the rate of movement of the probe, and for compensat-ing for the change in the rate of movement of the probe due to the deployment of wire therefrom.

Description

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This application is a division of appllcation No. 898,215, filed 18th March 1964.
This invention relates to the measuring of various properties of the ocean or of a body of water with respect to depth and is an improvement in or modification of the invention described in our co~pending application No. 895,066 which describes and claims a system for measuring the properties of water a-t various depths from a vehicle moving relative to the water comprising, an aquatic probe containing a sensing element for sensing a property of the water, a first conductor portion coupled to said sensing element and contained within said probe, first spool means within said probe having said first conductor portion wound thereon, said probe having one end open for paying out the first conductor portion into the water at a rate sub stantially equal to the velocity of the probe through the water, vehicle mounted means for deploying said probe into the water including a second conductor portion coupled to said first conductor portion and having second spool means having said second conductor portion wound thereon, said second spool means being arranged for paying out said second conductor portion at a rate substantially equal to the velocity of the vehicle relative to the water so that the relative motion of said first and second conductor portions with respect to the water is sub-stantially reduced to zero, and receiving means coupled to said second conductor portion and responsive to said sensing element.
In large bodies of water, properties such as tempera-ture and salinity, change considerably with respect to depth.
There are man~ reasons why it is desirable to de-tect and record these properties at different points in the ocean. For example, the variation of temperature or the existence of low depth liquid layers at a specific temperature can seriously affect the properties of acoustical energy as it is propagated through ~503~)~
the water. Such changes deleteriously affect the performance of sonar devices such as weapons systems and commercial devices used, for example, for fish detecting purposes.
Various devices and methods have been proposed for ; the collection of the data necessary accurately to deterrnine properties of the ocean such as temperature and salinity over a wide range of depths. Heretofore, the proposed systems have lacked accuracy and reduction of the collected data has been time consuming and non-automatic. In addition, the present systems have been useful over only limited depth ranges, while requiring a reduction in the speed of the launching ship during the measuring periods.
In Application No. 89S,066, there is described an aquatic probe which contains a particular sensing device and which may be deployed from a ship or the llke. The probe re-turns electrical signals, indicative of the particular property being measured, to the ship via wire which uncoils from both the probe and the ship to minimize the effect of wire deployment on the vertical descent of the probe.
In a preferred embodiment of the invention described in the said copending application, the shipboard apparatus in-cludes means for recording the signals returned by the probe as a function of depth by correlating the depth of the probe to the probe's constant rate of descent. For the sake of accuracy, a signal may be g:iven the instant the probe hits the water to move a recording mediurn at a fixed rate accurately related to the probe's rate of descent~ The property sensing means of the probe may be connected in a bridge arrangement, with an additional wire added to the probe and coupled to the sensing means and bridge in such a manner as to cancel out the effects of the resistance changes in the signal transmitting wire due to ternperature varia-tions as the depth increases.

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~ ccording to the present invention, there is pro-vided an apparatus for measuring a property of a fluid relative to a given dimension, comprising: a sensor probe containing therein a quantity of wire to be deployed from the probe when the probe is -traversing the given dimension; recording means including a record medium connected to the wire for recording signals sent by the sensor probe relative to the property;
means for moving a portion of the recording means at a rate substantially related to the rate of movement of the probe, and means for compensating for the change in the rate of movement of the probe due to the deployment of wire therefrom.
In a preferred embodiment/ the record medium is graduated in the given dimension, and the means for compensating comprises increased distance between gradations for increasing dimensions.
Embodiments of the present inven-tion will now be des-cribed with reference to the appended drawings, wherein:
Fig. 1 is a drawing of an expendable ballastic bathy-thermometer according to the invention described in the said copending application;
Fig. 2 is a cross-sectional vlew of the bathyther-mometer of FigO l;
Fig. 3 is an exploded view of a portion of the bathy-thermometer of Fig. 2;
Fig. 4 is an exploded view of the cable spool mounted on the ship of Fig. l;
Fig. 5 is a perspective view of an aquatic probe employed in an embodiment of the present invention;
Fig. 6 is a perspective view of the aquatic probe of Fig. 5 mounted in its shipping canister;
Fig. 7 is a perspective view of a catapult apparatus for launching the aquatic probe;

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Figs. 8 and ~A are diagrammatic illustrations of the manner in which the catapult of Fig. 10 launches the probe into the water, Fig. 9 is a side view of a boom launching system for the probe, Fig. 10 is a diagrammatic illustration of the manner in which the boom launches the probe into the water, Fig. 11 is a side view partly in section of a tube launching apparat~s for the probe, Fig. 12 is a diagrammatic illustration of the manner in which the tube launcher of Fig. 11 launches the probe into the water; and Fig. 13 is a perspective view showing another embodi ment of the probe mounted in its canister.

Embodiments of the presente in~ention will be described relative to a bathythermograph or tem~erature sensing device, but it is to be understood that the principles of the present invention are equally applicable to devices which measure any property of a body of water as a function of depth.
As shown in Fig. 1, the apparatus includes an ex-pendable probe 10 which is deployed from a moving ship containing the electronic apparatus to which probe 10 is electrically coupled via wire 36. As will become more apparent hereinbelow, a fundamental feature of the apparatus is the fact that the wire is deployed in both horizontal and vertical directions to thus minimize the effect of wire deployment on the probe's descent.
As can be seen more clearly from Fig. 2, the probe 10 includes a housing 12, and a nose portion 14 which combine into a teardrop shape having a smooth, rounded, forward end extending rearwardly to a relatively small poillted rear portion 15.
Mounted within the housing, and centrally positioned therein is a tube 16 integrally formed with the housing. A thermistor 3(~1 element 18 is positioned in the forward portion 14 of the housing within the cavity 19 formed by tube 16, to allow ex-posure of the thermistor to the ambient liquid. Electrically connected to thermistor 18 are wire leads 22 and 23. Leads 22 and 23 extend-through tube 16, to cable 24 which is coiled upon cable spool assembly 26. Assembly 26 is mounted upon tube 16 by suitable means ~not shown), Mounted concentrically about tube 16 in a symmetrical manner is a weight 28 which may consist of any suitable material such as lead to provide the probe 10 with sufficient weight to move the unit down through the liquid at the desired rate of descent.
In the single wire system illustrated in Fig. 2, wire 23 leading from thermistor 18 is electrically connected to the conductive housing 12, while lead 22 is connected to the inner most end of the cable 24 coiled about the spool 26O mus, the ocean in this embodiment is utilized as the return signal path for the system. In the rear portion 15 of housing 12 there is located an opening 32 which serves to allow the exit of cable 24 therethrough.
As will be explained below, in preferred embodiments, one or two wire measuring systems are utilized in which the sea itself serves as a return path. However, the probe can be utilized with any number of wires and could readily be used, Eor example, in a three wire system with no sea return path.
Cable 24 is payed out through the rear of housing 12 to the pool on the signal-receiving vehicle 33, as shown in Fig. 1. Cable 24 is connected to cable 36 which is mounted upon spool assembly 34 as shown more clearly in Fig. 4. A
male connector 38 is secured to the end of cable 24 and female connector 40 is secured to the end of cable 36, thereby provid-ing for the connection of the two cables. Lead 22, extending through cable 24 is electrically connected to male connector 38.

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Thus the electrical connection with the thermistor 18 extends to cable 36 through insulating cable 24. Cable 36 is payed out through opening 42 in housing 44 of cable spool assembly 34. m e inner end of cahle 36 is connected through conduit 46 to suitable electronic receiving equipment 48 which inter-prets the signals received from the sensing elements.
The embodiment described hereinabove relates to a temperature measuring device; however, it should be understood that a system as described may be utilized to measure the pres-sure, salinity, speed of sound, light conductivity, density, etc. of the ambient liquid. m us, the aquatic device described herein may be employed in a variety of liquid property measuring capacities.
The system described provides for the continuous measurement of the temperature of the ambient liquid relative to its depth. The operation of the system can best be under-stood with reference to Fig. 1.
The cable spool assembly 34, positioned aboard the signal-receiving ship 33 allows cable 36 to be freely payed out to thereby provide for the horizontal motion of the ship.
Cable 24 stored within housing 12 upon spool assembly 26 is freely payed out through opening 32 to thereby provide for the vertical motion of the bathythermometer. It can be readily understood that by positioning a cable spool within the housing of the bathythe~nometer and another spool assembly aboard a moving ship a means is provided which allows the bathythermometer to fall freely since the cable holding the bathythermometer does not move in relation to the water in either a horizontal or vertical direction. This phenomenon is effected because the unwinding of the cable from spool 34, located aboard the ship compensates for any horizontal motion of the cable with respect to the water and the cable being payed out of the bathythermo ~6--~L~)5~36~
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meter eliminates any vertical motion of the cable with respect to the water. Thus the cable represented by the line in Fig. 1 does not move with respect to the water in either a vertical or a horizontal direction.
The system parameters involved are the continuous measurement of temperature with depth. Thus as the bathythermo-meter falls through the liquid the temperature of the liquid changes with the change in depth. These changes in temperature are sensed by the change in the resistance of the thermistor contained in the temperature probe exposed to -the ambient liquid.
m e signals representing the resistance values sensed by the thermistor are transmitted through cables 24 and 36 o-f the conduit 46 to the shipboard receiving equipement 48. It is es~
sential, therefore, that the depth of the liquid t-hrough which the temperature probe is passing at any particular instant be accurately known. m e rate of descent of the missile may be determined empirically to thereby allow the depth of the bathy-thermometer at any particular instant to be calibrated through the utilization of a time-scaled recording. Thus, the tempera-ture of the liquid at a particular depth may be accurately de-termined.
Form the foregoing it may be understood that any horizontal or vertical movement of the cable relative to the water would seriously impair the accurate determination of the depth of the temperature probe because the velocity of the missile would vary due to the unpredictable frictional xesistance of the cable caused by any movement of the cable relative to the water. Since, as explained above the present invention provides a relatively stationary cable which does not add any significant friction to the system, this problem has been obviated. Thus, reducing the friction of the system to a minimum and providing a truly free-falling temperature probe is of primary concern.

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The application of this concept results in a freely falling body whose velocity is not affected by the cable attached to it since the cable is not dragged through the wa-ter but as a result of being payed out by the missile and by the receiving vehicle re-mains stationary with respect to the water.
In the event that the present apparatus is to be utilized by deploying it from a stationary carrier such as a dock or a stationary ship the second play out spool 34 will not be necessary. Thus the end of the cable 24 may be attached directly to the receiving equipment and the temperature probe dropped straight down into the water. ~he play-out spool 26 located within the housing 12 of the bathythermometer will again provide for a freely falling object. Cable 24, therefore, will not offer any resistance to the water because it will remain stationary relative to the water, thereby providing for a more linear and predictable rate of fall for the temperature probe.
It should be noted that by designing the temperature probe for positive rather than negative buoyancy the system may be adapted to work in reverse. Thus the temperature probe could be released from a submerged location, for example from a sub-marine, and the temperature probe will rise vertically up through the water with the cable 24 being payed out through the rear of the probe.
A significant feature of the apparatus described re-sides in the system which utilizes the information gathered by the expendable probe to enable production of a permanent record showing temperature as a function of depth. Various problems arise because of the fact that the missile deploys a great length of wire during its descent~ Thus, if the ship is moving at a high rate of speed it is desirable that the vertical descent of the probe be as rapid as possible to minimize the length of wire deployed for the sake of accuracy as well as for economic 5~3~3~
reasonsO For example, if copper wire is selected, the effect of the temperature co-efficient of resistivity is significant over the range of temperature encountered by the probe during its descent. Thus, the errors introduced by the varying resistance of the copper wire as the temperature of the water changes, might normally appear as changes in the thermistor resistance, which would introduce errors into the measuring circuits.
Figures 5 to 9 illustrate an embodiment according to the present invention in which this serious drawback is avoided.
In this embodiment, the probe consists of a rear, cone-shaped member 50 including three stabilizing fins 52 ~nd a forward bullet shaped lead weight 54. The rate of descent of the probe is controlled by its manufactured wei~ht and close dimension. Small manufacturing errors cause as~netrical pres-sure gradients which in turn result in a path of descent which is not vertical. Compensation for this error is achieved by off-setting the end portions 53 of fins 52 to cause the probe to ro-tate about its vertical axis. Lead weight 54 includes a central bore 55 in which an elongated tubular sea return electrode is disposed. The thermistor 58 is physically located at the for-ward end of the electrode. An important feature of this embodi-ment is the use o~ two wires 60 and 62 electrically connected to opposite ends of thermistor 58 and physically supported in a suitable manner on an insulation pad 64, mounted in a planar member 66. The wires 60 and 62 are colled around the end of the tubular electrode which extends rearwardly from lead weight 5~. Unlike the embodiment of figure 2, the spool contains no rear retaining plate, and instead, -the two wires are coiled in a conical form -to facilitate deployment o-E the line during des-cent o-E the probe. One of the two wires, for example wire 60 is electrically connected to the sea return electrode for reasons which will become more apparent hereinbelow.

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One of the fins 52 includes an aperture 68. The probe may be stored in a container 70 which includes an aper-ture 74 so that a lanyard pin 72 may be inserted through aper-tures 74 and 68 to secure the probe until deployment. The probe is positioned immediately in front of a stationary wire coil 76 wound around a spool, which includes a rearwardly ex-tending radial flange 79 to engage the end of container 70. A
plurality of connector pins 80 are used to couple the entire assembly to the shipboard electronic equipment. The forward extremity of container 70 is closed by means of a cap 82 and includes a rubber bumper 84 to protect the probeprior to its use.
A two wire system is used to compensate for resistance changes in the wire due to temperature differentials. For practicai purposes, it may be assumed that the probe will en-counter temperatures ranging from thirty to minus two degrees céntrigrade. Because of this wide temperature excursion, the significant change in resistance of the deployed wire would normally be confused with the thermistor changes o~ resistance, producing considerable errors. It is also desirable to compensate the gain characteristics of the system so that the effects of the variation in the thermistor rate of change of resistance with respect to temperature are minimized. This rate may vary by as much as a factor of five over the temperature range encountered.
Fig. 7 illustrates a catapult launching system ~or the invention which is particularly useful for launching the probe from the aft portion of the ship. The catapult comprises a triangular base 200 from which three upwardly extending struts 204, 206 and 208 extend. At the upper intersection of struts 204 and 206 a U shaped yoke 210 is secured. A catapult arm 212 is rotatably supported in yoke 210 by means of a pin 213 suitably journalled in the upstanding legs of the yoke. A cylindrical ~L~503~1 container 214, adapted to hold the probe, is mounted at the other end of arm 212. Arm 212 is secured in a U-shaped bracket 216 at the top of strut 208 by means of a pin 218 passing through suitable apertures in the bracket and arm.
A conventional elastic arm 220 under tension is secured between the free end of arm 212 and -the lower portion of vertical struct 208, so that when pin 218 is removed from bracket 216, arm 212 is free to rotate rapidly in a clockwise direction to thus launch the probe into the water at a position free of the propeller and back wash of the ship.
As shown in Figs. 8 and 8A, the trajectory 226 of the probe when catapulted is sufficient to reach the bow wave 222 insurin~ that the probe will not descend into the prop wash area 224, A boom launching system for deploying the probe into the wa-ter is indicated in Fig. 9. The system consists of a vertical mast 228 and a boom 230 extending transversely there-from. Boom 230 is mounted in a carriage 232 which is movable in a vertical direction on mast 228 by means of a guide 233 and ~0 pulley 234.
A second carriage 235 is disposed on the boom, and carries the canister 70. Carriage 235 may be positioned along the boom by means of wire 236 secured at opposite ends to car-riage 235 and rotatably mounted around pulleys 240 and 241.
Thus, rotation of pulley 241 by means of a crank 238 moves the carriage to the left or right along the boom as desired. A
control string 242 is coupled to the lanyard pin 72 extendin~,;
through the canister 70 and probe, which, when manually pulled, will cause the probe to be deployed into the ocean. Guide line 244 is used to support the free end of the boom. I~e boom launching system of Fig. 9 may be used when circumstances dic-tate deployment of the probe from a side of the ship, in which ~05Q~

case the probe is deployed in-to -the waterin the manner diagram-matically illustrated in Fig. 10, which is self-explanatory.
A third launching system is shown in Fig. 11. The launching system in this case comprises a tube 244 into which the canister 70 provided with a stationary wire coil 76 wound in conical form is placed. Tube 244 is rotatably mounted on upstanding post 246 by means of a pivot member 248 in a conven-tional manner. When the pin 72 is removed from the canister from a point external of the tube 244, the probe is deployed into the bow wave in order to prevent the wire from entering the prop wash area as shown in Fig. 12.
It is not necessary that the probe be manually de-ployed into the water by removal of the lanyard pin 72. An al-ternative system is illustrated in Fig. 13, which shows a pair of wires 249, over which a launch signal is received, connected across a fuse element 250 which close a retainer spring 252 to retain probe 50 within canister 70. When the launch signal is transmitted over wires 249, fuse 250 melts releasing the retainer spring 252 and enabling the probe 50 to be deployed into the water by any of the above described methodsO
If it is desired to use only a single wire, the effect of the variable transmission wire resistance due to temperature changes must be cancelled.
The direct recording of the other properties of the ocean is also within the scope of the invention, for e~ample, the precise velocity of sound at various depths of the ocean which is of critical importance in sonar systems.

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Apparatus for measuring a property of a fluid relative to a given dimension, comprising a sensor probe con-taining therein a quantity of wire to be deployed from said probe when the probe is traversing said dimension, recording means including a record medium connected to said wire for recording signals sent by the sensor probe relative to said property, means for moving a portion of said recording means at a rate substantially related to the rate of movement of said probe, and means for compensating for the change in the rate of movement of said probe due to the deployment of wire therefrom.

2. Apparatus according to claim 1 , wherein said record medium is graduated in said dimension, and said means for compensating comprises increased distance between gradations for increasing dimensions.

3. A bathythermograph system for use from a vehicle comprising: a ballistically shaped hollow plummet which is descendable by its own weight in a body of water at a known rate;
means mounted to and at said plummet for responding to water temperature; at least one electrical wire connected at one end to the temperature responsive means and capable of extending between the plummet and said vehicle; and a portion of said wire being coiled within said plummet and another portion of the wire being coiled for location aboard said vehicle so that upon movement of both the vehicle and the plummet the wire remains substantially motionless in the water, and means on said vehicle whereby water temperature as a function of water depth can be determined or indicated based on electrical data transmitted through said wire which include compensating means for the change in the rate of movement of said plummet to the deployment of wire therefrom.

4. A bathythermograph system as claimed in claim 3 in which said means located aboard said vehicle indicates the temperature of the water as a function of time; and said wire at an opposite end being connected to the indicating means aboard said vehicle.

5. A bathythermograph system as claimed in claim 3 wherein: the temperature responsive means is a thermistor.

6. A bathythermograph system as claimed in claim 3, wherein: a pair of wires are connected at respective ends to the temperature responsive means and extend between the plummet and said vehicle; one of said wires is connected to feed power to said temperature responsive means and the other wire is con-nected to the sensing and indicating means on said vehicle for feeding a signal thereto.

7. A bathythermograph system as claimed in claim 3 wherein: only one wire is connected at one end to the tempera-ture responsive means and is capable of extending between the plummet and said vehicle; and means connected to said indicating means on said vehicle for grounding the latter means to the body of water.

8. A bathythermograph system as claimed in claim 4 wherein: said indicating means aboard said vehicle is programmed to the known rate of descent of the plummet.

9. A bathythermograph system as claimed in claim 8 wherein: the indicating means aboard said vehicle is a strip chart recorder.

10. An apparatus usable with a vehicle for indicating a water condition as a function of water depth comprising: a ballistically shaped hollow plummet which is descendable by its own weight in the water at a known rate; means mounted to and at said plummet for responding to a water condition; at least one electrical wire connected at one end to the water condition responsive means and capable of extending between the plummet and said vehicle; a portion of said wire being wound within said plummet and another portion of the wire being wound for location aboard said vehicle so that upon movement of both the vehicle and the plummet the wire remains substantially motionless in the water so that it is freely extendable as the vehicle and plummet move with respect to one another; means including rate of deployment compensating means adapted to be located aboard said vehicle for sensing the response of the water condition respon-sive means and indicating the water condition as a function of time; and said wire at an opposite end being connected to the sensing and indicating means whereby the water condition as a function of water depth can be determined or indicated based on electrical signals transmitted through said wire.