CA1039081A - Bathythermograph system - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE
The present invention relates to a bathymetry device which enable a determination of water temperature as a function of the depth of the water. The invention includes a ballastically shaped plummet which has a known sinking rate and which is connected by a wire to a vehicle, such as a ship. the wire is coiled within the plummet and is connected at its probe end to an electrical temperature response means such as a thermistor. The wire may also be coiled aboard the ship and may be connected at the ship end to a sensing and indicating means which plots a temperature profile. As the ship and the plummet both move in the water the wire therebetween will remain substantially motionless.

Description

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The present invention relates to a bathythermograph system and more particularly to such a system wherein a wire connected temp-erature responsive device is paid out from a vehicle and is expen-dable after temperature signals are fed to a recording device aboard the vehicle. -Bathythermograph readins of the seas are essential to national defence and oceanographic research. These readings provide a tem-~ . . .
perature versus depth curve which indicates the location of thermo-clines as well as positive and negative thermal gradients within -the water. This enables operational navy elements to determine the range capabilities of their sonar equipment and the likely ; location of enemy submarines. Such information also affords a basis for predicting weather conditions and fish migration. -The bathythermographic art has remained static for many years.
There is a critical need for an economical system which can be easily and quickly operated so that a wider coverage of temperature conditions within the oceans can be obtained. The instrument which , has been used for many years for bathythermographic readings is a ' self contained device which includes a water depth sensing means ' 20 and a water temperature sensing means. These conditions are indic-ated on a smoked or gold plated glass which is also part of the instrument. This instrument is lowered into the water from the starboard or port quarter of a ship by a cable which is coiled on a motor driven drum. When the bathythermograph instrument has , 25 reached the desired depth it is wound back to the ship and the gold ' plated glass is removed for recording purposes. The use of this ,;
instrument has been particularly cumbersome for our operational Navy elements since the ship must be slowed to a speed below 20 knots to allow the instrument to descend to a reasonable depth.

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Further, the paying out and reeling in of the cable as well as the plotting of the indications from the gold plated glass on readable ' ` -1-,. . : : . : ;: :
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chart paper have been too time consuming. The present bathythermo-graph system, as described hereinafter, provides reliable and quickly obtainable temperature versus depth i.ndications of the ocean without the necessity of slowing the ship below a particular speed.
The present bathythermograph system includes a plummet which is descendable in the ocean at a known rate; a means such as a `~
thermistor .:

-la-~39Q81 mounted to the plummet for responding to water temperature; a very fine wire connected at one end to the thermistor and capable of extending between the plummet and a ship; and means located aboard the ship for sensing the response of the temperature response means and indicating water temperature as a function of time. The wire is coiled at some portion along its length so that the plummet is freely extended from the ship as the plummet and ship move with respect to one another. The time indication of the sensing and indicating means can be easily correlated with the known rate of descent of the piummet so that water temperature versus water depth can be easily determined or indicated. When a reading is desired ~
the plummet is thrown overboard from the ship. The plummet will `;
descend freely within the water since the attached wire is freely èxtended from the coil ànd will exert substantially no resisting force thereon. As the plummet descends in the water a temperature signal is transmitted to the sensing and indicating means aboard the ship via the wire therebetween. The plummet and temperature i responsive means as well as the wire are so inexpensive that they can be expended after the temperature reading is obtained.
An object of the present invention is to overcome all of the aforementioned disadvantages or prior art bathythermograph systems, devices or methods.
Another object is to provide a bathythermograph system which can obtain information without slowing the ship below a particular speed.
A further object is to provide a bathythermograph system which will indicate temperature versus depth information aboard a vehicle while the system is in operation in the water.
Still another object is to provide a bathythermograph system which includes an expendable portion which is responsive to water temperature withln a body of water.

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Yet another object is to provide a bathythermograph sy~tem which is reliable, economical and which can be easily operated to quickly obtain the desired information.
Still a further cbject is t~ pr~vide an ec~n~mical and reliable -2a-:. . - :, . -. ::~ ': ` '`' : .:' -1~)3908~
apparatus which will indicate a water condition as a function of water depth.
Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying ~ -drawing wherein:
Figure 1 is a view of the present bathythermograph system in operation from a ship;
Figure 2 is a schematic illustration of one embodiment of the bathythermograph system with portions thereof shown in cross section;
Figure 3 is an enlarged view taken along plane III-III of Figure 2;
Figure 4 is a schematic illustration of another embodiment of the present invention with a portion thereof shown in cross section;
and Figure 5 is an enlarged view taken along plane V-V of Figure 4.
Referring now to the drawing wherein like reference numerals designate like or similar parts throughout the several views there is shown in Figure 2 a bathythermograph system 10. The bathythermo-graph system includes a probe or plummet 12 and mounted to the plummet is a means for responding to water temperature such as a thermistor 14. Located aboard a vehicle, such as the ship 16, is ; a means for sensing the response of the temperature response means 14 and indicating water temperature as a function of time. This ., sensing and indicating means may be a strip chart recorder 18 as shown in Figure 2. The strip chart recorder 18 is connected to the thermistor 14 by one lead of a very fine double wire 20 which is capable of feeding a temperature signal from the thermistor 14 to the strip chart recorder 18. As will be described more fully here-inafter the double wire 20 is wound into at least one coil so thatthe plummet 12 will be payed out from the ship 16 with substantially no resistance.

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As shown in Figure 2, the plummet 12 may be projectile or bomb shaped with nose and tail ends 22 and 24 respectively. The plummet 12 is constructed heavier in its nose portion so that it will descend in the water with its nose 22 always in a downward position. The weighted and streamlined configuration of the plummet 12 will enable accurate predictions of the -3a-1~3~
r~te ~,f descent of th~ plummet within t1i~ water, the purpose of such predic-tion6 to be more fully explained hereinafterc If desired, the plummet may be provided with fins 26 along its rear portion for further stabilizing its descent within the water.
The plummet 12 may be provided with a rear chamber 28 which will aid in making the plummet nose heavy as well as providing a space for winding the very fine double wire 20. A longitudinal central passageway 30 may extend -~
from the nose 22 to the chamber 28. A pair of diametrically opposite trans-verse passAgeways 32 may communicate the longitudinal passageway 30 with the water environment outside the plummet. The passageways 30 and 32 which may be circular in shape, will allow sea water to enter the pl~mmet nose end 22 and exit transversely through the passageways 32 as the plummet descends within the water. As shown in Figure 2, the thermistor 14 may be mounted to the plummet 12 within the longitudinal passageway 30. The longitudlnal passageway 30 may have a pair of spaced apart depressions 33 for receiving the terminal ends of the thermistor 14 and the double wire 20. An insulative bonding material, such as epoxy resin, is disposed within each depression to form a ,~
plug 34 which bonds a terminal end of the thermistor 14 with a respective e~d of the double wire 20. In this manner the thermistor and dGuble wire are electrically insulated from the water environment.
As shown in Figure 3, the double wire 20 has a pair of conduct- -~
ing elements which may be bonded within an integral insulative covering such as '~ylar"~ or polyethylene. It is highly desirable that the double wire 20 be very fine in size. Each wire may be rated in size between a number 28 and a number 34 wire. In order to enable the plummet to be freely descendable within the water the double wire 20 is wound into a coil 36 within the plummet chamber 28.
The coil 36 may be wound similar to a ball of twine with the wire being payable from the center of the coil. Such an arrangement will i 30 exert practically no resistance on the plummet as it descends within the water.
The bottom end of the coil may be bonded to the bottom of the - 4 _ `I ~ A Trademark for a polytetrafluoroethylene of the I Dupont Company : . . .

1~;)39081 chamber 28 by any suitable cemen-ting material. If desired, the wire 20 may be wound on a mandrel or spool (not shown) which may be cylindrical, or tapered toward the direction in which the wire is payed out. If the wire 20 is wound on a spool it would be payed out from the exterior of the coil and it would be advisable to taper the spool toward the direction in which the wire is payed out so that there is minimum resistance between the wire during the paying out action.
The double wire Z0 may extend upwardly from the coil 36 through a small central opening 38 in the tail end 24 of the plummet. The double wire 20 at the bottom of the coil 36 may extend downwardly through the longi.tudinal channel 30 for connection to the thermistor ends within the insulative plugs 34. Accordingly, as the plummet 12 descends within the water the double wire will be freely payed out from the coil 36 so that substantially no resistance will be offered to the descent of the plummet.
The double wire 20 may also be wound into another coil 40 aboard the ship, this coil being wound simi].arly to the coil 36 within the ~;
plummet 12. The coil 40 may be disposed within a boxlike container 42 which has an opening 44 for receiving the payed out end of the double wi.re 20 f`rom the coil 40. The container 42 has another opening 46 for receiving one of the double wires, this wire feeding the temperature signal to the strip chart recorder 18. The other one of the double wires may be connected to a terminal 48 which is mounted in the top of the container 42. The terminal 48 is adapted to be connected to a p~wer source (not shown). Accordingly, power is applied to one side of the thermistor 14 and a temperature signal is taken off of the other side of the thermistor due to temperature changes of the thermistor as it descends within the water. As shown in Figure 2, an amplifier 50 may be connected between the strip chart recorder 18 and the thermistor 14 for .,. ~

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:: ,. , .,, ., " ,, , ~39Q~31 increasing the temperature signal.
lf desired, a buoy 52 may be provided for floating a section of -the double wire at the surface of the water. As shown in Figure 2, the double 20 is fixed to the buoy 52 intermediate the wire ends by a pair of plugs 54 which sealably extend through walls of the buoy 52, one of the plugs -5a-, ~ .

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projecting through a sidewall of the buoy and the other plug 54 projecting through a bottom wall thereof. As shown in Figure 3, the plug 54 may be cylindrical in shape and longitudinally divided into two halves 56 and 58. The cylindrical halves 56 and 58 may be constructed of a resilient material such as rubber so that when they are force fitted through the buoy wall the double wire 20 is held in tight engagement therebetween. The buoy 52 may be provided with a valve 60 for inflation and deflation purposes.
The strip chart recorder 18 senses the temperature signal from the thermistor 14 and indicates water temperature on a chart 62 by a stylus 64. The chart 62 rolls at a known rate of speed so that the curve plotted on the chart 62 by the stylus 64 indicates water temperature as a function of time. The chart 62 is shown with a series of markings 68 along one of its longitudinal edges to indicate the depth of the water. As stated previously the plummet 12 is configured so that the rate of descent of the plummet within the water can be accurately determined. This rate of descent can be determined by an actual test drop of the plummet within the water.
The indications 68 may be marked off in feet at appropriate intervals which are correlated to the known rate of descent of the plummet 12 so that the chart 62 will indicate directly temperature versus depth of the water. As an alternative the strip chart recorder 18 may have a variable speed drive means for rotating the chart 62. In this manner the speed of movement of the chart 62 can be adjusted to correlate the kno~n rate of descent of the plummet 12 with particular spaced markings of any chart. If desired, a switch 70 may be connected between the strip chart recorder 18 and a power source (not shown) for the purpose of starting the strip chart recorder at a selected time.
Another embodiment of the present invention is shown in Figure 4.
This embodiment differs from the other embodiment in that a single . , ~

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wire 72 is utilized rather than a double wire. With this arrange-ment the strip chart recorder 18 receives -the temperature signal from the thermistor 14 by sea return. The single wire 72 is connected to one end of the thermistor 14 within the insulative plug 34. The other end of the thermistor 14 may be connected directly to the wall of the longitudinal passageway 30 so as .~

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~39~81 to be exposed to the sea water environment. The amplifier 50 is grounded to the ship at a terminal 74. Alternatively the amplifier could be connected to a sea buoy (not shown) which extends from the ship for the purpose of` grounding the amplifier to the sea environment. The ground connection will pick up the temperature signal from the exposed terminal end of the thermistor 14 and feed '~-it to the strip chart recorder 18 for indicating purposes as described hereinabove.
In the operation of either embodiment the plummet 12 may be manually thrown from the ship 16. When the plummet 12 strikes the surface of the water the switch 70 may be actuated to feed power to the strip chart recorder 18 and start the chart 62 in movement from a zero depth indication. If the buoy 52 is employed it will be thrown into the water simultaneously with the plummet 12. As the plummet 12 and the buoy 52 are thrown from the ship the wire is freely payed out from the shipboard coil 40. The relative movement between the plummet 12 and the ship 16, due to plummet descent and ship speed, has essentially no effect on the descent of the plummet 12 because of the free paying out action of the coils 36 and 40.
IN essence, the plummet 12 is descending within the water as if there was no physical connection between the plummet and the moving .
ship. Yet a continuous temperature signal is being fed from the thermistor 14 back to equipment aboard the ship.
It is to be noted that a means for responding to a water con-,' 25 dition other than temperature could be mounted to the plummet 12.
: For instance, a means for responding to water conductivity or light intensity could be mounted to the plummet 12 in which case water conductivity or light as a function of water depth would be indicated . aboard the vehicle. Accordingly, the broad scope of the invention is not to be confined to a means for responding to water temperature .~

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I:)ut st-~ou:lcl t~c con~ rl.led to -inc:lude all meLlrls which respond -to some wilter cotl~litiorl. :Lt mily be desi.rclble to mount several water concl.itiorl re.c;ponclers to a single plumrrle-t in which case several w;ltcr cc)rldit:iorl.s would t~e :ind:ic~-ted as .1 furlction of depth.
I:n some inst.-lllces it rnay t)e desirable to condition the resis-l:arlce si.gnill 1C)39~
at the p]ummet 12 before it is fed to the ship 16. For instance, an oscillator (not shown) could be connected to the output terminal of the therrnistor 14 within the passageway 30 just above ~he thermi-stor. A small power pack could likewise be mounted to the plummet 12 for driving the oscillator or alternatively, the oscillator could be driven by power from the ship over an additional wire.
The oscillator frequency would be controlled by the resistance of the thermistor 14 and this frequency would be demodulated by a demodulator (not shown) aboard the ship. The demodulated signal would then be utilized by well known state-of-the-art means to operate the strip chart recorder 18.
It is now apparent that the present invention provides a novel approach to obtaining bathythermograph readings. The present invention is very economical to construct and yet will provide reliable information. The ship 16 may continue at its normal rate of speed without slowing down to make bathythermograph readings and upon completion of the readings the plummet 12, the buoy 52 and the payed out wire may be severed from the ship and expended.

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Claims (2)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE
IS CLAIMED ARE DEFINED AS FOLLOWS:

1. 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; 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;
a buoy, with said wire being fixed to the buoy intermediate the wire ends; and means on said vehicle whereby water temperature as a function of water depth can be determined or indicated based on electrical data trans-mitted through said wire which include compensating means for the change in the rate of movement of said plummet to the deployment of wire therefrom.

2. A bathythermograph system as defined in claim 1, wherein the temperature responsive means is a thermistor, and wherein the plummet is elongated and has a nose and tail end, said plummet also having a longitudinal passageway extending from the nose end and a pair of diametrically opposite transverse passageways which communicate with the longitudinal passageway and the environment outside said plummet; and said thermistor being mounted to the plummet within said longi-tudinal passageway closer to the nose than the place where said pair of diametrically opposite transverse passageways communicate with said longitudinal passageway.