Fig. k. Detachable connector from bead to harness: (a) leads, (b) neoprene cap, 



(c) neoprene body, (d) gold-plate brass male connector, (e) gold-plate brass 

 female connector, (f) neoprene body, (g) neoprene cap and (h) lead to harness. 



A watertight connection between the leads and 

 the harness is important because this is the 

 most probable location of water leakage. The 

 connectors, consisting of brass plugs crimped on 

 the end of each lead and then soldered, are 

 inserted in special neoprene connecting plugs 

 that fit together without air space as the brass 

 connections are made. A watertight neoprene 

 sleeve slides over the wire leads and the con- 

 nected plug. Any defective thermistor can easily 

 be replaced by unplugging the unit and inserting 

 a new one. 



The leads extending from the encapsulated 

 beads (F, Fig. 3) developed leaks after prolonged 

 use. The addition of a silicone rubber cap 

 (E, Fig. 3) provided a satisfactory seal. 



Another important improvement was made in the 

 connectors which now consist of tightfitting 

 neoprene sleeves so constructed that there is no 

 air space to permit leakage (Fig. k) . These con- 

 nectors, manufactured by Electro-Oceanics, have 

 proved watertight through long immersion. 



Harness 



The present harness, manufactured by the 

 Spectra Strip Wire and Cable Corporation is made 

 of Wo. 22 19-strand copper wire. It is first 

 covered with a 0.008-inch layer of polyethylene 

 to prevent water from getting between copper and 

 insulation. Then a 0. 008-inch layer of poly- 

 vinyl chloride is applied to reduce abrasion in 

 the links. Wine color-coded wires are cemented 

 together with polyvinyl to form a ribbon. Thir- 

 teen of these ribbons make up the harness, a 

 total of 117 leads, which is preformed in a zig- 

 zag fashion, taped at intervals and laid in the 

 channel of the chain (Fig . 5 ) . All 117 leads do 

 not go the full length of the chain but are 

 sealed off at different distances along the har- 

 ness so that only 27 leads reach the chain end. 



The 3 1 *- thermistor beads use 2 leads each and 

 3 leads service the pressure element. The ther- 

 mistor chain thus requires a total of 71 leads, 

 leaving a number of spares . The inner leads of 

 the harness are normally used as conductors since 

 they are less susceptible to chafing and leaks. 



An initial difficulty was the lack of water- 

 tight integrity in the electrical harness. Points 

 of vibration and friction in the bundle of wires, 

 connections of the thermistors to leads, connec- 

 tion of leads to the detachable plugs and the 

 plugs themselves all proved susceptible to leakage. 

 Connections at the greatest depth were the most 

 prone to leak. 



The first attempt to prevent leakage utilized 

 a heavy rubber jacket over leads and vulcanized 

 connectors. This proved too stiff to spread 

 properly as the chain passed over the sheave on 

 the fantail and to loop back into the channels in 

 the links when the chain hung vertically. 



ELECTROWIC COMPOWEWTS 



Contouring Temperature Recorder 



The contouring temperature recorder, built by 

 the Scientific Services Laboratories, is the 

 heart of the unit, taking information from the 

 thermistors in the chain towed behind the ship 

 and plotting the vertical distribution of tempera- 

 ture as a continuous record (Fig. 6). Each iso- 

 therm (line of constant temperature) is displayed 

 as a depth profile similar to that made by a 

 depth recorder and the complete record gives a 

 2 dimensional representation of the thermal struc- 

 ture of the sea. Since the thermistors are 

 scanned from top to bottom the vertical scale of 

 the record represents the length of the chain in 

 the water. 



The thermistors are placed at even intervals 

 on the chain. Usually 3^ measuring thermistors, 

 spaced at 27-foot intervals, are programmed. As 

 these are towed through the water the recorder 

 interpolates and prints on the paper roll the con- 

 tours of the various isothermal surfaces where the 

 horizontal scale represents either time or dis- 

 tance and the vertical scale depth. Since the 

 ship speed at 6 knots is believed to be several 

 times faster than internal waves, the effects 

 depicted are primarily spatial. Normally tempera- 

 ture increases toward the surface. However, in 

 case of temperature inversions, where warm water 

 underlies cold, the positive temperature gradient 

 area may be shaded on the record for identification. 



55 



