m> COVER SCREWS 



CAMERA (COVER SIDE) 



DRIVE GEAR 



0-RING DRIVE BELT 



CAMERA (PULLEY SIDE) 



CAMERA WITH FILM LOADED, COVER REMOVED 



Figure M-16. Geodyne current meter camera 

 model A-101, 



an(i remove plastic bag from desiccant on 

 camera cover. 



Step 4. Remove O-rings from grooves in up- 

 per and lower end caps. Wipe rings clean of old 

 silicone grease and inspect for scratches, cuts, 

 or breaks. Replace if at all questionable. 



Step 5. Clean O-ring grooves of end caps and 

 lubricate and then replace O-rings. 



Step 6. Inspect and clean ends of pressure- 

 case cylinder; then, lower it down over the in- 

 stnunent. Check for proper seating of tlie 

 cylinder on the lower end cap. 



Step 7. Next, line up tie rods with holes in 

 lower end cap, and lower the uj^per-cap as- 

 sembly onto the pressure-case cylinder. Seat the 

 end cap carefully and replace fiber washere, flat 

 washei-s, lock washers, and nuts to the tie rods. 



Step 8. With vise-grip pliers and open-end 

 box or torque wrench, tighten the rod nuts to 

 10 to 15 foot-pounds, making sure that the rods 

 are straight with meter axis. 



Step 9. Tape vane and rotor to prevent their 

 turning. Replace the On-Off switch magnet to 

 inactivate the current meter. 



8. Launching or planting current meter. — 

 The (WHOI) (Richardson) current meters 

 liave been used successfully by Naval Oceano- 

 grapliic Office oceanograpliers in both deep 

 water and shallow water. Figure M-17 shows the 

 technique used to measure currents in areas 

 where water depths permit di\ers to plant the 



Change 1—1970 



meters on bottom-mounted tripods. This method 

 has been extremely satisfactory because divers 

 are able to inspect the meters from time to time 

 to insure tliat the rotor and vane are function- 

 ing, to remove any organisms that may be foul- 

 ing tlie meter, and to listen with a stethoscope to 

 insure that the internal mechanism is operating. 

 In deeper waters, the most satisfactory method 

 of measuring currents at multiple depths with 

 the meters is the mooring array shown in figure 

 M-18. 



Nylon lines (^le-inch) are shackled to the 

 meters, and anchor-first and free-fall techniques 

 both have been used successfully in planting 

 current meter arrays. 



The most frequent causes of instrument oper- 

 ational failure are : 



ImprojDerly loaded film. 

 Failure to remove lens cap. 

 Improperly seated pressure case on O-rings. 

 Failure to remove the tape from vane and 



rotor. 

 Failure to remove the On-Off switch 



magnet. 

 Binding of gear drive or movement of 



camera. 



NOTE: Always use the check-out sheet and 

 avoid failures of careless oversight or neglect. 



9. Opening the meter to obtain current data 

 record. — 



Step 1. As soon as the meter has been 

 brought aboard the survey vessel, tape the vane 

 and rotor, and open the meter following pro- 

 cedures outlined in steps 1, 2, 3, and 4 of para- 

 grajjh 2. NOTE: Pei-mit meter to come to 

 ambient temperature before opening, or rinse 

 with warm water; otherwise, condensation may 

 damage the film. 



Step 2. Remove the lens cover from the place 

 where it was taped beneath the compass and 

 cover the camera lens. 



Step 3. Remove the camera case from the 

 assembly by removing the four thumbscrews 

 that hold camera in place. 



Step 4. Rotate pulley B counterclockwise 

 until there is no drag. The film is then all on 

 the takeujj spool. 



Step 5. Ojjen the camera case, grasp the 

 outer edges of the takeup reel, apply thumb 

 pressure to the center of shaft (A), and snap 

 out the reel. 



NOTE: It is not necessary to annotate the 

 instnnnent serial number on the film since the 

 number is photographed following each data 

 block. 



Step 6. Put exposed film in film can. Seal 

 can with tape and jilace in film box. Label film 

 can and box clearly with instrument serial num- 

 ber, recording location, launching and retrieval 

 dates and time, and project or operation identi- 

 fying numbers. Developed films are processed 



M-15 



