that will be photographed each hour (table 

 M-1). 



The A-101 meter is shipped with six inter- 

 changeable cams with 1, 2, 3, -1, 6, or 12 lobes. 

 The extra cams and a cam puller are kept with 

 the meter. They are located on the lower side of 

 the inclinometer platform. 



Table Ml. Recording time versus recording interval 

 for 100 feet of film (from table 3.2 TM 66-61) 



Minutes Recording 



Number of lobes between time 



on cam data cycles (days) 



1 _ 60 207. 5 



2 30 103.7 



3 " " 20 69. 2 



4 15 51.9 



12::::::::::::^: 5 17.3 



At continuous operation 83hrs. 



To install the cam for the desired data cycle 

 proceed as follows : 



Step 1. Kemove the two screws on the face of 

 the timer, then remove the cam screw from the 

 1 -hour shaft. 



Step 2. Place the jaws of the cam puller be- 

 hind the cam and slowly turn the thumbscrew 

 in a clockwise direction until the cam is 

 removed. 



Step 3. Seat the desired cam on the shaft and 

 replace the cam screw and the timer cover. 



5. Checking data light row platen display. — 

 Current data are recorded on film by photo- 

 graphing the data light row platen in the field of 

 view beneath the camera lens. Each time the 

 meter pulses, lights flash at the various meter 

 components (rotor, vane, compass, inclinometer, 

 clock, and chronometer) , the light is transmitted 

 to the field of view by optical fibers, and the 

 field of view is photographed. The resulting 

 film record (fig. M-15) is a series of spots that 

 can be decoded and processed into current speed 

 and direction. The optical fibers in the field of 

 \iew should be checked before each operation to 

 determine that all components are functioning 

 properly and that the light is being transmitted 

 to the field of view. 



Step 1. Press test button to check light bulbs 

 at compass, vane, and timer. Lights should re- 

 main on while the test button is depressed. 



Step. 2. Set toggle switch to Continuous. 

 Remove On-Off switch magnet. 



Step. 3. Clieck to see that each optical fiber 

 lights in the data light row platen. Using the 

 following procedures and checking from right 

 to left, with instrument serial number on left, 

 indicate on the check out record that the data 

 light row platen was inspected. 



Current meter model A-101 has 25 data lights 

 in the data light row platen. 



Change 1—1970 



No. 1 is a continuous channel ; it should 

 light during each 5-second pulse for approx- 

 imately 2 to 3 seconds. 



No. 2 is the inclinometer channel. Tilt the 

 meter to check the channel. During one com- 

 plete film-advance cycle (1 minute) , the chan- 

 nel should i^ulse once for each 5° inclination 

 of the meter, e.g., if the meter is upright, the 

 channel will not light. If meter is tilted 10°, 

 two pulses will light in channel 2. Zero to 35° 

 meter inclination can be recorded. 



Nos. 3 through 10 are the speed channels. 

 Spin the rotor by hand altering the speed, 

 and check to see that each of the eight chan- 

 nels light as the number of revolutions of 

 the rotor is totaled each 5 seconds. It is not 

 necessary to check rotor revolution versus 

 lighted channels. 



Nos. 11 through 17 are the vane-direction 

 channels. Move the vane through 360° and ob- 

 serve whether each of the vane channels 

 transmits light. These light spots and blanks 

 are coded in gray binary. 



Nos. 18 through 24 are the compass chan- 

 nels. Swing the compass 360° using the on- 

 off s^vitch magnet. Observe whether each of 

 the channels transmit light spots and blanks. 

 These are coded in gray binary. 



No. 25 is the reference channel. It should 

 light once every 5 seconds for 10 jjulses and 

 then not light for two jDulses. 



Instrument serial number. This number 

 should light on the second pulse of a data cycle. 



At each pulse, the sound of the camera drive 

 motor should be audible. For 10 pulses, all chan- 

 nels could light up, but for the last two pulses, 

 of a data cycle only channel 1 should light. 



Step 4. If any of the optical fibers fail to 

 transmit light, check the light-pipe connection 

 at the source and at the data light row platen; 

 next replace the complete instrument module 

 involved, i.e., printed circuit, clock, compass, 

 vane follower, or inclinometer. 



Step 5. If any of the channels light improper- 

 ly, replace the malfunctioning module involved. 



6. Loading film. — Current data are recorded 

 photographically on 16-mm. Kodak, Double-X 

 Panchromatic, negative, movie film. A 100-foot 

 roll of film will record 4,500 sets of data. A new 

 roll of film should be loaded in the camera of 

 the meter for each current meter plant. 



Step 1. Remove camera from the instiiiment 

 assembly (fig. M-13) by loosening two thumb- 

 screws on the uppei' side of the inclinometer 

 platform and two thumbscrews on the under 

 side of the camera platfonn. 



Step 2. Remove camera case cover, 2 screws 

 hold cover in, place, then remove the O-ring 

 drive belt. See figure M-16. 



Step 3. Place film supply reel on shaft (A), 

 pull out about 1 foot of film, and thread it 



M-13 



355-756 O - 70 - 



