predetermined period of from 5 minutes to 113 minutes, it is merely necessary 

 to turn the "MANUAL SET TIMER" to the desired time interval; the recorder will 

 immediately start to record and at the end of this interval will automatically 

 return to the automatic cyclic operation. 



The supply and takeup spools for the chart paper are mounted in a 

 single removable magazine as shown at the bottom of Figure 3- One spool is 

 sufficient for 50 days automatic operation at the lower chart speed. Differ- 

 ent chart speeds could readily be obtained by a change of gear ratios. The 

 entire unit may be mounted in a standard rack, or it may be shock-mounted. 



The over-all sensitivities of the several channels are given in 

 Table 1 . 



TABLE 1 



Sensitivity of the Several Channels of 

 TMB Automatic Ship's Motion Recorder 



Channel 



Quantity 

 Measured 



Range on 



Attenuator 



XI 



(full scale) 



Range on 



Attenuator 



X3 



(full scale) 



Sensitivity 



millivolts 

 per inch 

 deflection 



Over-all Sensi- 

 tivity of Trans- 

 ducer and Re- 

 corder 



(Attenuator XI ) 



Heave 

 Acceleration 



Roll Accel- 

 eration 



Pitch Ac- 

 celeration 



Roll Angle 



Pitch Angle 



±1 rad/sec £ 

 + p- rad/sec' 



ky 

 15° 



±V3 g 



+-? rad/sec 2 



+ Z" rad/sec 2 



15' 

 5' 



1 inch/g* 



2 inches/g* or 



1 inch/rad/sec 2 ** 



U inches/g* or 



2 in/rad/sec 2 ** 



*g is the acceleration of gravity. 

 **Sensitivity of 2 linear pickups 16.1 feet apart, wired in series opposition. 



THE TRANSDUCERS 



The recorder may be used to record the voltage output of a variety 

 of transducers provided the frequency of this voltage is the same as that re- 

 quired to drive the two-phase pen motors. For our purpose, however, we will 

 discuss the operation of the particular transducers that have been used to de- 

 termine the heaving, rolling, and pitching accelerations as well as the roll- 

 ing and pitching angles of the ship. 



