T.^E RECORDER 



The recorder used \-rith tiie gage is a General Electric Photoelectric 

 Recorder, Catalogue 32G120. It consists of two elements; (l) a sensing 

 element which receives the signal from the pressure head, and (2) a record- 

 ing element which drives a pen and chart in such a manner as to produce 

 a pen-and-ink record of the pressure changes at the pressure head. There 

 are several types of sensing elements which can be used with the recorder, 

 however, only one is suitable for use with the gage as designed and con- 

 structed. The suitable sensing element is a Catalogue Type 32C2149/G37 

 Galvanometer Fluxmeter. Complete instructions for the operation and 

 maintenance of the recorder are given in the General Electric instruction 

 book. 



For shipping purposes the fluxraeters have been blocked to prevent 

 damage and should be freed in the following manner: 



a. Open recorder case, l^ress down the two paper drive carriage 

 retainer arms. (Parts A, Figure 3). Allow paper drive carriage to 

 swing down. 



b. Unscrew the thumb screws shown by arrows in Figure ij.. Pull 

 out Fluxmeter galvanometer mounting plate. 



c. Unscrew fluxmeter galvanometer element retaining screw 

 (shown by arrow on Figure 5). Carefully tilt the galvanometer mounting 

 plate so that bottom section of the galvanometer element is outward, 



and slowly pull on the bottom section until the galvanometer is withdrawn 

 from the case. 



d„ Using ivory-tipped tweezers, carefully remove the two paper 

 blocks holding the galvanometer coil in place. (Figure 6). 



The pressure head is connected to the recorder by placing the white 

 wire of the cable around the vftiite binding post and the black wire around 

 the black binding post marked "Fluxmeter" on the back of the recorder. 



THE RECORD 



The records obtained from any run made at pcirae -Selected depth are 

 subject to corrections in order that adjustments for wave period and 

 height of water above the pressure head can be made. The wave period 

 (elapsed time from crest to crestj can be taken directly from the chart 

 paper, since (with 60 cycle power) the speed of the paper travel is 

 known to be 6 inches per minute or 0.1 inch per second. After the period 

 is determined for the individual wave, a correction based on the wave 

 period and height of water over the pressure head is made according to 

 the approximate formula: 



"d = ^% °^ \ = Hd 



