DATA RECORDING DEVICE FOR UNDERWATER INSTRUMENTATION 
by JAY W. HARFORD, Engineer 
and EARL D, VAN REENAN, Senior Geophysicist 
Edgerton, Germeshausen&Grier, Inc. 
Boston, Massachusetts 
ABSTRACT 
Modified versions of a standard EG&G 
underwater camera are described with necessary 
circuitry to use as lapse-time data cameras, 
The standard camera can be modified to have one 
or two data chambers. The dual chamber data 
camera will take 4,000 data pictures sequentially 
in six pairs to handle up to 12 sensing instru- 
ments. The data camera can act as a versatile 
nucleus of an underwater instrument package for 
the recording of various oceanographic variables. 
I INTRODUCTION 
Recording of oceanographic variables 
in situ requires a reliable recording device 
which can record sequentially over extended 
periods of time while in an oceanographic envi- 
ronment. This paper describes a simple and com- 
patible data recording system which can serve as 
a nucleus instrument package for the read out of 
several measuring instruments. The basic re- 
corder consists of a data camera which is readily 
adaptable for many uses. This data camera can 
take data pictures from one end or both ends 
depending on the number of sensing elements used 
and type of meters required. 
II DESCRIPTION 
A. Single Ended Data Camera 
The basic single ended data camera is 
a special modification of the EG&G Model 200 
Underwater Camera. The camera is contained in a 
high strength stainless steel housing designed to 
withstand 20,000 psi. The read out meters are 
placed on the end cap. The data camera film 
capacity is 100 feet of 35 mm film on a daylight 
loading spool. This gives 2,000 frames per roll 
with 15 millimeters per frame. The data lens is 
a Wollensak Cine-Raptar 13 millimeter focal 
length, £2.5. The light source consists of an 
internal tungsten bulb. Automatic timing con- 
trol can be provided by a 6 volt d-c cam type 
timer which is available in various time 
intervals. 
B. Dual Ended Data Camera 
The dual ended data camera is an 
extension of the single ended data camera with 
data pictures taken at both ends. This provides 
greater meter area and more efficient utilization 
of film space. The dual ended data camera will 
take 4,000 data pictures per 100 foot roll. The 
camera lenses on either end of this camera are 
staggered to give a double row of data pictures. 
A maximum of 12 separate instruments can be 
sequentially recorded by this data camera. It is 
possible to use 2 or more meters with different 
ranges to reduce the problem of having the 
measuring instruments compatible with the read 
out. A clock, pressure gauge, and data card can 
be provided on one end of the camera if desired. 
The dual ended camera with a single meter is 
shown in Figure l. 
Fig. 1 Data Camera Mechanism 
