Calibration Tank 
The calibration tank is made with an inner lining 
of ¥-inch lucite, measuring 28 by 232 by 30 inches, 
backed by an aluminum foil for radiation insulation 
(fig. 4). Further heat insulation is provided by a 42- 
inch layer of tar-coated cork-board surrounding the 
inner lucite shell on all sides and at the top and 
bottom. This inner tank of lucite is supported evenly 
along its bottom on a grid of 2 x 4’s to prevent 
deformation and possible rupture by the weight of 
ste areeee, i - 
chip a | 
A. RACK BEFORE REVERSAL 
water (approximately 600 Ib) it contains when in 
operation. The outer shell is of Y2-inch plywood re- 
inforced at all angles by strength members. 
The whole tank is supported at the corners by 
tubular aluminum uprights, 3 inches in diameter with 
Y inch wall thickness. These are equipped with screw- 
adjustable feet for levelling purposes and extend 
to a height of 8 feet above the floor. Mounted on 
the top of each upright is a pulley assembly for the 
wire that raises and lowers the lid. 
Figure 4. Calibration tank, shown (A) before reversal of rack, (B) during reversal 
of rack, and (C) with rack removed. 
B. RACK BEING REVERSED 
