(Sanitized) DIGITIZER INTERFEROMETER MODIFICATIONS APPLICABLE TO MODEL 405B CHIP COMPARATOR

• Document Type: CREST
• Collection: NGA Records (Formerly NIMA)
• Document Number (FOIA) /ESDN (CREST): CIA-RDP78B04747A001500030038-2
• Release Decision: RIPPUB
• Original Classification: C
• Document Page Count: 3
• Document Creation Date: December 28, 2016
• Document Release Date: May 6, 2003
• Sequence Number: 38
• Publication Date: September 9, 1966
• Content Type: LETTER

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DECLASS REVIEW by NIMA/DOD
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R E G I S T E R E D
Colonel, USr",F
Assistant for Plans and Developn t, NPIC
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Subj ec t:
Reference: a)
Digitizer Interferometer
Modifications Applicable to Model 405B
Chip Conmarator
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b)
9 September 1966
letter
dated 8 July 1966
letter :*1237
w t n July t^66
In accordance with our letter, reference (b), we stated
that Our te-L on po si1,_! 1e to improve the sta-
bility of the inter. feror cte:? s a to be cOA l?:)letec at the end
of August. We also stated t hac we would report to you of our
results at that time. We havr,. completed our ~,esL prorrarn and
achieved Li;.{_ resulte e{pt:cted. A summary of our testing and
results are given below.
"TEST PROGRAM
A) Temperature Regulation
Brief study was given to temperature regulation by
means of a proportional controller purchased from,,-ii 25X1A
No serious problems showed up initially, but further
consideration indicated that illumination control would be
more satisfactory. Control of illumination would regulate
temperature to compensate for the variations of RF generator
output.
B) Illumination Control
A control circuit was breadboarded and temperature
checked on the bench with a heat gun. The circuit was designed
for use with a Clairex type CL705 photoconductive cell. ;Al-
though the water was heated above room ambient, the merdury
lamp was being cooled below the temperature at which it would
operate in air with no water circulation. The circuit actuated
a relay providing "on-off" control to a heater in the water
tank of the Interferometer,
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9 September 1966
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With the above se in the temperate e ntrolied
rte, numerous variables we stigated. These included
tank insulation, a fan to coolie tank, a stirrer, various
types of pumps, water flow rates, location of the pump inlet,
and instating tubing for the water tubing.
TEST REM UM
The most satisfactory operation was obtained with
the exit temnperature from the lamp coil at 108 degrees F. Tem-
perature varied approximately t 1 degree F. At this exit tem-
perature the average water t.k temperature was 107 degrees F
in a room ambient of 72 degrs F. Cycle time was approxi-
mately 5 minutes on, and 5 minutes off. Under these conditions,
a photomultipi%er amplifier output signal voltage held within
a total range of 0.25 volt. This value should be satisfactory.
This value was calculated from measurements made at high photo-
multiplier gain which gave higher sensitivity to temperature
variations."
The conditions of the apparatus were as follows:
A) The tank used was the existing plastic tank with
holes drilled in the sides for insertion of the pump inlet and
the heater.
B) Water flow rate - 4 ounces per minute.
S
C) Pump was a I centrifigual impeller 25X1A
pump. Little difference was observed with and without a
stirrer when the pump inlet was located close to the heater,
which it would be in the final design.
D) The fan was found not to be necessary under the
above conditions.
E) Tubing length - 12 feet each.
We have assured ourselves that the approach taken is
valid. We are presently modifying five (5) production Inter-
ferometers with the "fixes" and will retest these five pro-
duction units to assure ourselves. that the breadboard "fix"
proves valid when production designed, engineered and produced.
The production units are presently in the factory to be com-
pleted by September 16, 1966. The test program will begin on
September 19, 1966, and will run for approximately two (2)
weeks.
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We understand that will visit our plant
on September 21-22, 1966, and we have invited him to view the
tests on these production units. it is felt that upon com-
pletion of these production units, modification kit; can be
made for all your Interferometers, and the modifications made
in a relatively short period of time. We will keep you in-
formed of our activities, as .well as show the physical changes
to 17 during his visit.
We appreciate your patience in this regard, and wish to
again thank you for your assistance in bringing this matter
to our attention. The results should be beneficial to all
parties. If we can provide you with any additional information,
please do not hesitate to contact us.
Very truly yours
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