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    Apollo Command Module Environmental Control System Hardware: Two Glycol Temperature Sensors, AiResearch Part 820920 (Contract NAS-9-150). These odd-shaped metal components, 6.625" x 2.5" x 2" (overall), each have a multi-pin electrical connector at top and two screw-on pressure connectors on opposite ends with red "Warning/ Dielectric/ Testing/ Completed" stickers. The metal ID plates along the rounded top portion presents the following data: "Sensor Glycol Temp./ Part 820920-2-1/ Serials 86-R1 / 86-R2". One is stamped in ink as "Not Acceptable For Flight" with two inspector stamps; the other has neither. Included are several pages copied from a 1973 abstract prepared by AiResearch for the NASA MSC titled "Environmental Control System Transducer Development Study". It reads, in part: "The initial design of glycol temperature sensor PN 820920-2 was implemented on the Apollo Block I and Block II ECS. Because of numerous failures this design was superseded by a new design, PN 836172, which was implemented on Apollo Block II ECS. The current glycol temperature sensor is a combination of thermistor bead and coil type sensor. Subject glycol temperature sensor senses the temperature of the water-glycol coolant at the outlet of the glycol evaporator. The unit consists of a metal housing containing two glass-sealed thermistors, a coil type sensing element, a resistance bridge circuit, and a transformer coupled output circuit." Both very fine.

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    Auction Dates
    November, 2014
    12th Wednesday
    Bids + Registered Phone Bidders: 1
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