x 10°75 amp/r/hr and insulation of more than 1013 ohms, The integrating capacitors (0.3 and 1.3 microfarads) had a time constant of more than 3 days. These capacitors were in the electrometer circuit. The ionchamber current charged whichever capacitor was in use so as to reduce the grid potential of a CK588 electrometer tube and, hence, increase the positive plate voltage of a CK526AX amplifier tube. This increased plate voltage resulted in an increased cathode current in this tube, This increased cathode current raised the cathode potential and caused a current to flow in the microameter loop. It also resulted in negative feedback in the input to the CK58&6, since it tended to cancel out the voltage produced by charging the integrating capacitors, The negative feedback had the beneficial action of effectively miltiplying the capacity of the capicators without increasing the leakage; hence, the dynamic range of the instrument was extended without excéeding the straight-line portion of the versus I. characteristic curve of the CK5886, The three instruments just discussed (P-Meter, Bioscel, and Sigmatron) all have a response time of less than 1 second for 100 percent Tesponse. lonization Chamber TS de a | Figure 2.3 2.2.4 Meter Circuit Feedback Circuit | Block diagram of Signatron radiation-integrating dosimter, Other Dosimeters., The integrated gamma radiation dose during cloud passage and on the return flight was measured by a number of stand- ard integrating dosimeters. Each crew member carried pencil-type dosineters and a Rad-Safe film badge. Quarts-fiber dosimeters were mounted in the cockpit to record the total dose received on the mission. The NBS packs were placed in both the pilot's and observer's compartments. The NES film packs were also mounted in the nose compartment for comparison of the total dose received in the nose with that received in the cockpit, This latter comparison was necessary, because the P-Meter was mounted in the .ose compartment while the sensing elements of all other instruments were in the cockpit. a, The AN/PDR=39 (T1B) is a standard Air Force gamma rate meter and was used to follow the decay rate in the pilot's and observer's positions after completion of the flight. This study continued for 12 hours. Information concerning this instrument can be obtained through Air Force Supply channels, oo ee 2.2.5 Intervalometer. The intervalometer, as its name implies, was a device used to actuate the camera in the photopanel at selectable intervals, at KAFB, It was designed and built by the 4925th Test Group (Atomic) One of these instruments, along with the associated photopane) 17 BEST AVAILASLE COPY