at the corresponding scales and radiation fields shown in the chart below. Switch Position Seale Apply Adjust Radiation Intensity Resistor A 0.005 mr/hr R=35 B O.1 mr/hr R~36 Cc 10 mr/nr R-33 D 1000 mr/hr R-3), Altitude Compensation Circuit The proper compensation voltage for attenuation factors corresponding to a particular contaminated area can be determined and set while in flight by the following procedure. A. Be C. 2, Make passes over the same section of a contaminated area at 200' and 1000', Subtract the current reading on the aircraft radiation recorder obtained at 1000' from the one obtained at 500°. Then using the curve shown in Figure 11, determine the voltage corresponding to the difference in current between the 500 and 1000 foot readings, adjust R-38 to obtain this voltage across the compensation potentiometer. Operation To assure minimum radiation absorption by the aircraft, the "Top Hat" detector is positioned so that only the skin of the aircraft separates it from the outside. in the tail section. The most suitable location is usually Also, the tail position is furthest removed from radioactive dial instruments in the pilot's compartment. fhe control box is located with the operator. To set the unit in operation: A. Set the altitude compensation toggle switch (S-2) to either "automatic™ or "manual" depending on the type of operation desired. When using manual altitude compensation, the - 2h =