Accession Number : AD0011376


Title :   HIGH SENSITIVITY DC AMPLIFIER FOR BIOLOGICAL MEASUREMENTS


Descriptive Note : Technical rept. no. 8


Corporate Author : CORNELL UNIV MEDICAL COLL (WEILL) NEW YORK


Personal Author(s) : Thalhamer, Albert


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/011376.pdf


Report Date : 15 Feb 1953


Pagination or Media Count : 77


Abstract : The amplifier consists of push-pull stages from input to output circuits and provides for measurements in the range from 10 microvolts to 100 mv with 5 sensitivity positions. It is designed for use with auxiliary measuring or recording equipment having internal amplifiers. At the maximum sensitivity of 50 microvolts the peak-to-peak drift was 100 microvolts for a 30-min period. A short-term stability with 50 microvolts for 1 min is specified. The ability to discriminate against signals appearing inphase on both input grids is accomplished by the use of cathode-coupled 12J5's. The design specifications established are a sensitivity of 10 microvolts to give full-scale output with a maximum input of 100 mv, and input impedance of 10 megohms in the range 0 to 10 kc, a frequency response flat from 0 to 10 kc, an input grid current of 10 to the power of minus 10 amp, a drift less than 200 microvolts peak-to-peak over 30 min, a rise time of 10 microsecs, an in- to out-of-phase rejection ratio of 3000, and a completely line-operated power supply. A detailed circuit description and operating instructions are included.


Descriptors :   *BIOLOGY , *AMPLIFIERS , INPUT , OUTPUT , GRIDS , DRIFT , MEASURING INSTRUMENTS , CIRCUITS , PUSH PULL AMPLIFIERS , DISCRIMINATE ANALYSIS , FREQUENCY RESPONSE , RECORDING SYSTEMS , INTERNAL , SHORT RANGE(TIME) , STABILITY , AUXILIARY


Subject Categories : Biology
      Electrical and Electronic Equipment


Distribution Statement : APPROVED FOR PUBLIC RELEASE