Accession Number : ADD004604

Title :   Automatic Span Circuit.

Descriptive Note : Patent,


Personal Author(s) : Tucker,Huel C

Report Date : 07 Jun 1977

Pagination or Media Count : 5

Abstract : An analyzer, for measuring the concentration of a particular material in a sample, has its analog voltage output connected to the analog input of a multiplying digital-to-analog converter (MDAC) whose output is connected to a voltmeter and to one input of a voltage comparator having its other input connected to a potentiometer and battery producing a reference voltage somewhat less than the known output voltage of the sample. The comparator output is connected to two gates which control the transmission of electrical pulses from a generator to the UP or DOWN inputs of a binary UP/DOWN counter, in such manner that the counter counts UP, increasing the gain of the MDAC, when the MDAC output voltage is lower than the reference voltage, or counts DOWN, decreasing the MDAC gain, when the MDAC output voltage is higher than the reference voltage.

Descriptors :   *Patents, *Chemical analysis, *Analyzers, *Calibration, Concentration(Chemistry), Comparators, Digital to analog converters

Subject Categories : Industrial Chemistry and Chemical Processing
      Electrical and Electronic Equipment

Distribution Statement : APPROVED FOR PUBLIC RELEASE