LESSON 2
THE DC POTENTIOMETER SYSTEM
TASK
Describe the operation of the dc potentiometer system.
CONDITIONS
Given information and illustrations about the use and operation of the dc
potentiometer system.
STANDARDS
Demonstrate competency of the task skills and knowledge by correctly
responding to 80 percent of the multiple-choice test covering the dc
potentiometer system.
REFERENCES
Guildline Instruments technical manuals.
INTRODUCTION
In the Army Calibration Laboratory, the dc potentiometer system is the most
accurate voltage measuring device. The system is comprised of a Model 9931
DC Comparator Potentiometer, a Model 9771 Constant Current Source (CCS), a
Model 9460A Nanovolt Amplifier, a Model 9461B Galvanometer, and a Model
9154B Standard Cell Enclosure.
Learning Event 1:
DESCRIBE THE MODEL 9931 DC COMPARATOR POTENTIOMETER
1.
Functional description.
The Guildline Instruments Direct Current
Comparator Potentiometer, Model 9931, is a seven-dial potentiometer which is
used in conjunction with a CCS, a nanovolt amplifier, a standard cell
enclosure, and a galvonometer to make precision voltage measurements (fig
2-1).
a. The instrument is designed to measure voltage in two ranges; 0 to 2
volts at an accuracy of (0.5 ppm of reading + 0.05 V), and 0 to 0.2 volts
at an accuracy of (1 ppm of reading + 0.02 V).
The resolution of the
instrument in these two ranges is 0.1 V and 0.01 V respectively.
In
addition to its use in precision voltage measurement, the potentiometer can
be used for standard cell comparisons.
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