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Title: Low noise charge ramp electrometer

Abstract

An electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit. 2 figs.

Inventors:
;
Issue Date:
OSTI Identifier:
7240010
Patent Number(s):
5153502 A
Application Number:
PPN: US 7-758045
Assignee:
Dept. of Energy, Washington, DC (United States) PTO; EDB-94-090539
DOE Contract Number:  
AC07-84ID12435
Resource Type:
Patent
Resource Relation:
Patent File Date: 12 Sep 1991
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; ELECTROMETERS; BACKGROUND NOISE; DESIGN; ELECTRIC CURRENTS; SIGNAL-TO-NOISE RATIO; CURRENTS; ELECTRIC MEASURING INSTRUMENTS; ELECTRICAL EQUIPMENT; EQUIPMENT; MEASURING INSTRUMENTS; NOISE; 440800* - Miscellaneous Instrumentation- (1990-)

Citation Formats

Morgan, J.P., and Piper, T.C. Low noise charge ramp electrometer. United States: N. p., 1992. Web.
Morgan, J.P., & Piper, T.C. Low noise charge ramp electrometer. United States.
Morgan, J.P., and Piper, T.C. Tue . "Low noise charge ramp electrometer". United States.
@article{osti_7240010,
title = {Low noise charge ramp electrometer},
author = {Morgan, J.P. and Piper, T.C.},
abstractNote = {An electrometer capable of measuring small currents without the use of a feedback resistor which tends to contribute a large noise factor to the measured data. The electrometer eliminates the feedback resistor through the use of a feedback capacitor located across the electrometer amplifier. The signal from the electrometer amplifier is transferred to a electrometer buffer amplifier which serves to transfer the signal to several receptors. If the electrometer amplifier is approaching saturation, the buffer amplifier signals a reset discriminator which energizes a coil whose magnetic field closes a magnetic relay switch which in turn resets or zeros the feedback capacitor. In turn, a reset complete discriminator restarts the measurement process when the electrometer amplifier approaches its initial condition. The buffer amplifier also transmits the voltage signal from the electrometer amplifier to a voltage-to-frequency converter. The signals from the voltage-to-frequency converter are counted over a fixed period of time and the information is relayed to a data processor. The timing and sequencing of the small current measuring system is under the control of a sequence control logic unit. 2 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1992},
month = {10}
}