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
- Application Number:
- PPN: US 7-758045
- Assignee:
- Dept. of Energy, Washington, DC (United States)
- 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 = {Tue Oct 06 00:00:00 EDT 1992},
month = {Tue Oct 06 00:00:00 EDT 1992}
}