RSI Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

Aug 2000

Volume 71, Issue 8, pp. 2959-3233

Return to All Sections
back to top
RSS Feeds

Femtoampere current reference stable over atmospheric temperatures

R. Giles Harrison and Karen L. Aplin

Rev. Sci. Instrum. 71, 3231 (2000); http://dx.doi.org/10.1063/1.1304859 (2 pages) | Cited 8 times

Full Text: | Download PDF

Show Abstract
Calibration of ultralow current ammeters deployed in atmospheric ion counters requires stable current references operating at high source impedance. Using standard precision components, this current reference generates equal bipolar currents of nominally ±500 fA, cyclically for 32 s each. The currents were found to be stable to 2 fA over the temperature range −20 to 20 °C, typical of atmospheric conditions. The output current is delivered via a capacitor, and by arranging for the capacitor to be guarded at ground potential when the system is not generating a current, the reference can be permanently connected to an electrometer with minimal leakage. © 2000 American Institute of Physics.
Show PACS
93.85.-q Instruments and techniques for geophysical research: Exploration geophysics
07.68.+m Photography, photographic instruments; xerography
06.20.F- Units and standards
84.37.+q Measurements in electric variables (including voltage, current, resistance, capacitance, inductance, impedance, and admittance, etc.)

Current mode Schmitt trigger for a phototransistor/resistor detector

Tai-Shan Liao and Chun-Ming Chang

Rev. Sci. Instrum. 71, 3233 (2000); http://dx.doi.org/10.1063/1.1304860 (1 page)

Full Text: | Download PDF

Show Abstract
A current mode Schmitt trigger for a phototransistor/resistor detector is presented. It can be successfully operated with a 1.5 V power supply. © 2000 American Institute of Physics.
Show PACS
84.30.Sk Pulse and digital circuits
85.60.Gz Photodetectors (including infrared and CCD detectors)
84.30.Le Amplifiers
85.60.Dw Photodiodes; phototransistors; photoresistors
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close