scholarly journals Oscilloscope trace photograph digitizing system (TRACE). [FAWTEK code]

1977 ◽  
Author(s):  
M. Richards ◽  
R.D. Dabbs
Keyword(s):  
1969 ◽  
Vol 47 (4) ◽  
pp. 398-400 ◽  
Author(s):  
Peter Graystone ◽  
Neville Owen ◽  
Hugh McLennan

A simple circuit has been described which gives a meter reading proportional to the rate of cell firing. The circuit will trigger reliably on any signal exceeding 100 mV, and a trigger-level control is provided to enable triggering to be suppressed below a threshold level. An external recorder may be driven from the circuit. In addition the circuit provides a pulse which may be used to modulate the intensity of an oscilloscope trace each time the threshold is exceeded.


1965 ◽  
Vol 20 (4) ◽  
pp. 599-606
Author(s):  
H. H. Brömer ◽  
F. Döbler

A microwave bridge, similar to the optical JAMIN interferometer, has been developed in order to determine the electron density in weakly ionized decaying plasmas. The discharge vessel was located in the open space between two horn antennas.A rather homogeneous excitation was accomplished by using an electrodeless high frequency (f = 13,6 MHz) discharge.Contrary to the common practice of using phase displacements several times of π, only very small displacements of the signal phase, traversing the plasma, have been used. The dimensions of the discharge vessel and the frequency of the microwave (f = 23 GHz; λ = 1,3 cm) have been properly chosen in order to have proportionality between the mean electron density and the oscilloscope trace. The range of electron-density investigated was about 108 to 1010 cm-3.The operation of the bridge has been investigated during the afterglow of a decaying nitrogen plasma.Simultaneous optical observations have shown that the intensity of the first negative bands of N2+ (B2Σu+-Χ2Σg+) is nearly proportional to the electron density. Using this correlation, the electron density profile across the discharge vessel has been evaluated. It could be shown that the time dependance of the electron density in the afterglow changes strongly within the discharge vessel. A comparison between the measurements of the electron density and the optical observations has shown that the microwave bridge is able to give some details of the electron density profile across the discharge vessel, inspite of the large wavelength used, compared with the dimensions of the discharge vessel.


1972 ◽  
Vol 94 (2) ◽  
pp. 429-433
Author(s):  
J. R. Glover ◽  
F. A. Locher ◽  
P. K. Bhattacharya

A computer-based system utilizing an electro-optical instrument has been developed for generating and processing a signal proportional to the instantaneous sand concentration at a point in a flow field. Herein are described the instrumentation and techniques used in a study of sediment entrainment by periodic waves breaking on sand beaches. The instantaneous sediment concentration has been decomposed as follows: C(x,y,z,t)=C¯(x,y,z)+C′(x,y,z,t)+Cp(x,y,z,t) where C(x, y, z) is the temporal average concentration, C′(x, y, z, t) is a random component of the sediment concentration, and Cp(x, y, z, t) is a repetitive component with period equal to the period of the breaking waves. Particular attention has been given to isolating the repetitive component which was so obscured by the signal characteristics that no periodicity was apparent on either an oscilloscope trace or a strip chart recorder. Spectral analysis was not applicable because the shape of the repetitive waveform, Cp(x, y, z, t), over one wave cycle was desired.


1981 ◽  
Vol 27 (97) ◽  
pp. 459-469 ◽  
Author(s):  
Raymond D. Watts ◽  
David L. Wright

Abstract Equipment has been designed and tested for ground-based and airborne sounding of temperate glaciers. The transmitter is a free-running pulse generator that uses avalanche-mode transistor breakdown to create high-voltage pulses. The transmit and receive antennas are resistively loaded dipoles; for the airborne system, a twin-lead transmit element and a three-layer coaxial receive element are used on the inboard end of the respective antennas. The sounders are broadband systems; oscilloscopes are used for receivers. The oscilloscope trace is recorded photographically in the ground-based systems. A sampling oscilloscope is used in the airborne system—the sampling process strobes the waveform to audio frequencies so that it can be recorded on magnetic tape. Echoes have been obtained from ice depths of 550 m using the airborne system and about 1 000 m using the ground-based system.


1990 ◽  
Vol 259 (6) ◽  
pp. S15 ◽  
Author(s):  
P H Barry

MEMPOT is an interactive graphic simulation program, written in Turbo C for IBM-PC-compatible equipment and designed to teach students in the physiological and biological sciences about the measurement and ion dependence of cell membrane potentials. Different external salt solution values can be chosen and an intracellular electrode can be moved on the screen to impale one of a group of cells and measure resting or action potential responses. A simulated voltage-to-frequency audio signal emulates normal experimental audio monitoring of the electrode potential, and a window displays a simulated oscilloscope trace (together with "electrical noise") of the resting or action potential response. The average value of each set of successful impalements is determined for each solution. Once measurements have been made over a suitable range of different solutions, the data can be reentered and plotted graphically on the screen and an interactive approach can be used to determine relative sodium-to-potassium permeabilities at rest or at the action-potential peak. A randomization routine varies permeability ratios within a small range between runs.


1981 ◽  
Vol 27 (97) ◽  
pp. 459-469 ◽  
Author(s):  
Raymond D. Watts ◽  
David L. Wright

AbstractEquipment has been designed and tested for ground-based and airborne sounding of temperate glaciers. The transmitter is a free-running pulse generator that uses avalanche-mode transistor breakdown to create high-voltage pulses. The transmit and receive antennas are resistively loaded dipoles; for the airborne system, a twin-lead transmit element and a three-layer coaxial receive element are used on the inboard end of the respective antennas. The sounders are broadband systems; oscilloscopes are used for receivers. The oscilloscope trace is recorded photographically in the ground-based systems. A sampling oscilloscope is used in the airborne system—the sampling process strobes the waveform to audio frequencies so that it can be recorded on magnetic tape. Echoes have been obtained from ice depths of 550 m using the airborne system and about 1 000 m using the ground-based system.


1968 ◽  
Vol 39 (10) ◽  
pp. 1429-1433 ◽  
Author(s):  
F. C. Jobes
Keyword(s):  

1957 ◽  
Vol 190 (2) ◽  
pp. 194-200 ◽  
Author(s):  
Frederick Ware ◽  
A. L. Bennett ◽  
A. R. McIntyre

Intracellular potentials from isolated normal frog hearts were measured in a series of 29 experiments, using microelectrodes of less than 1 micron tip diameter, a cathode follower input, direct coupled amplifier, and photographic registration of an oscilloscope trace. The perfusion fluid was Clark's solution, containing 1.08 mm calcium and 1.88 mm potassium. The average of 485 measurements of the normal resting potential was 84.5 mv. The average of 421 measurements of overshoot was 18.9 mv; and the average of 421 measurements of action potential was 102.5 mv. In eight experiments, including 141 values, the maximum depolarization rate was determined, using a graphical method of analysis. The average maximum upstroke velocity was 33.9 v/sec. The voltage-time curve of the action potential during the repolarization sequence showed considerable variation from fiber to fiber, but in most cases some evidence of a ‘spike’ component was seen.


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