7792

• UCREFRP Catalog Number: 7792
• Author: Kolz, A. L.
• Title: In-water Electrical Measurements for Evaluating Electrofishing Systems.
• USFW Year: 1993.
• USFW - Doc Type: \
• Copyright Material: NO

16 BIoLoGICAL REnoRT 11
50
45
40
35
E 30
IL 25
0
20
15
10
5
0
0
50
45
40
35
o -four rods with 0.64-cm diameter
x - six sods with 0.64-cm diameter
I - four rods with 2.54-cm diameter
+ - six sods with 2.54-cm diameter
60-cm-length rods suspended from 30.5-cm ring
50 100 150 200
Distance (centimeters)
30
25
0
20
15
10
5
0
0
50 100
Distance (centimeters)
150
sions, the voltage gradient profiles have a wavy
appearance caused by measurement artifacts. The
numerical calculations for voltage gradient proved
to be extremely sensitive to incremental variations
in the slope of the voltage profiles, and I found that
a measurement error as small as 0.1 volt could
create a noticeable undulation in a voltage gradi-
ent curve. I will leave it to the reader to mentally
average a smooth curve through these experimen-
tally induced oscillations.
o - four sods with 0.64-cm diameter
w - four rods with 2.54-cm diameter
• - six rods with 2.54-cm diameter
60-cm-length rods suspended from 58-cm ring
200
Fig. 15. Voltage profiles for Wisconsin
arrays with four and six rods sus-
pended from a 30.5-cm supporting
ring.
Fig. 16. Voltage profiles for Wisconsin
arrays with four and six rods sus-
pended from a 58-cm supporting ring.
The initial values of voltage gradient plotted on
Figs. 18 through 23 are not to be interpreted as the
maximum values of voltage gradient generated in
proximity to an electrode. It would require a re-
fined measuring technique to extrapolate this
maximum from a voltage profile, and this level of
sophistication was beyond the intent of the study.
Furthermore, it should be a standard practice
when electrofishing to protect the fish from enter-
ing this region of the electric field. The most haz-