KYORITSU 4105A User Manual
Page 6
4. Layout Diagram
q
LCD Display
w
Battery Replacement Mark
e
Indication LED With
(Low Battery Symbol)
Measurement(Green)
r
Press To Test Button
t
Range Selector Switch
y
Measuring Terminals
u
Test Leads
i
Auxiliary Earth Spikes
o
Simplified Measurement Probe
!0
Safety Alligator Clip
!1
Test Bar
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5. Preparation for Measurement
5-1 Battery Voltage Check
Turn on the instrument. If the display is clear without low battery symbol
"
" showing, battery voltage is sufficient. If the display blanks or "
" is
indicated, replace the batteries according to section 7 for Battery
Replacement.
5-2 Connecting Test Probe
Insert the plug of the probe securely into the terminals of the instrument.
Loose connection may result in inaccurate measurements.
6.Operating Instructions
DANGER
The instrument will produce a maximum voltage of about 50V between
terminals E-C in earth resistance function. Take enough caution to
avoid electric shock hazard.
When measuring earth voltage, do not apply voltage greater than 200V
between measuring terminals.
When measuring earth resistance, do not apply voltage between
measuring terminals.
6-1 Principle of Measurement
This instrument makes earth resistance measurement with fall-of-
potential method, which is a method to obtain earth resistance value Rx
by applying AC constant current
I between the measurement
object E (earth electrode) and C
(current electrode), and finding
out the potential difference V
between E and P (potential
electrode).
Rx = V / I
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