The DET62D is a fully automatic, three terminal instrument
built into a rugged, water resistant case giving protection
for outdoor use. The instrument is suitable for the testing
of single ground electrodes such as lightning conductors
and other small grounding systems. The resistance of
conductors such as conduit coupling joints can also be
measured.
Ground resistance can be measured directly from 100 mΩ
to 2 kΩ. The ground resistance reading is displayed
quickly and accurately on a large, clear 3 1/2 digit liquid
crystal display. LEDs indicate when there is a high
auxiliary current spike or voltage probe resistance which
may affect the ground resistance measurement.
The instrument uses the three-terminal method of
measurement in which the ‘X terminal is connected to the
electrode under test and the ‘C’ and ‘P’ terminals are
connected to temporary, remote current and potential
electrodes. Operation is started by pushing a button on the
front panel. All other functions of the DET62D are
completely automatic. The instrument checks for
conditions that may cause an invalid reading during a test.
The low service error and wide operating temperature
range enable accurate results to be achieved in real on-site
conditions.
The test frequency has been chosen to avoid interference
from stray currents at power frequencies and their
harmonics. An LED indicates when the noise interference
is too high to take a valid reading.
Six 1.5 V AA dry cells provide power for the DET62D
allowing 700 typical 15 second tests. A low battery symbol
on the display gives an indication of battery condition.
The instrument is built into a small, lightweight case that
has been designed for outdoor use and has IP54
protection. Three large terminals allow either spade or
hook connectors, 4 mm plugs or bare ended wire to be
used for the test leads. A terminal shorting bar is provided
for continuity testing or ground electrode measurement
using the ‘dead ground’ method. A removable cover allows
access to the battery compartment. |