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DLRO10 and DLRO10X
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2. GENERAL DESCRIPTION
The DUCTER DLRO10 and DUCTER DLRO10X make up a family of low resistance
ohmmeters that measure resistances in the range from 0.1 μΩ to 2 kΩ. Both
instruments provide a maximum test current of 10 Amps d.c. which is automatically
selected according to the value of resistance being tested. The DLRO10X allows you to
override this automatic selection and select your own test current.
The measured value of resistance is output to the instrument display with indication of
the units, μΩ, mΩ or Ω. The DLRO10 uses a large LED display and indicators to display
the value and units respectively, while the DLRO10X contains all the information on a
clear colour display.
The use of a four terminal measurement technique removes the test lead resistance
from the measured value and auto current reversal eliminates the effect of standing
voltages across the test sample. Additionally, before and during a test, test lead
contact is monitored to further reduce the chance of erroneous readings.
A resistance measurement takes approximately 2.5 seconds and comprises a
measurement with forward current, reverse current and a display of the average. On
the DLRO10X all three values are displayed, and optionally, the measurement may be
limited to forward current only.
The instrument is powered by a rechargeable Lithium ion (Li-ion) battery, which
permits thirteen hundred 10 Amp tests to be completed on a single charge. The
battery module contains intelligent circuitry, which prevents damage to the battery
from overcharging, and a battery state indicator. A removable lid that is hinged at
the back and held closed by magnetic catches covers the top panel. This lid may be
removed if required by opening fully and snapping out of its hinges.
Both instruments are protected against accidental connection to external voltages up
to 600 V d.c. applied between any pair of the four terminals for up to 10 seconds.
Please note that applying 600 V to the potential terminals will cause some
internal heating. Expect errors of up to 30 digits immediately after the
application of such voltage. Full accuracy will be restored within two to three
minutes.
Both instruments are supplied complete with a pair of DH4 Duplex Handspikes with
1.2 m leads. Other lengths and terminations are available if required.
3. General Operation - DLRO10
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Item
Description
Item
Description
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Test current
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Excess noise
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Contact fail indicator
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Mode control
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Voltage terminals
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Brightness
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Current flowing
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On/Off
Press the On/Off switch to turn DLRO10 on. All lamps will light, V and I lamps will
flash, the software version will be displayed and the Ω lamp will light. If the test leads
have not been connected to the test sample the ‘C’ and ‘P’ lamps will also light. Press
the On/Off button again to turn the instrument off. If the instrument is not used for 5
minutes it will be turned off automatically.
3.1 Adjust the brightness control to a comfortable level.
Select the Test mode by pressing the Mode button repeatedly. The indicator lamps will
cycle through the various Test modes in turn (see the section on Test modes). Press the
Test button to start a test.
3.2 Test Current Indicators
The test current is selected automatically by DLRO10 and is indicated by the lamps on
the left of the panel. The measured value is displayed in the main window and the
units (µΩ, mΩ or Ω) are shown by the lamps to the right of the window.
