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DLRO10 and DLRO10X
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At the end of the test both instruments will display the measured resistance, the
DLRO10 will flash the relevant current lamp while the DLRO10X will display the test
current used on the display.
Please note:- In inductive mode the 10 A test current will not be used.
5.5 Undirectional mode
On the DLRO10X only, this mode makes the measurement as in automatic mode but
using forward current only.
This mode speeds up measurements on samples that are known to be free of any
standing voltages or thermal emfs. However the accuracy of the reading may be
degraded by any thermal emfs but should not be worse than 0.2% ± 30 digits.
Since current is only applied in the forward direction, in this mode only a single
resistance value will be displayed.
A test may be repeated by breaking contact and reapplying the test probes or by
pressing the Test button.
6. TEST TECHNIQUES and APPLICATIONS
6.1 Testing Using Duplex Test Leads Fitted With Indicator Lamps
Each handspike is marked with the letter P. This indicates the potential terminals.
These should be the ‘inside’ contacts when making a measurement (as shown in the
next section ‘Testing Using Duplex Handspikes or Individual Leads’).
One of the DH4 handspikes is fitted with two lamps marked L1 and L2 and an extra
lead. This lead should be plugged into the 4 mm socket next to the main terminals
on the right hand side of the instrument. These lamps provide information to the
operator, which would otherwise only be available on the instrument display. The
meaning of these lamps is described below.
For example, using the DH4 or DH4-C Duplex Handspikes or any connecting test leads
with indicator lights with the DLRO10 in AUTO test mode:
1. Press the TEST button on the instrument.
2. Lamp L1 will illuminate a continuous red to indicate contact failure. See the
instrument panel for details if required.
3. When all four contacts connect, L1 will extinguish.
4. No lamps will show during the test unless contact fails.
5. Lamp L2 will light a continuous green when current flow has decayed to less
than 1 mA to signal end of test.
6. Removing the probes will extinguish the green L2 (end of test) and Light the red
L1 (no contact).
Since your DLRO always ensures good contact before applying the full test current,
there will be no ‘splash’ to erode the contact tips. However, should the tips become
worn or blunted, they can be simply replaced by pulling out the worn tips and
inserting new ones.
