FINE INSTRUMENTS CORPORATION FINEST 135, User Manual

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5.9 Measuring Resistance 5.10 Continuity Testing
Press the pushbutton enable the resistance
ment mode. This Meter defaults in the autoranging mode and
displays KR and AUTO. And also the
arrow of the
bar graph blinks and the digital display reads OFL.
AUTO (autoranging) applied to the bar graph.
This Meter measures resistance by comparing the internal
reference resistance given by a resistor array with the
unknown resistance
be measured. Remember, the
sistance displayed by this Meter the total resistance
through all possible paths between the probes. This explains
why in-circuit measurement of resistors does not
yield
the ohms value indicated by the resistor’s
CAUTION!
TURN OFF POWER ON THE TEST AND
CHARGE ALL CAPACITORS BEFORE ATTEMPTING
CIRCUIT RESISTANCE MEASUREMENTS.
AN
TERNAL VOLTAGE PRESENT ACROSS A
PONENT, IT WILL BE IMPOSSIBLE TO TAKE AN
CURATE MEASUREMENT OF THE RESISTANCE OF
THAT COMPONENT.
The resistance in the leads diminish accuracy on
i
the lowest range. The error 0.1 to 0.2
ohms for a Standard pair of test
Press the
l
$j pushbutton enable the continuity testing
mode. This Meter in the range and then
highest bar graph 400. The digital display reads
OFL.
Continuity testing verifies circuit connections are
Test resistances below the Meter emit a
tinuous tone.
Table 1. Beeper in Continuity Test
Input Range Beeper On
Approx.
The continuity mode is extremely fast and be
detect either or opens that last for as as 100
liseconds. When a detected, the beeper tone is
“stretched” last at least so you hear it
and detect both and opens.
This be a valuable troubleshooting aid when looking for
intermittents associated with cables connections, switches,
relays, etc. the
value is very to the threshold,
beeps also occur due environmental electrical
noise (EMI).
When measuring resistance, be sure the contact
tween the probes and the circuit good. Oil,
or other foreign matter seriously resistance.
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