Hioki DT4200 Series - Page 3

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The DT4255’s voltage input terminals incorporate a
protective fuse so that contamination of the instrument’s
internal components with iron powder or other particulate
matter will not result in an internal short-circuit. The fuse
can be replaced easily on site.
The DT4281, DT4282 and DT4261 use terminal shutters to
keep probes from being inserted into the wrong inlets. The
shutters block whichever terminal is not being used based
on the selected measurement function.
To prevent an accident, a warning function immediately
noties the operator if the DMM receives excessively high
input.
The DT4281, DT4261, DT4253, DT4255 and DT4256
eliminate the root cause of such accidents by providing
clamp-on sensor-based current measurement functionality
instead of using conventional probes.
*Red screen available on high-end models and DT4261, DT4223, DT4224 only.
A range: Only the A and COM terminal inlets open.
V range: Only the V and COM terminal inlets open.
Prevent unavoidable debris from shorting the
measurement target and causing an accident.
Mistakenly tripped circuit breakers and arcs due to careless input of voltage to the resistance range
can be extremely hazardous.
Wrong insertion
may lead to short-circuits.
Continued high input may result in major
accidents such as re.
Mistakenly measuring voltage using the
current range may lead to a short-circuit.
Hazard
1
Erroneous circuit-breaker activation Arcing and sparks
Switch to resistance range Switch to resistance range Switch measurement circuit Switch measurement circuit
Because changing the measurement range also changes the
measurement circuit, mistakenly inputting voltage with the instrument
set to the resistance range will cause a large current to ow to the
device, leading to hazards such as tripped circuit breakers and arcing.
The measurement circuit is switched after the instrument detects
resistance, continuity, capacitance, or diode input. Even if you
mistakenly input voltage with the instrument set to the resistance range,
the high input impedance will limit the current owing to the instrument
to 1.5 mA or less to prevent potential hazards.
Detect input
Resistance range
measurement circuit
Input-based switching of the
measurement circuit
Voltage range
measurement circuit
Resistance range
measurement circuit
The DT4223 and DT4224 feature a new proprietary function that prevents
accidents resulting from breakers that mistakenly trip due to incorrect input
Conventional digital multimeters DT4223 / DT4224 Digital Multimeter
High input impedance
1.5 MΩ
or greater
High input impedance
1.5 MΩ
or greater
Low input impedance
Constant current generation
circuit for measurement
Low input impedance
Constant current generation
circuit for measurement
Safe testers that protect workers
from dangerous accidents
Hazard
2
Hazard
4
Hazard
3
Hazard
5