Smart Digital Multimeter UNI-T UT123D

UNI-T UT123D Digital Multimeter, True RMS, 600 V, 10 A, NCV

The UNI-T UT123D is a compact digital multimeter intended for household electrical work, DIY projects and basic electrical or electronic measurements. It can automatically recognize several common input signal types and select the corresponding function and range, reducing the number of manual settings required. The UT123D measures AC/DC voltage and current, resistance and capacitance and also provides True RMS, NCV, LIVE, diode and continuity functions.

Key specifications: True RMS • up to 600 V AC/DC • up to 10 A AC/DC • up to 40 MΩ • up to 4000 µF • NCV / LIVE • CAT III 600 V

Key advantages

• Automatic measurement recognition – the meter can automatically identify AC/DC voltage, resistance, diode and continuity measurements and select the appropriate range.
• True RMS measurement – AC voltage and current are measured using True RMS, providing more meaningful RMS readings for non-ideal AC waveforms than conventional average-responding meters.
• Up to 600 V and 10 A – covers many common voltage and current measurements encountered in household electrical systems, electronics and general troubleshooting.
• Resistance up to 40 MΩ and capacitance up to 4000 µF – suitable for checking resistors, circuits and a wide range of capacitors.
• NCV non-contact voltage detection – provides an indication of the presence and relative strength of an AC electric field without direct probe contact.
• LIVE function – allows identification of a live conductor using a single test probe, with audible and visual indication when the required AC voltage is detected.
• Automatic current-mode switching – inserting a test lead into the current input can automatically switch the meter to current measurement.
• EBTN display and compact housing – a 4099-count display combined with a 130 × 65 × 28 mm body makes the meter easy to carry and read.
• Data Hold and Auto Power Off – the displayed reading can be held, while the meter powers down automatically after approximately 15 minutes of inactivity.
• CAT III 600 V rating – specified for measurements within the manufacturer's stated CAT III 600 V operating limits.

Applications

UNI-T positions the UT123D primarily for home users, beginners and DIY work. It can be used for checking household electrical circuits, measuring voltage and current, testing electronic components, checking wire continuity, measuring resistance and capacitance and carrying out preliminary live-conductor identification.

It is also useful for basic maintenance and troubleshooting, but the manufacturer does not position the UT123D as a high-accuracy laboratory or specialized industrial multimeter.

Compatibility and limitations

• Requires 2 × 1.5 V AAA / R03 cells for operation.
• Separate COM, VΩ and current measurement inputs are provided.
• True RMS AC voltage and AC current frequency response: 40–400 Hz.
• Manufacturer documentation does not specify Bluetooth, USB or a computer data interface. “Smart” in the UT123D designation refers to automatic function/range recognition rather than wireless connectivity.
• Temperature and frequency measurement are not listed as supported UT123D measurement functions.
• NCV is an indicative non-contact detection function. Sensitivity can be affected by distance, wire insulation thickness and outlet or conductor construction, so NCV should not be treated as a substitute for a direct contact voltage measurement.
• Automatic recognition thresholds are not the lower limits of the measurement ranges. The manual specifies approximate recognition thresholds of about 0.5 V DC, 0.4 V AC, 1 mA DC and 2 mA AC.

Technical specifications

Parameter	Specification
Maximum display	4099 counts
Display	EBTN LCD
Display size	44 × 26 mm
Reading update rate	approx. 3 readings/s
Range selection	automatic; measurement modes can also be selected manually
True RMS	AC voltage and AC current
DC voltage ranges	4.000 V / 40.00 V / 400.0 V / 600 V
DC voltage resolution	0.001 V / 0.01 V / 0.1 V / 1 V
DC voltage accuracy	±(0.5% of reading + 3 digits)
AC voltage ranges	4.000 V / 40.00 V / 400.0 V / 600 V
AC voltage resolution	0.001 V / 0.01 V / 0.1 V / 1 V
AC voltage accuracy, 4.000 V	±(1.0% + 5)
AC voltage accuracy, 40.00–600 V	±(0.8% + 3)
AC voltage frequency response	40–400 Hz
Voltage input impedance	>10 MΩ
DC current ranges	999.9 mA / 9.999 A
DC current resolution	0.1 mA / 0.001 A
DC current accuracy	±(1.0% + 3)
AC current ranges	999.9 mA / 9.999 A
AC current resolution	0.1 mA / 0.001 A
AC current accuracy	±(1.2% + 3)
AC current frequency response	40–400 Hz
Resistance ranges	400.0 Ω / 4.000 kΩ / 40.00 kΩ / 400.0 kΩ / 4.000 MΩ / 40.00 MΩ
Resistance resolution	0.1 Ω / 0.001 kΩ / 0.01 kΩ / 0.1 kΩ / 0.001 MΩ / 0.01 MΩ
Resistance accuracy, 400.0 Ω	±(1.0% + 2)
Resistance accuracy, 4.000–400.0 kΩ	±(0.8% + 2)
Resistance accuracy, 4.000 MΩ	±(1.5% + 3)
Resistance accuracy, 40.00 MΩ	±(2.0% + 5)
Capacitance ranges	40.00 nF / 400.0 nF / 4.000 µF / 40.00 µF / 400.0 µF / 4000 µF
Capacitance resolution	0.01 nF / 0.1 nF / 0.001 µF / 0.01 µF / 0.1 µF / 1 µF
Capacitance accuracy, 40.00 nF	±(4% + 10)
Capacitance accuracy, 400.0 nF–400.0 µF	±(4% + 5)
Capacitance accuracy, 4000 µF	±10%
Diode test	yes; 4.000 V range, 0.001 V resolution
Continuity test	buzzer at ≤30 Ω; no buzzer at ≥50 Ω
NCV	non-contact AC electric-field detection with audible and visual indication
LIVE	single-probe live-wire identification; manual specifies triggering at ≥70 V AC, 50/60 Hz
Data Hold	yes
Low battery indication	yes
Auto Power Off	approx. 15 min; can be disabled
Additional non-sinusoidal AC error	crest factor 1–2: +3%; 2–2.5: +5%; 2.5–3: +7%
Current-input fuse	10 A / 600 V fast-acting ceramic fuse, Ø6 × 25 mm
Safety category	CAT III 600 V
Certification marks	CE, UKCA
Operating temperature	0–40 °C
Drop resistance	1 m
Power supply	2 × 1.5 V AAA / R03
Dimensions	130 × 65 × 28 mm
Net weight	130 g
Reference conditions for stated accuracy	23 ± 5 °C, ≤80% RH; one-year calibration period

Accuracy note: a specification such as ±(0.5% + 3) means ±(percentage of the reading + digits). Resolution must not be interpreted as the minimum reliably measurable value.

Design and controls

The UT123D does not use a conventional multi-position rotary range selector. Its main measurement functions can be recognized automatically, while the required mode can also be selected using the control buttons. A dedicated HOLD function freezes the reading, while NCV/LIVE controls are used for non-contact field detection and live-conductor identification.

The EBTN display and compact 130 × 65 × 28 mm housing are designed for portable use. UNI-T also specifies resistance to a 1 m drop.

Important operating and safety information

• Do not exceed 600 V between the measurement terminals or between a terminal and earth, and observe the CAT III 600 V limits.
• Disconnect power from the circuit and discharge capacitors before measuring resistance or capacitance or performing diode and continuity tests.
• Current must be measured with the meter connected in series with the circuit. Switch off circuit power before changing current-measurement connections whenever practicable.
• Inspect the meter housing and test-lead insulation before use. Do not use damaged equipment.
• NCV and LIVE are indication aids. Before working on electrical conductors, verify the absence of hazardous voltage using an appropriate contact measurement method.
• When replacing the current-input fuse, use the same specified 10 A / 600 V fast-acting ceramic Ø6 × 25 mm fuse.

Package contents

• Test leads / probes – 1 pair.