Hioki DT4221 Pocket True RMS Digital Multimeter

Key Features At A Glance

• True RMS measurement across the series for accurate readings of distorted current waveforms
• Drop-proof design built to withstand a 1 m drop onto concrete
• Designed and manufactured in Japan and backed by a 3-year warranty
• CAT III 1000 V/CAT IV 600 V on standard and high-end models; CAT III 600 V/CAT IV 300 V on pocket models
• DT4223 and DT4224 add circuit breaker false trip prevention to block arcs from mistaken resistance-range voltage input
• Low-pass filter isolates the fundamental wave for accurate inverter secondary-side voltage measurement
• USB data transfer to a PC via the optional DT4900-01 Communication Package with optical isolation
• Backlit wide-viewing-angle display, glove-friendly rotary switch, and O-ring dustproofing for field use

The Hioki DT4200 series is a line of digital multimeters engineered from extensive customer feedback to deliver the design and quality needed for safe measurement in the field. The series is organized into three groups: high-end models (DT4281 and DT4282) featuring high accuracy, extensive additional functionality, and a broad range of measurement parameters; standard models (DT4252, DT4253, DT4254, DT4255, and DT4256) optimized for specific field applications; and pocket models (DT4221, DT4222, DT4223, and DT4224) built around a compact body for ergonomic hold and a reliable, safe design. A dedicated measurement IC developed in-house gives the series its measurement-speed engine.

Application coverage spans both field electrical work and laboratory and R&D use. The DT4200 can accurately measure the output voltage on the secondary side of an inverter, isolating the fundamental wave with its low-pass filter to reject harmonic components. High-end models provide a DC microamp range for measuring burner flame currents in gas-burning devices, and the DT4254 can measure DC voltages up to 1700 V for no-load voltage inspections of megasolar installations. Other supported tasks include 4 to 20 mA instrumentation signal measurement with percentage-equivalent display, ripple voltage confirmation of DC charging systems, and voltage measurement at distribution panels and service wires.

ValueTronics keeps the instruments it sells in its own 20,000 sq ft secure warehouse at 1675 Cambridge Drive in Elgin, Illinois, holding inventory on hand rather than sourcing it on demand. That combination of held stock and verified condition is what backs each order.

Compare Other Models in This Series

The Hioki DT4200 series is a family of digital multimeters offered in three groups. The high-end DT4281 and DT4282 are positioned for high accuracy and a broad range of measurement parameters, with the DT4281 designed for field current measurement using clamp-on sensors and the DT4282 designed for laboratory and R&D use across many parameters. The standard DT4252 through DT4256 are field-optimized instruments chosen by application, and the pocket DT4221 through DT4224 pair a compact body with a safe design.

Within the pocket group, the DT4221 and DT4223 are aimed at workers whose principal use is voltage measurement, while the DT4222 and DT4224 add parameters for laboratory and R&D use. The DT4223 and DT4224 are the models that introduce the series' circuit breaker false trip prevention function.

Each model linked below is its own dedicated product page with condition-matched pricing for the new unit. Select the specific model that matches your required measurement parameters and category rating, and review that page for its own specifications and availability.

The clearest differences across the family are accuracy, safety category, and supported parameters. Typical DC voltage accuracy improves from ±0.5% rdg. ±5 dgt. on the pocket models to ±0.3% rdg. ±3 dgt. on the standard models and ±0.025% rdg. ±2 dgt. on the high-end DT4281/DT4282. Measurement categories are CAT III (1000 V)/CAT IV (600 V) on the standard and high-end models and CAT III (600 V)/CAT IV (300 V) on the pocket models. The comparison table below lists each model's ranges and supported functions.

Parameter support also varies by model, as the comparison table shows. AC clamp-on current measurement is available on the DT4281, DT4253, DT4255, and DT4256; conductance is provided on the DT4282; and the DT4254 extends DC voltage measurement to 1700 V for megasolar no-load voltage inspection. Circuit breaker false trip prevention is listed for the DT4223 and DT4224. Confirm each model's own row before selecting, since the available functions differ from model to model.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Accessories Supplied

• TEST LEAD DT4911
• Instruction Manual
• LR03 Alkaline battery ×1
• Holster (attached to the instrument, with a test lead holder)

Product Core & Specifications

Important: DT4254 can measure voltages in excess of 1000 V DC only if both conditions are satisfied: the circuit under measurement is isolated from the commercial power grid, and the circuit under measurement is isolated from ground.

Important: Model DT4254 can measure DC voltages up to 1700 V, enabling no-load voltage inspections of megasolar installations, subject to the isolation conditions above.

Important: AC clamp-on current measurement on the DT4281, DT4253, DT4255, and DT4256 requires an optional clamp-on probe (9010-50, 9018-50, or 9132-50) and the Conversion Adapter 9704; these are not included with the instrument.

Important: USB communication requires the optional DT4900-01 Communication Package (not included).

Important: Temperature measurement (DT4281, DT4282, DT4253) requires the optional K Thermocouple DT4910, which is not included.

Important: The optional Connection Cable L4930 is required in order to use the probe tips shown for the DT4250 / DT4280 Series.

Important: IEC 61010 classifies measurement locations into safety-based categories (CAT II to CAT IV); using an instrument that does not satisfy the required safety level can lead to an electrical accident — select a model whose measurement category suits the location of use.

About this New unit

This is a brand-new, factory-sealed unit, supplied exactly as it arrives from the manufacturer and backed by the full manufacturer warranty. For the exact configuration, available options, included accessories, or current lead time for your application, our Test Architects can confirm the details before you order.

ValueTronics supplies both new and used test and measurement equipment. New units ship factory-sealed, exactly as received from the manufacturer; every used unit is inspected and functionally verified in-house at our 20,000 sq ft secure facility in Elgin, Illinois before it ships. Our Test Architects can help you select the condition, calibration, and configuration that fit your application.

Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.