Hioki DT4222 Pocket Digital Multimeter

Key Features At A Glance

• True RMS measurement across the series for accurate readings on distorted current and voltage waveforms
• Hioki in-house custom ASIC delivers a stable reading in about half a second (nearly 0.6 s) from probe contact
• Rubber-bumpered design endures a 1-meter drop onto concrete; dust-resistant (IP40 to IP42 across the series)
• Safety ratings span CAT III 600V/CAT IV 300V up to CAT III 1000V/CAT IV 600V across the series
• Select models omit the current terminal and use a clamp-on sensor to enhance operator safety
• Bright white LED backlight with wide-viewing-angle display for clear readings in dark work areas
• Bright LED backlight for dark worksites (red LED backlight on High-End models)
• Optional USB communication via the DT4900-01 Communication Package for PC data transfer
• Optional DT4900-01 USB Communication Package with an optically isolated PC link for data logging
• Low-pass filtering for stable measurement in electrically noisy environments such as inverter systems

The Hioki DT4200 Series is a family of handheld digital multimeters built around an in-house custom ASIC that Hioki developed to deliver what it describes as the world's fastest DMM measurement engine, reaching a stable reading in about half a second — nearly 0.6 seconds — from probe contact to display. The series spans high-end (DT4281, DT4282), standard (DT4251, DT4252, DT4253), and pocket (DT4221, DT4222) models, each using the True RMS method for accurate measurement of distorted current and voltage waveforms.

Across the series, the models are positioned for tasks named in the lineup: electrical work and power line applications, laboratory and R&D measurement, and instrumentation, air-conditioning, and gas-equipment work. The DT4281 is described as optimized for inverter system measurements and for checking ripple voltage in DC supply systems, while its DC microampere range suits burner flame-current inspection. The high-end models also support on-the-spot storage of battery cell voltage to improve the efficiency of UPS maintenance.

ValueTronics stocks and holds the DT4200 Series in our own 20,000-square-foot secure warehouse at 1675 Cambridge Drive in Elgin, Illinois.

Compare Other Models in This Series

The DT4200 Series is organized into three groups that the lineup labels High-End, Standard, and Pocket. The High-End group comprises the DT4281 and DT4282; the Standard group the DT4251, DT4252, and DT4253; and the Pocket group the DT4221 and DT4222. All models share the True RMS measurement method and Hioki's fast-response measurement engine.

Within each group, individual models are differentiated by their measurement parameter sets, accuracy class, and the way current is handled — some include direct current terminals, while others omit them in favor of a clamp-on sensor connection. The selection guide matches each model to a measurement situation rather than ranking them on a single scale.

Each model below links to its own dedicated product page with condition-matched pricing for the new unit you select. Choose the model that matches your measurement parameters and safety-category needs, then review that page for its specific specifications and availability.

The DT4281 sits at the top of the series with a DC voltage basic accuracy of ±0.025% rdg. ±2 dgt. and a 630 Hz analog low-pass filter that cuts harmonics for inverter-system measurement, along with 15 times better noise immunity than former models. It adds DCV+ACV and peak measurement functions, decibel and percentage conversion, internal storage of up to 400 data points, and an AC clamp range of 10 A to 1000 A using an optional clamp-on probe. Unlike the DT4282, it does not provide the direct 6 A and 10 A current ranges.

The clearest differences across the series are measurement breadth, accuracy, and safety category. The High-End and Standard models are rated CAT III 1000V / CAT IV 600V, while the Pocket models are rated CAT III 600V / CAT IV 300V. DC voltage basic accuracy tightens from ±0.5% rdg. ±5 dgt. on the Pocket models to ±0.3% rdg. ±5 dgt. on the Standard models and ±0.025% rdg. ±2 dgt. on the High-End models.

Current handling is the other major divider, as the comparison table that follows details. The DT4282 and DT4252 provide direct 6 A and 10 A ranges; the DT4281, DT4251, and DT4253 accept optional clamp-on probes for AC current up to 1000 A; the DT4253 adds a 60 µA to 60 mA range for instrumentation work; and several models — including the DT4221, DT4222, and DT4251 — omit a directly accessible current terminal to enhance operator safety. Functions such as temperature, capacitance, conductance, and voltage detection are present on some models and absent on others, as each model's row in the table shows.

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: Accidentally measuring voltage with the low input impedance of a current measurement range may cause inadvertent breaker trips, short circuits, or fire hazards.

Important: AC Clamp (AC Current) measurement requires the optional 9010-50, 9018-50, or 9132-50 CLAMP ON PROBE (Adapter Model 9704 is required to connect these probes to the DT4281, DT4251, and DT4253). Accuracy specifications do not include the error of the clamp-on probe.

Important: Temperature measurement uses the optional K Thermocouple DT4910 (DT4281, DT4282, DT4253). Accuracy does not include the error of the K thermocouple.

Important: USB communication requires the optional DT4900-01 Communication Package (footnote *1, applicable to DT4281, DT4282, DT4251, DT4252).

Important: Continuous operating time of approx. 100 hours for the DT4280 Series is specified when using four AA alkaline batteries.

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.