# Keysight U1241B 10,000 Count True RMS Handheld Digital Multimeter # Keysight U1241B 10,000 Count True RMS Handheld Digital Multimeter ## Key Features At A Glance - 10,000-count display with true RMS AC voltage and current measurement - 0.09% basic DC voltage accuracy - Measures ACV, DCV, ACI, DCI, resistance, frequency, diode, continuity, capacitance, and temperature - CAT III 1000 V and CAT IV 600 V overvoltage protection; certified to CE and CSA standards - Advanced functions include capacitance, temperature, and MIN/MAX recording - Built-in switch counter; harmonic ratio and dual/differential temperature on the U1242B - Adjustable backlighting with two intensity levels and overmold body casing - Optional IR connectivity bracket (U1179A) for Bluetooth or USB data transfer The Keysight U1240B Series handheld digital multimeters are designed to let you check more with wider measurement ranges, delivering true RMS readings on 10,000-count displays. The series is represented by two current models, the U1241B and U1242B, housed in high-visibility orange cases. Each meter combines core electrical measurement with advanced, maintenance-oriented functions accessed at the press of a button. These handheld meters are built to simplify maintenance work. Built-in capabilities such as the switch counter, harmonic ratio, and dual and differential temperature measurement are intended to streamline maintenance tasks, while adjustable backlighting lets you complete jobs in subdued lighting conditions or prolong battery life. As a handheld true RMS multimeter, the instrument covers everyday electrical diagnostics across voltage, current, resistance, frequency, diode, and continuity testing. ValueTronics stocks and holds its own inventory in a 20,000 square foot secure warehouse at 1675 Cambridge Drive in Elgin, Illinois. ## Brand Heritage Keysight Technologies traces its measurement heritage to Hewlett-Packard. The test and measurement business was spun off as Agilent Technologies in 1999 and subsequently established as Keysight Technologies in 2014. ## Compare Other Models in This Series The U1240B Series brings together handheld digital multimeters that share a common measurement architecture: true RMS AC measurement, 10,000-count displays, and CAT III 1000 V / CAT IV 600 V overvoltage protection. The two current models, the U1241B and U1242B, are presented in vivid orange cases and share the same core functions of ACV, DCV, ACI, DCI, resistance, frequency, diode, and continuity testing. Across the series, advanced functions such as capacitance measurement, temperature measurement, and MIN/MAX recording are complemented by maintenance features like the built-in switch counter. The models differ primarily in the set of advanced logging and temperature functions they include, as detailed in the comparison below. Each new model below is its own dedicated product page with condition-matched pricing, so you can compare the U1241B and U1242B and select the exact set of functions your work requires. The principal differences within the series lie in advanced logging and temperature functions. The U1242B adds manual data logging, harmonic ratio measurement, and dual/differential (T1–T2) temperature capability, which are specified for the U1242B only and do not appear on the U1241B. Both models support K-type thermocouple measurement from –40 to 1000 °C, while J-type thermocouple support is specified for the U1242B only. The comparison table that follows summarizes which functions are available on each model so you can match the meter to your maintenance and measurement needs. Model Manual Data Logging Harmonic Ratio Dual/Differential Temperature **U1241B** No No No U1242B Yes Yes Yes Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below. ## Accessories Supplied - Four 1.5 V AAA alkaline batteries - Certificate of Calibration (CoC) - Test probe leads (4-mm tips) - Quick Start Guide - Free test data (Option UK6) ## Product Core & Specifications Specification Value DC Voltage Accuracy ±(% of reading + counts) \[Input impedance: 10 MΩ nominal\] 1000.0 mV range (0.1 mV) 0.09% + 5 10.000 V range (0.001 V) 0.09% + 2 100.00 V range (0.01 V) 0.09% + 2 1000.0 V range (0.1 V) 0.15% + 5 DC Current Accuracy ±(% of reading + counts) 1000.0 µA range (0.1 µA), burden < 0.06 V (50 Ω) 0.1% + 3 10000 µA range (1 µA), burden < 0.55 V (50 Ω) 0.1% + 3 100.00 mA range (0.01 mA), burden < 0.18 V (0.5 Ω) 0.2% + 3 440.0 mA range (0.1 mA), burden < 0.8 V (0.5 Ω) 0.5% + 3 10.000 A range (0.001 A), burden < 0.4 V (0.01 Ω) 0.6% + 5 Resistance Accuracy ±(% of reading + counts) 1000.0 Ω range (0.1 Ω), test current 0.5 mA 0.3% + 3 10.000 kΩ range (0.001 kΩ), test current 50 µA 0.3% + 3 100.00 kΩ range (0.01 kΩ), test current 4.91 µA 0.3% + 3 1000.0 kΩ range (0.1 kΩ), test current 447 nA 0.3% + 3 10.000 MΩ range (0.001 MΩ), test current 112 nA 0.8% + 3 100.00 MΩ range (0.01 MΩ), test current 112 nA 1.5% + 3 Diode Test Accuracy ±(% of reading + counts) 1 V range (0.001 V), approximately 0.5 mA 0.3% + 2 AC Voltage Accuracy ±(% of reading + counts), True RMS, AC coupled (valid 5% to 100% of range) 1000.0 mV range (0.1 mV) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 2% + 5 10.000 V range (0.001 V) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 2% + 5 100.00 V range (0.01 V) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 2% + 5 1000.0 V range (0.1 V) 40 to 500 Hz: 1% + 5 AC Current Accuracy ±(% of reading + counts), True RMS, AC coupled (valid 5% to 100% of range) 1000.0 µA range (0.1 µA), burden < 0.06 V (50 Ω) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 1.5% + 5 10000 µA range (1 µA), burden < 0.55 V (50 Ω) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 1.5% + 5 100.00 mA range (0.01 mA), burden < 0.18 V (0.5 Ω) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 1.5% + 5 440.0 mA range (0.1 mA), burden < 0.8 V (0.5 Ω) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 1.5% + 5 10.000 A range (0.001 A), burden < 0.4 V (0.01 Ω) 40 to 500 Hz: 1% + 5; 500 Hz to 1 kHz: 1.5% + 5 Temperature Accuracy ±(% of reading + offset error) K-type (for U1241B and U1242B), –40 to 1000 ºC / –48 to 1832 ºF (0.1 °C / 0.1 °F) 1% + 1 ºC / 1% + 1.8 °F J-type (for U1242B only), –40 to 1000 ºC / –48 to 1832 ºF (0.1 ºC / 0.1 ºF) 1% + 1 ºC / 1% + 1.8 °F Capacitance Accuracy ±(% of reading + counts) 1000.0 nF range (0.1 nF) 1.2% + 4 10.000 µF range (0.001 µF) 1.2% + 4 100.00 µF range (0.01 µF) 1.2% + 4 1000.0 µF range (0.1 µF) 2% + 4 10.000 mF range (0.001 mF) 2% + 4 Harmonic Ratio (U1242B only) Range 0.0% to 99.9% Frequency 40 to 500 Hz Voltage 100 mVAC to 1000 VAC Switch Counter Low level (Normally close), display "Lo", switch threshold < 370 ohms Counts low-to-high transition High level (Normally open), display "Hi", switch threshold > 430 ohms Counts high-to-low transition Test current 0.5 mA, maximum open circuit voltage 2.8 V Detects intermittent Opens or Closes lasting at least 250 µsec; maximum count reading 199.99 M Frequency Accuracy 100.00 Hz range (0.01 Hz) 0.03% + 3 1000.0 Hz range (0.1 Hz) 0.03% + 3 10.000 kHz range (0.001 kHz) 0.03% + 3 100.00 kHz range (0.01 kHz) 0.03% + 3 1000.0 kHz range (0.1 kHz) 0.03% + 3 (effective frequency measurement up to 200 kHz) Minimum input frequency 1 Hz Frequency Sensitivity During Voltage Measurement (minimum RMS sine wave) 1000.0 mV range 20 Hz to 50 kHz: 0.3 V; 50 to 200 kHz: 0.6 V 10.000 V range 20 Hz to 50 kHz: 0.5 V; 50 to 200 kHz: 1.8 V 100.00 V range 20 Hz to 50 kHz: 5 V; 50 to 200 kHz: 10 V (< 100 kHz) 1000.0 V range 20 Hz to 50 kHz: 50 V; 50 to 200 kHz: 100 V (< 100 kHz) Frequency Sensitivity During Current Measurement (20 Hz to 20 kHz, minimum RMS sine wave) 1000.0 µA range 100 µA 10000 µA range 500 µA 100.00 mA range 10 mA 440.00 mA range 50 mA 10.000 A range 1 A Measuring Rate (Times/second) ACV 7 DCV (V or mV) 7 Ω 14 Diode 14 Capacitance 4 (< 100 µF) DCA (µA, mA, A) 7 ACA (µA, mA, A) 7 Temperature 7 (single) Frequency 1 (> 10 Hz) General Specifications Display Dual display (secondary display intended for temperature function display only) consisting of 4-digit liquid crystal display (LCD) with maximum reading of 11,000 counts. Automatic polarity indication. Power consumption 0.22 VA maximum Battery type and life Four single standard 1.5 V AAA batteries (Alkaline or Zinc Chloride type); 300 hours typical Operating environment Full accuracy at –10 to 55 °C; and to 80% RH for temperatures up to 30 °C, decreasing linearly to 50% RH at 55 °C; 0 to 2000 meters per IEC 61010-1 3rd edition CAT III 1000 V / CAT IV 600 V Storage compliance –20 to 70 °C Safety compliance IEC 61010-1:2010 / EN 61010-1:2010, IEC 61010-2-033:2012 / EN 61010-2-033:2012; CAN/CSA-C22.2 No.61010-1-12, CAN/CSA-C22.2 No. 61010-2-033-12; ANSI/UL Std. No. 61010-1 (3rd Edition), ANSI/UL Std. No. 61010-2-033 (1st Edition) Measurement category CAT III 1000 V / CAT IV 600 V Overvoltage Protection, Pollution Degree 2 EMC compliance Commercial limits compliance with EN61326-1; influence of radiated immunity: RF electromagnetic fields of 3 V/M Common Mode Rejection Ratio (CMRR) \> 90 dB at DC, 50/60 Hz ± 0.1% (1 kΩ unbalanced) Normal Mode Rejection Ratio (NMRR) \> 60 dB at 50/60 Hz ± 0.1% > **Important:** Current can be measured up to 10 A continuously at a maximum operating temperature of 50 °C. After measuring a current greater than 10 A, leave the meter to cool down for 60 seconds before applying a low-current measurement. > **Important:** After measuring a current above 440 mA, allow the meter to cool down for twice the measuring time used before applying a low-current measurement. > **Important:** Diode test overload protection: 1000 V RMS for circuits < 0.3 A short circuit current. > **Important:** If used in close proximity to an RF transmitter or when subjected to continuously present electromagnetic phenomena, some recoverable degradation of performance may occur. > Recommended pairing: the Keysight U1583B AC current clamp (dual-range 40 A and 400 A) connects through its included BNC-to-banana-plug adapter to extend AC current measurement. ## 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.** ## Details - **Price:** 384.0 USD - **Vendor:** Keysight Technologies - **Type:** Multi Met - **Tags:** Keysight, Keysight Technologies, Manufacturers, Meters & DAQ, Multimeter, product_manual_group_3, Product_new ## Variants | Variant | Price | Available | |---------|-------|-----------| | Default Title | 384.00 USD | In stock | ## Images - U1241B Keysight Technologies Multimeter --- > Source: [ValueTronics](https://valuetronics.com/products/u1241b-keysight-multimeter-new) > Updated: 2026-06-20