Model 391B

390B Series

True RMS Handheld Digital Multimeter 40,000-count

Price: $488 / 3 yr Warranty

Name Qty Last Updated
SEFRAM 11 2026-02-24
NEWARK 2 2026-02-24
RS Europe 6 2026-02-24
TEST EQUIPMENT DEPOT (FOTRONIC) 2 2026-02-24

Overview

The 390B Series True RMS multimeters offer a comprehensive solution for general purpose measurement applications. Bundled with a complete set of accessories, these multimeters provide technicians and engineers with accurate results, data logging capabilities, and measurement features for evaluating a variety of electronics or electrical systems.

  • DCV, ACV, AC+DC, DCI, ACI, resistance, capacitance, frequency, diode, temperature, and continuity measurement functions
  • True RMS AC and AC+DC measurements
  • Bluetooth connectivity for live data monitoring and logging from a mobile device (Model 390B only)
  • Up to 100,000-count, dual display
  • dB, dBm, limits, peak-hold, REL (delta), MIN, MAX, and average math functions
  • HFR (High Frequency Rejection) mode applies a low pass filter for AC measurements (800 Hz cut-off)
  • Isolated USB interface with operating software for remote data logging
  • Dirt and water-resistant housing with rubberized protective case
  • CAT III 1000 V / CAT IV 600 V protection

Models

Product Display Count Ranging Correction Factor Interface MSRP
390B 40000 Auto True RMS USB, Bluetooth $572
391B 40000 Auto True RMS USB $488
393B 100000 Auto True RMS USB $615
394B 50000 Auto True RMS USB $837

Documents

Documentation

Software

391B_393B_Software.zip - version: 1.0.0
Operating Software
CP210X_USB_Driver.zip - version: V11.3.0
USB Virtual COM Drivers (Supports Windows 10/11)

Accessories

CP 3

AC/DC Clamp Accessory for DMMs

CP 3

  • Converts any DMM to a current clamp
  • Measures current without disconnecting circuit under test
  • Measures to 400A DC/AC
  • Outputs 1mV per Amp, operates on 2V range of any DMM
CP 3 Manual

MSRP: $113
PR 28A

40kV High Voltage DMM Probe

PR 28A

If the voltages you need to measure are above the specifications of the general purpose probe, B+K Precision has higher voltage probes for you.

  • 40,000VDC or 20,000Vac Max input voltage
  • X1000 Attenuation
  • 1000M ohms Input Impedance
  • 60Hz Bandwidth
  • 48" (1.2m) Cable Length

PR 28A Manual

MSRP: $122
SP201

Current transducer (10 mVAC/1 AAC, 200 A, Ø 15 mm)

SP201

  • Jaw opening 15 mm
  • Current transducer 200A AC
  • Output voltage 10mV AC/1A AC
  • Bandwidth 40 Hz to 5 KHz
  • Safety : for isolated conductor only

MSRP: $145
SP221

Current transducer (100 mVAC/1 AAC, 10A, Ø 15 mm)

SP221

  • Jaw opening 15 mm
  • Current transducer 10A AC
  • Output voltage 100mV AC/1A AC
  • Bandwidth 40 Hz to 5 KHz
  • Safety : for isolated conductor only

MSRP: $249
SP261

Current transducer (1 mVAC+DC/ 1AAC+DC, 1200 A, Ø 50 mm)

SP261

  • Jaw opening 50 mm
  • Current transducer 1200A
  • Output voltage 1mV/1A
  • Bandwidth DC A 3KHz
  • Safety : 600 V CAT III

MSRP: $535
SP270

Current transducer (1 mVAC/1 AAC, 2000 A, Ø 70 mm)

SP270

  • Current transducer up to 2000 A
  • Output voltage 1mV AC / 1A AC
  • Bandwidth 40 Hz to 5 KHz
  • Jaw opening 70 mm
  • Safety : 600 V CAT III

MSRP: $640
TL37

Red and Black CAT III (IV) 1000V (600V) Test Leads

TL37

Right-angled sheathed banana replacement 10A test leads for digital multimeters.

MSRP: $15
TL500B

High Performance Bench DMM Accessory Kit

TL500B

This kit of accessories was assembled to facilitate requirements by high-performance bench digital multimeters (DMM's) users. All the most popular accessories in one kit. The kit offers MiniProbe test probe, with spring-loaded tips, for fine probing; MiniPRO Test Clips for small and MiniFlex Test Clips for micro connections; and for those larger test points, both spade lug and banana plug adapters, two pairs of test leads for 4-wire measurements or calibration hookups, an insulated BNC male to sheathed banana jack adapter, and an insulated SMD Tweezer set for surface-mount component testing.

  • Silicone jacketed test lead wire with UL Listing
  • MiniProbes w/Spring loaded Stainless Steel Tips
  • Packaged in Plastic Case

 

Kit Contains:
(4) Test Lead 4mm Sheathed P-RaP Silicon 0.75,  40": (2) Black, (2) Red
(2) Spring Tip Mini-Probe-4mm Jack: (1) Black, (1) Red
(1) Insulated BNC male Adapt-4mm Safety Jacks
(2) Adapter 4mm Banana Plug to Jack: (1) Black, (1) Red
(2) Mini Flex Clip-4mm Jack-Silicon 0.40, 10 cm: (1) Black, (1) Red
(2) Adapter 6mm Spade 4mm-Jack: (1) Black, (1) Red
(2) Lead minipro-J-PVC 0.40, 10 cm: (1) Black, (1) Red
(1) Tweezer Test Lead Set- 4mm P, w/PVC pouch

Specifications

Temperature

-20 to +80 ºC

RoHS (2002/95/EC)

Compliant

MSRP: $278
TL50B

Maxi-Pro DMM Kit

TL50B

  • Complete accessory kit for all your testing needs.
  • Includes soft, flexible silicone lead wire easy movement and Tri-Fold Velcro Pouch for convenient storage.
  • 1000 V, CAT III (600 V, CAT IV)
  • UL Listed test leads
  • Silicone lead wire length 60" (1.5m)
  • Tri-fold Velcro Pouch

MSRP: $133