EEVBlog 121GW Multimeter

Available at EEVBlog and eBay

Designed for electronics use, with unique features such as:

  • Bluetooth connectivity (multi-device capability)
  • Open Source Cross Platform application software (Android + Windows, and more soon)
  • 15V Diode Test Voltage (useful for Zeners + LED strings etc)
  • VA Power measurement
  • Low Burden™ voltage
  • Unique burden voltage display
  • Micro SD Card data logging + firmware updating

Other major features include:

  • Dual 50,000 count display with bargraph
  • 0.05% + 5 Basic DCV Accuracy
  • Auto-Hold measurement
  • 600V CAT-III with independent UL 61010 certification by ETL
  • Safe operation through HRC fuse + TVS + PTC + MOV + Diode Bridge protection

Hardware Features:

  • AD8436 >100KHz True RMS
  • 4 x AA battery powered with 500+ hr battery life
  • Compact design – 84 × 165 × 59 mm (W × L × H)
  • Hackable ST ARM Cortex M3 processor (S-LINK/V2 programmer interface inside)
  • Hycon HY3131 chipset
  • MAX4238 Low Offset Amplifier for current ranges
  • SD Card firmware update
  • Full Open Schematic available
  • 8ppm ADR3412 voltage reference

The meter is manufactured by UEI Test Instruments, a reputable US based designer and manufacturer of high quality test gear. The design work was primarily done by UEI, but with a great deal of design input and direction from Dave. The meter is manufactured in South Korea.

NOTE: The current stock meter from this website is the latest post-Kickstarter build that has the new late 2019 PCB (doesn’t require the shim) and larger protection transistors fitted. It also comes with the UEi test leads instead of the Brymen test leads. These leads do not have banana tip adapters like the Brymen leads but are still top quality silicone leads.