For a multimeter, the Plugable USB-C amperage and voltage tester (USBC-VAMETER3) manages to fit a lot of useful features into a sturdy little package. About the size of a USB flash drive, this bidirectional USB tester allows for full USB data passthrough while it monitors USB-C power and charging, measures voltage and amperage, and visualizes the directional flow of electrical current—all in real time.

Connect the USBC-VAMETER3 inline between a USB-C host system like a laptop, tablet, or cell phone and a charger to use it as a USB voltage meter or power consumption meter. An updated OLED screen means a brighter and easier-to-read display in any lighting conditions, and a new orientation button lets you flip the screen with a click.

How it works: This meter is a transparent interposer—it should not interfere with the USB data (1.1 through 3.1 Gen 2), USB-C Alternate Mode video, or USB-C charging. The meter can be used in-line with USB-C docking stations, chargers, and other USB-C accessories. The meter achieves this without interfering with normal USB-C operation as it only taps into the power (VBUS) and ground connections to measure values and leaves the data lines untouched.

Common uses:

• Connecting between a USB-C host system like a laptop, tablet, or cell phone and a charger to monitor charge information.
• Connecting between a USB-C host and docking station to monitor charge information.
• Connecting between a USB-C host system and a USB-C bus powered accessory like an external hard drive or flash drive to measure power draw of a device.
• Testing for USB-C port spec compliance such as a VBUS hot condition, voltage drop under load, etc.