Joy-it JT-UM120 USB Multimeter User Manual

1. Introduction

Welcome to the user manual for your Joy-it JT-UM120 USB Multimeter. This device is designed to provide comprehensive measurement capabilities for various USB power parameters, ensuring you can monitor and analyze the quality and performance of your USB connections and devices.

Key features include:

• Real-time monitoring: Voltage, current, power, and energy.
• Fast-charging protocol support: Compatibility with various fast-charging standards.
• PC software: For detailed data analysis, logging, and graphing.
• Automatic display rotation: For convenient viewing in any orientation.
• Cable resistance measurement: To assess cable quality.

2. Product Overview

The JT-UM120 features a compact design with a 2.0" IPS color display for clear data visualization. It includes multiple USB input and output ports for versatile connectivity.

2.1 Device Components

This image shows the multimeter's main screen, displaying real-time measurements such as VBUS (voltage), IBUS (current), and PBUS (power), along with other statistics and protocol information.

This image illustrates the control interface of the multimeter, including the Micro-USB port for PC connection, the 'OK' button for selection, a rotary encoder for navigation, and a 'BACK' button for returning to previous menus.

This image displays the connectivity options on the multimeter's bottom side, including USB-C input, Micro-USB output, USB-C output, and a switch for Power Delivery (PD) communication.

This image offers an angled view of the multimeter, showcasing its vibrant display and overall design, with current measurements visible.

3. Setup

3.1 Initial Connection

To begin using your JT-UM120 USB Multimeter, simply connect it in-line with the USB device and power source you wish to measure.

1. Connect the USB power source (e.g., wall charger, power bank) to one of the input ports on the JT-UM120 (USB-A, USB-C, or Micro-USB IN).
2. Connect your device (e.g., smartphone, tablet) to one of the output ports on the JT-UM120 (USB-A or USB-C OUT).
3. The display will automatically power on and begin showing real-time measurement data.

3.2 PC Software Installation (Optional)

For advanced data logging, analysis, and firmware updates, you can install the dedicated PC software.

1. Download the latest software from the official Joy-it website (refer to product page or included documentation for URL).
2. Install the software on your Windows PC.
3. Connect the JT-UM120 to your PC using the Micro-USB PC-Interface port.
4. Launch the software and follow the on-screen instructions to establish a connection with the multimeter.

4. Operating Instructions

4.1 Navigating the Display

The JT-UM120 features a 2.0" IPS color display with automatic orientation rotation. Use the navigation wheel and 'OK' button to browse through different measurement views and settings.

• Main Measurement Screen: Displays real-time voltage (VBUS), current (IBUS), and power (PBUS).
• Detailed Measurement Screen: Provides more granular data, including energy (Wh), capacity (Ah), internal resistance, and ripple.
• Real-time Graph View: Visualizes voltage and current trends over time.
• Protocol Detection: Shows detected fast-charging protocols (e.g., QC2.0, PD3.0).

4.2 Data Measurement Groups

The device supports up to 10 data measurement groups, allowing you to store and compare different measurement sessions.

• To switch between groups: Navigate to the data group menu using the navigation wheel.
• To clear a group: Select the desired group and choose the 'Clear' option.

4.3 Fast Charge Trigger

The JT-UM120 includes a fast-charge trigger function for testing compatibility with various fast-charging protocols.

• Access the trigger menu from the main interface.
• Select the desired protocol (e.g., QC3.0, PD) and voltage/current settings.
• Observe the device's response to the triggered protocol.

4.4 Cable Resistance Measurement

This function helps assess the quality of USB cables by measuring their internal resistance.

1. Connect the multimeter to a power source.
2. Connect the cable to be tested to the output port.
3. Follow the on-screen instructions to perform the measurement. The device will prompt you to connect a load.

5. Maintenance

5.1 Cleaning

Clean the device with a soft, dry cloth. Do not use abrasive cleaners or solvents.

5.2 Storage

Store the multimeter in a cool, dry place away from direct sunlight and extreme temperatures.

5.3 Firmware Updates

Periodically check the Joy-it website for firmware updates to ensure optimal performance and access to new features. Updates are typically performed via the PC software.

6. Troubleshooting

6.1 Display Not Turning On

• Ensure the multimeter is properly connected to a functioning USB power source.
• Check if the power source provides sufficient voltage (4-28V).

6.2 Inaccurate Readings

• Verify that all connections are secure.
• Ensure the connected load is within the specified measurement ranges.
• Try a different USB cable or power source.
• Perform a factory reset if available in the settings menu.

6.3 PC Software Connection Issues

• Confirm the correct drivers are installed.
• Check the Micro-USB PC-Interface cable connection.
• Restart the PC software and the multimeter.

7. Specifications

8. Warranty and Support

For warranty information and technical support, please refer to the official Joy-it website or contact their customer service directly. Keep your purchase receipt as proof of purchase.

Manufacturer: Joy-it

Model: JT-UM120

Website: www.joy-it.net