1. Introduction
The RD UM25 and UM25C are advanced USB meter testers designed to accurately measure and monitor various electrical parameters of USB-powered devices and chargers. These devices are essential tools for evaluating charging performance, identifying faulty cables, and understanding power consumption. The UM25C model includes Bluetooth connectivity for app and PC software control.
Image 1.1: RD UM25C USB Meter Tester displaying real-time voltage and current measurements.
2. Key Features
- Voltage Measurement: Range of 4-24.000V with 0.001V resolution.
- Current Measurement: Range of 0-5.0000A with 0.0001A resolution.
- Quick Charge Recognition: Supports QC2.0, QC3.0, APPLE 2.4A/2.1A/1A/0.5A, Android DCP, and SAMSUNG protocols.
- 1.44-inch IPS HD Color Screen: Provides clear, real-time display of charging status and parameters.
- Capacity and Energy Detection: Accumulates mAh and mWh values.
- Load Impedance Measurement: Measures from 0.8Ω to 9999.9Ω.
- Temperature Measurement: Range of -10°C to 100°C (0°F to 200°F).
- Data Storage: Ability to store measurement data.
- Multi-language Setting: Supports various languages for user interface.
- Bluetooth Connectivity (UM25C only): Connects to mobile app (Android/iOS) and PC software for remote control and data analysis.
Image 2.1: Overview of the UM25/UM25C's primary features.
3. Package Contents
Upon opening the package, verify that all items are present and in good condition:
- RD UM25C USB Meter Tester
- Instruction Card (often includes QR code for digital manual/software)
- Protective Tin Box
Image 3.1: The UM25C USB Meter Tester and its protective tin packaging.
4. Product Overview
Familiarize yourself with the various ports and buttons on the UM25/UM25C device:
Image 4.1: Detailed view of the UM25/UM25C ports and controls.
- USB A Male Port: Connects to the power source (e.g., charger, power bank).
- USB A Female Port: Connects to the device being charged/tested.
- Type-C IN: USB-C input port.
- Type-C OUT: USB-C output port.
- Micro USB: For connecting to PC for software control (UM25C only).
- Bluetooth Switch: Activates/deactivates Bluetooth for app connectivity (UM25C only).
- Buttons: Used for navigating menus, changing display modes, and adjusting settings.
5. Setup and Basic Connection
To begin using your UM25/UM25C USB Meter Tester, follow these steps:
- Connect the USB A Male port of the UM25/UM25C to your power source (e.g., USB wall charger, power bank, computer USB port).
- Connect your device's charging cable to the USB A Female port or the Type-C OUT port of the UM25/UM25C.
- Connect the other end of the charging cable to your device (e.g., smartphone, tablet).
- The display will illuminate, showing real-time voltage, current, and other parameters.
Important: Ensure correct orientation when connecting. Incorrect connection can prevent proper operation.
Image 5.1: Correct and incorrect connection methods for the USB Meter Tester.
6. Operating Instructions
6.1. Display Modes and Navigation
The UM25/UM25C features multiple display interfaces to show different data. Use the physical buttons (PREV/NEXT) on the device to cycle through these screens:
- Measurement Main Interface: Displays real-time voltage, current, power, capacity, and energy.
- Wire Impedance Measurement Interface: For measuring cable resistance.
- Measurement Graphing Interface: Shows real-time voltage and current curves.
- Charging Recording Interface: Records charging data over time.
- System Parameter Setting Interface: Allows adjustment of brightness, temperature units, and other settings.
Image 6.1: Examples of different display interfaces and the hidden language selection menu.
6.2. Hidden Interface (Language Selection)
To access the hidden interface for language selection or factory reset:
- Power off the module.
- Press and hold any button while powering on the module.
- Three options will appear: 1. Chinese, 2. English, 3. Reset.
- Use the buttons to select your desired option. Note that a factory reset will clear all stored data.
6.3. App and PC Software Control (UM25C Only)
The UM25C model offers enhanced functionality through its dedicated mobile application (Android/iOS) and PC software. This allows for real-time data display, operation, and data export.
Image 6.2: UM25C App and PC Software interfaces for data monitoring and control.
Mobile App (Android + iOS)
Connect the app via Bluetooth to view real-time testing data such as Voltage, Current, Power, and Resistance. Most functions can be operated directly from the app.
- Compatibility: Android 5.0 and above, iOS 8.0 and above.
- Download: Refer to the instruction card for QR codes or search for "UM_Meter" in your device's app store.
PC Software (Windows 7 and above)
The PC software connects via Bluetooth (UM25C) or Micro USB (UM25C) and provides real-time Voltage, Current, Power, and other data. It also supports exporting data to Excel for detailed analysis.
- Compatibility: Windows 7 and above.
- Download: Refer to the instruction card or manufacturer's website for software download links.
6.4. Official Product Video
Video 6.1: An official product video demonstrating the features and usage of the UM25/UM25C USB Meter Tester, including its packaging, various display modes, and connectivity with the mobile application and PC software.
7. Technical Specifications
The following table details the technical indicators for the RD UM25 and UM25C USB Meter Testers:
Image 7.1: Technical specifications of the UM25/UM25C USB Meter Tester.
| Parameter | Specification |
|---|---|
| Model | UM25 / UM25C |
| Display Screen | 1.44 inch color LCD display |
| Voltage Measurement Range | 4-24.000V |
| Voltage Measurement Resolution | 0.001V |
| Voltage Measurement Accuracy | ±(0.5‰+2digit) |
| Current Measurement Range | 0-5.0000A |
| Current Measurement Resolution | 0.0001A |
| Current Measurement Accuracy | ±(1‰+4digit) |
| Capacity Accumulation Range | 0-99999mAh |
| Energy Accumulation Range | 0-99999mWh |
| Load Impedance Range | 0.8Ω-9999.9Ω |
| Temperature Range | -10°C~100°C / 0°F~200°F |
| Temperature Measurement Error | ±3°C / ±6°F |
| Screen Brightness Setting | Levels 0-5 |
| Delay Off Screen Time | 0-9 minutes |
| Dimensions | UM25: 71.2mm x 30.5mm x 11.3mm UM25C: 71.2mm x 30.5mm x 12.4mm |
| Product Weight | UM25: 50g UM25C: 54g (with packaging) |
| Quick Charge Recognition Mode | QC2.0, QC3.0, APPLE 2.4A/2.1A/1A/0.5A, Android DCP, SAMSUNG |
8. Troubleshooting
- Device Reboots During Fast Charging: If the tester reboots or cycles when fast charging a device, especially at higher currents (e.g., above 2.5A), ensure your power source and cables are capable of delivering the required current stably. While rated for 5A, some devices may exhibit instability with certain fast-charging protocols or power sources at peak loads. Try a different cable or power adapter to isolate the issue.
- No Display/No Power: Ensure the USB A Male port is fully inserted into a working power source. Check the cable connecting the power source to the tester.
- Inaccurate Readings: Verify that all connections are secure. If readings seem consistently off, perform a factory reset via the hidden interface (Section 6.2). If the issue persists, contact support.
- Bluetooth Connection Issues (UM25C): Ensure the Bluetooth switch is enabled. Check your mobile device's Bluetooth settings and ensure the UM25C is discoverable. Restart both the tester and your mobile device.
9. Care and Maintenance
- Cleaning: Use a soft, dry cloth to clean the device. Avoid using liquid cleaners or solvents.
- Storage: Store the device in its protective tin box in a cool, dry place when not in use.
- Handling: Avoid dropping the device or subjecting it to strong impacts. Be gentle when plugging and unplugging cables to prevent damage to the ports.
- Protective Film: The screen may have a protective film. This can be carefully peeled off for clearer viewing.
10. Warranty and Support
For warranty information, technical support, or service inquiries, please refer to the documentation provided with your purchase or contact the seller directly. You can also visit the official RD Store for additional resources: