JOY-IT JT-UM25C USB Measurement Device
1. General Information
Thank you for choosing our product. The following outlines what to consider during initial setup.
USB ports are found not only on home PCs but also on power banks, in cars, and on trains. However, not all ports are of the best quality and deliver consistent currents and voltages. With the JT-UM25C, you can always keep an eye on all values. The measurement device supports additional functions such as Quickcharge 2.0 and 3.0, as well as Apple 2.4 A, 2.1 A, 1 A, 0.5 A, and Android DCP, and also offers convenient evaluation via a wireless interface. With a measuring range of up to 24 V and 5 A, the JT-UM25C is suitable for practically all applications. The integrated 1.44" LCD display can be adjusted in five brightness levels and always provides an overview of all measured values.
2. Device Overview
| Voltage Measurement Range | 4 - 24 V |
| Current Measurement Range | 0 - 5 A |
| Update Rate | 2 Hz |
| Measurement Accuracy | 0.001 V / 0.0001 A |
| Temperature Range | -10 - 100 °C |
| Display Size | 1.44" |
| Supported QuickCharge Modes | QC2.0, QC3.0, Apple 2.4 A / 2.1 A / 1 A / 0.5 A, Android DCP, Samsung |
Device Ports and Features:
- USB-A Port (female): For connecting devices.
- microUSB Port: For power input or data connection.
- 4x Multifunction Buttons: For navigation and control (PREV, NEXT).
- BT Switch: To activate Bluetooth functionality.
- USB-C Input: Supports VBUS, GND, CC1, CC2.
- 1.44" Color Display: Shows all measurement data.
- USB-C Output: Supports VBUS, GND, CC1, CC2.
- BT Status Indicator: Blinks when connecting, solid when connected.
3. Function Menus and Navigation
General Operation
Use the PREV and NEXT buttons to switch between menu pages.
- PREV: Press and hold to switch to the next data group.
- NEXT: Press and hold to return to the current data group.
Language Setting
To change the display language, disconnect the device from the power source. Then, press and hold any multifunction button while reconnecting the device. Continue holding the button until your desired language is displayed.
Menu Navigation Details
- Press to turn off display: Short press to turn the display off.
- Press and hold to rotate display counter-clockwise: Hold to rotate the display counter-clockwise.
- Press to open help menu: Short press to access the help menu.
- Press and hold to rotate display clockwise: Hold to rotate the display clockwise.
- Press to go to the previous page: Short press to navigate to the previous page.
- Press to go to the next page: Short press to navigate to the next page.
Main Menu (Measurement Results)
The main menu displays key measurements:
- Voltage: Current voltage reading.
- Current: Current amperage reading.
- Accumulated Electric Charge: Total charge in mAh.
- Temperature: Current temperature reading.
- Data Group: Indicates the current data group (1-9).
- Equivalent Resistance: Measured resistance.
- Power Consumption: Current power reading.
- Accumulated Energy: Total energy in mWh.
Data groups 1-9 are saved during a voltage interruption and resume upon reconnection. Data group 0 resets to zero after 1mAh is reached and is displayed blinking.
QuickCharge Detection
The device automatically detects devices with QuickCharge support. Supported modes include QC2.0, QC3.0, Apple 2.4 A / 2.1 A / 1 A / 0.5 A, Android DCP, and Samsung.
Charging Process Recording
The system automatically starts recording accumulated electric charge, energy, and elapsed time when the current exceeds a set trigger value. The "REC" indicator changes from red to green.
To adjust the trigger value: Hold the NEXT button to highlight the value, then press the PREV button to adjust. The value can be set between 0.01 A and 0.3 A.
Cable Impedance
Measurement Procedure:
- Connect the measurement device directly to the power source and set the current load (recommended: 1 A). Hold the NEXT button to start data recording.
- Disconnect the measurement device and reconnect it to the power source via a microUSB or Type-C data connection. Set the load current to the same value as in the first step. Hold the NEXT button to start data recording.
The prompt will stop blinking, and the cable resistance test is complete. The value will be displayed.
Caution: If the screen turns black in the second step, the voltage difference is too high, and the tester has switched to the 4V shutdown state. Reduce the load current. Restart the measurement from the first step. After the cable resistance test is completed, the tester must be turned off and on again to continue measurements.
Measurement Graph
This menu displays the voltage measurement over time (4-24V) and current measurement (0-5A), automatically adjusting the displayed range in real-time to account for voltage and current fluctuations.
- Hold NEXT to switch to the D+/D- graph. This displays D+/D- voltage measurements over time (0-3.3V), with automatic real-time range adjustment.
System Settings
Adjust settings such as:
- Time until automatic screen off: Default 1 minute.
- Display temperature: Default Celsius.
- Foreground color scheme: Default 6 (white).
- Screen brightness: Default Level 4.
- Background color scheme: Default 2 (blue).
Navigation within Settings:
- Hold NEXT to enter the settings mode.
- Press NEXT to navigate through options.
- Press PREV to change a setting.
- Press PREV again to cycle through adjustment options.
- Hold NEXT to exit the settings menu.
4. PC Software
1. Connection Setup
Download the software installation file from the provided link. You will also need the font package Arial Unicode MS.ttf, located in the same folder as the installation file. Install the font package first, then proceed with the software installation.
Follow the on-screen instructions during installation.
After installation, activate the BT function on the JT-UM25C using the BT switch. Use your computer's Bluetooth settings to search for new devices. Add the UM25C when found. If prompted for a PIN, use 1234 or 0000.
The screenshots shown are from Windows. Trademarks like Bluetooth or Windows belong to their respective owners.
To connect the installed software to the measurement device, you need to identify the COM port the device is connected to. In the Bluetooth connection overview, select "BT Settings". In the opened window, go to the "COM Ports" tab. The relevant interface is labeled "UM25C'Port'" in this case.
2. Using the Software
Open the UM25C PC Software V1.3. First, set the correct COM port to which the measurement device is connected and start the connection by clicking the "Connect" button.
The software displays various data, including voltage and current graphs, capacity, energy, voltage, current, power, impedance, and time records. You can rotate the screen, clear data, and export data.
Voltage & Current Graph: This graph visualizes voltage and current over time. Right-clicking within the graph provides options for auto-scaling the X-axis, copying data to the clipboard, exporting as an Excel file, exporting the current graph as an image, or deleting the current diagram.
Data Table: Displays detailed measurements for different data groups, including voltage, current, capacity, energy, power, impedance, and time.
Settings: Allows adjustment of brightness level, auto screen off time, and temperature display units (°C/°F).
Key Functions Overview (from Software Interface):
- Data Export
- Language Settings
- BT Connection
- General Information
- Voltage-Current Graph
- Accumulated mAh and mWh
- QuickCharge Detection, D+ and D- Data Voltage Signal
- Brightness and Temperature Adjustment
- Switch to next page
- Current Data Group Reset
- Display Rotation
- Switch to previous page
- Recording of Charging Process
- Main Measurement Values
5. Android App
Download and install the app installation file on your Android device. Note: The application is only compatible with Android 5.0 or higher.
Activate BT on the measurement device using the BT button and connect via your device's BT settings. Use PIN 0000 or 1234 for connection.
After installation and connection, you can start the application.
The app displays similar information to the PC software, including voltage and current graphs, detailed measurements, and settings for brightness and temperature.
6. Other Information
Information and Take-Back Obligations according to the Electrical and Electronic Equipment Act (ElektroG)
Symbol on Electrical and Electronic Equipment: The crossed-out trash can symbol indicates that electrical and electronic equipment should not be disposed of with household waste. Used equipment must be handed in at a collection point. Before disposal, separate any used batteries and accumulators that are not enclosed by the used equipment.
Return Options:
As an end-user, you can return your old equipment (which fulfills essentially the same function as the new one purchased from us) for disposal free of charge when buying a new device. Small devices with external dimensions not exceeding 25 cm can be returned in household quantities, regardless of whether a new device is purchased.
Return Option at our Company Location during Opening Hours:
SIMAC Electronics GmbH, Pascalstr. 8, D-47506 Neukirchen-Vluyn
Return Option Near You:
We will send you a package label to return the device to us free of charge. Please contact us via email at service@joy-it.net or by phone.
Packaging Information:
Please pack your old device securely for transport. If you do not have suitable packaging material or do not wish to use your own, please contact us, and we will provide you with suitable packaging.
7. Support
We are here for you even after your purchase. If you have any questions or encounter problems, we are available via email, phone, and our ticket support system.
- E-Mail: service@joy-it.net
- Ticket System: https://support.joy-it.net
- Phone: +49 (0)2845 9360 – 50
For more information, visit our website: www.joy-it.net
