Joy-it JT-UM25C User manual

JT-UM25C
USB-Messgerät
1. GENERAL INFORMATION
Dear customer,
Thank you for purchasing our product. In the following are information
which you should note before commissioning. Whenever you have
unforeseeable problems do not hesitate to contact us.
Today, USB connections are not only found at PCs, but also at power
banks, in cars or in trains. But not all connections are of best quality and
deliver even currents and voltages.
With the JT-UM25C, you always have all values in view. The meter 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 oers 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 regulated in ve brightness levels and provides always
an overview of all measured values.

2. DEVICE OVERVIEW
Voltage measuring range
Current measuring range
Update rate
Measurement accuracy
Temperature range
Display size
Supported
QuickCharge
modes
4 - 24 V
0 - 5 A
2 Hz
0,001 V / 0,0001 A
-10 - 100 °C
1,44“
QC2.0, QC3.0,
Apple 2.4 A / 2.1 A / 1 A / 0.5 A,
Android DCP, Samsung
USB-A Port
(female)
BT switch
4x multifunctional buttons
microUSB-Port
USB-C-Output
(only VBUS, GND, CC1,
CC2)
1,44“
Color Display
BT status (changes by
a connection from
ashing light to a
permanent light)
USB-C-Input
(only VBUS,
GND, CC1, CC2)
USB-A Port
(male)

3. FUNCTION MENU AND NAVIGATION
General use
Measurement result
main page
QuickCharge
detection
Recording of charging
process
Cable impedance Measurement graph System settings
Use and to switch between the separate
menu pages.
Hold to switch to the next data group. Hold
to reset the current data group.

Main menu (measurement results)
Hold to rotate the
display
counterclockwise
Press to turn o
the display
Press to rotate the display
clockwise
Hold to open the
help menu
Press for the
previous page
Press for the next
page
Voltage
Current
Accumulated
electrical loading
Accumulated
energy
Temperature
Data group
Equivalent resistance
Power consumption
The values of the data group 1 - 9 will be saved by a voltage interruption
of the measuring device and is recalled and continues aer the device is
switched on again.
The values of data group 0, however, will be showed aer the restart
ashing and then it will be reset to 0 when 1mAh has been reached.

QuickCharge detection
The meter automatically recognizes devices with QuickCharge support.
The following QuickCharge modes are currently supported:
QC2.0. QC3.0, Apple 2.4 A / 2.1 A / 1 A / 0.5 A, Android DCP, Samsung
Recording of charging process
Voltage of
D+ (DP)
Voltage of
D- (DM)
Mode indicator
Accumulated
electrical loading
Accumulated
energy
Total
accumulation
time
Trigger current
for recording
Recording indicator
Red: Recording paused
Green: Recording in process
Aer power is turned on, if the owing current is greater than the trigger
value, the system automatically starts recording the
accumulated electrical charge, energy and elapsed time. The „REC“ indica-
tor then changes from red to green.
To set the current trigger value, press and hold it to
highlight the value. Press to adjust the value accordingly.
The value can be set anywhere between 0.01 A and 0.3 A.

Cable impedance
Measurement procedure:
First, connect the measuring device directly to the source and set the
corresponding current load (recommended value: 1 A). Press
and hold the button to start data recording.
Now, disconnect the meter and then connect it to the power source via a
microUSB or type-C data input connection and set the load current to the
same value as in the rst step. Press and hold the button to
switch to the to begin data recording.
The display prompt stops ashing and the resistance measurement test of
the data connection cable is completed and the value is displayed.
UM25C directly at the power
supply system:
Voltage and current values
are displayed
UM25C via data connection:
Voltage and current values are
displayed
Resistance of the data
connection cable
Attention! If the screen goes black in the second step, this means
that the voltage dierence is too high and the tester switches to the
4 V shutdown state. The load current must be reduced.
Then restart the measurement from the rst step. Aer the
resistance test of the data connection cable is completed, the tester
must be switched o and on again to continue the measurement.
Measurement graph

This menu displays the voltage measurement over time in the range of
4 - 24 V, as well as the current measurement in the range of 0 - 5 A and
automatically adjusts the displayed range in real time to account the
voltage and current uctuations.
Press and hold to switch D+ / D- graph. This interface
displays the D+ / D- voltage measurement over time in the range of
0 - 3.3 V and automatically adjusts the displayed range in real time to
account the D+ / D- voltage uctuations.
System settings
Time until automatic
screen shutdown
(default 1 minute) Screen brightness
(default level 4)
Display temperature
(default Celsius) Background color
scheme (default 2, blue)
Foreground color
scheme ( default 6, white)
Press and hold the button to enter the setting mode,
press again to navigate through the options. Then press
to change a setting and press again to
cycle through the setting options. At each setting state, press and hold
to exit the system settings.
4. PC - SOFTWARE
1. Connection
First download the soware installation le here.
Additionally, you need the font package Arial Unicode MS.ttf,
which you can download here. Please install the font package rst, before
you continue with the installation of the soware.
Now, install the soware and follow the instructions there during the
installation process.
Aer the installation process is completed, activate
rst of all the BT function on the UM25C measuring device with the
BT switch.
Then use the BT search in the settings of your computer to search for new
BT devices. Add the UM25C device when it is found. If you are asked for a
PIN during connection setup, please use the pin 1234 or 0000.

In order to be able to connect the installed soware to the measuring
instrument, it is necessary to know which port is used, to connect the
instrument to your computer. To do this, select in the
BT connection overview BT settings.
In the window that now opens, select the COM ports tab. The necessary
interface in this case is UM25C‘Port‘.
The screenshots shown here are from Windows, trademarks like Bluetooth or
Windows belong to their respective owners.

2. Usage of the soware
Now, open the UM25C PC soware V1.3, which you have already installed
on your computer. First, set the appropriate COM port to which the
measuring device is connected to your computer and start the connection
with the Connect button.

1
2
3
4
5
6
7
8
Basic functions
(previous page, next page, rotate screen)
Data groups
(direct selection of the data groups)
Main measuring interface
Data recording interface
QuickCharge interface
Temperature overview
Screen brightness,
Time for automatical image shut down
Voltage-current diagram
With a right click within the voltage-current diagram, further options are
available. Here, you can automatically scale the x-axis, copy the current
data to the clipboard or rather export it as an Excel le, export the current
graph as an image or delete the current graph.