User Manual
GMC-I Messtechnik GmbH 49
8.9 Measuring Voltage – U (with SECUTEST PRO or feature I01 only)
U
Single measurements, rotary switch level: green
Switch
Position
Measure-
ment Type,
With Mains 
to Test 
Socket
Measure-
ment Type,
Without 
Mains 
to Test 
Socket
Measuring Functions
U
V – COM
U
  Measuring voltage, RMS
U
~ 
Alt. voltage component
U
= 
Direct voltage component
V - COM 
(with mains)
U  Measuring voltage, RMS
U
~ 
Alt. voltage component
U
= 
Direct voltage component
Mains to Test Socket
Schematic Diagram 
Wiring Diagram
Permanently Connected DUT
Schematic Diagram 
Wiring Diagram
Direct, alternating and pulsating voltages of up to 253 V can be 
measured between the V and COM socket terminals.
• Measurements with the voltage measur
ing input of the volt-
meter function (V–COM), electrically isolated from the mains
Setting Measuring Parameters 
Measuring 
Parameter
Meaning
Measurement Type,
Suitable for 
DUT Connection via
V – COM Display: RMS value + AC + DC Permanent connection
V – COM (with 
mains)
Display: RMS value + AC + DC; 
with mains to test socket, e.g. for 
measuring protective extra-low 
voltage at power packs
Test socket
Test Sequence, DUT at Test Socket (e.g. for measuring safety 
extra-low voltage at power packs or chargers)
➭ Set the rotary switch to the U position.
➭ Se
t the parameter to V – COM (with mains).
➭ Co
nnect the DUT’s mains plug to the test instrument’s test 
socket.
Attention!
!
Use only the included, contact-protected KS17-ONE 
measurement cables when measuring dangerous volt
-
age.
➭ Connect the DUT’s output sockets to the V and COM sockets, 
e.g. in order to be able to measure a safety extra-low voltage at 
the DUT’s output.
➭ S
tart the test: press the START/STOP key. 
➭ V
-COM (with mains): Acknowledge the warning which in-
dicates that line voltage will 
be connected to the test 
socket. 
 
➭ The measured values are displayed. The measured 
value recording symbol shown at the right appears. 
Each time th
is key is pressed, the currently displayed 
measured value is saved to the buffer.
➭ S
top the test: press the START/STOP key. 
The save symbol appears (floppy disk showing the 
number of measured values stored to buffer memory) 
and pr
ompts you to save the measured values to an ID 
number.
➭ P
ress the ESC key in order to discard the measured 
values stored to buffer memory and acknowledge by 
pressing the key shown at the right. 










