
1-11
IM DL350-03EN
1
2
3
4
5
6
App
Index
Names and Functions of Parts
1.5 Structure of the Instrument
Module Isolation
The signal input section of each channel of this instrument is isolated within the modules.
*
This enables
isolated measurement between channels.
* There are some exceptions. For details, see the specifications of each module in chapter 6.
Instrument Ground
The following terminals on this instrument are at the same electric potential as the functional ground
terminal and are not isolated.
• GND terminal of the external I/O terminal
• GND terminal of the logic input terminal
• GND terminal of the probe compensation signal
• GND of the USB terminal
• Ethernet connector shell
• GND of the GPS signal input terminal
When the AC Adapter Is in Use
The dedicated AC adapter of this instrument is functionally grounded. As such, when the AC adapter
is in use, the GND of this instrument is functionally grounded, which increases the tolerance against
noise.
When the AC Adapter Is Not in Use
If you do not connect the AC adapter and run the instrument on a battery, the GND of this instrument
will not be functionally grounded. If you use this instrument in a noisy environment, measurement
results may be affected by the noise, or interface communication may not operate properly. These
problems may be alleviated by connecting the functional ground terminal to ground.
If the instrument is not functionally grounded and you measure a high voltage signal at high
frequencies, such as that of an inverter, you may feel the contact current.
CH1
CH2
Module
Slot 1
CH3
CH4
Module
Slot 2
Main body
• GND terminal of the
external I/O terminal
• GND terminal of the
logic input terminal
• GND terminal of the probe
compensation signal
• GND of the USB terminal
• Ethernet connector shell
• GND of the GPS signal
input terminal
Electrical isolation
GND is common.
When the AC adapter
is in use
Functional ground terminal
DC input
DL350