GRAPHTEC midi LOGGER GL220 - Measurement Readiness and Noise Mitigation

2-15
CHAPTER 2 Checks and Preparation
2.11 Precautions to Observe When Performing Measurement
Please be sure to read the following carefully in order to prevent electric shocks or shorts.
 • Donotapplyvoltageof60Vp-porabovebetweentheanaloginputsectionandmainunit,orbetween
analog input channels.
 • Donotapplyhigh-voltagehigh-frequencysignals(50kHzandabove).
 • BesuretouseonlytheACadapterprovidedasastandardaccessory.Theratedpowersupplyrange
for the adapter is 100 to 240 VAC, and the rated frequency is 50/60 Hz. Do not use any other voltages.
•Maximuminputvoltage
If a voltage exceeding the specified value is input, the semiconductor relay in the input section will be
damaged. Never input a voltage exceeding the specified value even for a moment.
<Between +/– terminals (A) >
•Maximuminputvoltage :60Vp-p
<Between input terminal/input terminal (B) >
•Maximuminputvoltage :60Vp-p
•Withstandvoltage :350Vp-pat1minute
<Between input terminal/GND (C) >
•Maximuminputvoltage :60Vp-p
•Withstandvoltage :350Vp-pat1minute
•InputCircuitDiagramforAnalogInput(Voltage,Thermocouples)
Capacitors have been incorporated into the input circuit to increase the noise elimination capability.
After voltage measurement, when the inputs have been disconnected, there will still be some electric
charge remaining. Before starting another measurement operation, short-circuit the + and - terminals to
enable self-discharge.
The GL220 has a scan system.
While in the status (open) in which signals are not input to the input terminal, measured results may be
influenced by signals from other channels.
In such a case, turn OFF the input setting or short circuit +/-.
If signals are input correctly, measured results are not influenced by other channels.
50Ω
50Ω
Channel Switching Relay
500kΩ
500kΩ
0.05µF
0.05µF