43
────────────────────────────────────────────────────
4.4 Setting the Test Signal Level
────────────────────────────────────────────────────
4.4.4 Setting the Constant Voltage (CV) Level
Test signal level
setting screen
The digit keys (If held down continuously, the corresponding digit increments
or decrements continuously.) (If the limit for the corresponding digit is reached,
these keys change to non-reversed video and become inactive.)
Monitor display
Test frequency
Set value for
constant voltage
Voltage between test
samples
Limit value for the
current
Current flowing
through the test
sample
NOTE
1. Press this key to set constant voltage (CV), and the monitor display will
change immediately.
2. Change the set constant voltage value using the digit keys.
3. When the setting has been established, press the key to return to the
Initial screen.
Testing some types of sample is not possible using constant voltage. In this
case, the following symbol appears on the display:
In such a case, constant voltage testing is not performed. Change the
constant voltage level to a value not more than the value being shown as
Vmoni.
Reference
When a 1
μ
F capacitance is measured at 10 kHz, the CV operation range can be
obtained as follows. Sample impedance Zm becomes as follows:
Zm = Rm + jXm = 0Ω - j15.9Ω Xm=-1/(2πfC)
The impedance Zm' observed from the generator is as follows:
Zm'=Ro+Zm=50Ω - j15.9Ω Ro: Output resistance (50 Ω)
Accordingly, the voltage Vm across both leads of the sample is as follows:
Vm = |Zm|×Vo/|Zm'| Vo: generator output
= 15.9Ω×Vo/52.5Ω
Because the generator output voltage range is 10 mV to 5 V for 10 kHz, the
CV operation range per the above expression is Vm = 3.03 mV to 1.51 V
To Next Page
Loading...
