Application range :
When it is difficult or even impossible to use LISN due to the large current consumption of the object under test , voltage probes are the first choice.
TK 9421/TK9422 is specially designed for measuring power supply electronics, such as switching power supplies with strong interference spectrum in the kHz frequency range.
For the functional inspection of the probe with a sine wave signal generator, please pay attention to the output voltage calibration reference under the usual 50Ω load. Connect a small carbon resistor of 50Ω in parallel to the probe; otherwise you will observe a high reading of almost 6dB (twice the voltage of the signal generator). The probe is not shielded to keep the input load capacitance to only 4pF. In the presence of a strong electric field, it may be necessary to slide a metal tube or copper foil on the probe body and ground it.
The voltage divider VT 9420 (TK 9420 option) can be used to determine the approximate RF impedance of the unknown EUT according to CISPR 16-2. Two measurements are required, one without a voltage divider and the other with a voltage divider. The difference between the two measurement results can calculate the impedance of the measured object. This calculation can only be approximate, and the uncertainty will increase above 10MHz.
specification model
|
TK 9420 |
TK 9421 |
TK 9422 |
input resistance |
1.5kΩ‖4pF |
1.5kΩ‖4pF |
5kΩ‖4pF |
Frequency Range |
9kHz-30MHz |
( 9 )150 kHz-30MHz |
( 9 )150 kHz-30MHz |
attenuation |
30dB |
30dB |
40dB |
Partial pressure accuracy |
30 kHz-30 MHz +/-0.5 dB |
150 kHz-30 MHz +/-1 dB |
150 kHz-30 MHz +/-1 dB |
Voltage range high frequency AC50/60Hz DC |
30V 2.5kV 4.4kV |
100V 10kV 15kV |
100V 10kV 15kV |
Maximum power |
- |
20 watts |
30 watts |
Receiver input impedance |
|