Connecting the probe
R&S
®
RT-ZC20B
18
User Manual 1802.9967.02 ─ 01
3.6
Considerations for measurements
Measurements of continuous input current
To avoid damage to the probe when doing measurements of continuous input cur-
rent, consider the following:
●
The maximum continuous input range is based on heat that is internally gen-
erated during measurement. It varies according to the frequency of the current
being measured. Refer to the data sheet "R&S RT-Zxx high voltage and cur-
rent probes".
●
The device may sustain damage from self-heating even at current levels that
are lower than the maximum rated current. The maximum rated current is a
recommended value that assumes sine-wave input under standard conditions.
Self-heating may happen if the ambient temperature increases or the mea-
surement current waveform contains other frequency components.
●
If the input current exceeds a certain level, generated heat activates a built-in
safety function that blocks normal output. If this happens, remove the input
immediately (remove the sensor from the conductor being measured, or
reduce the input current to zero). Wait until the sensor has had sufficient time
to cool before resuming operation.
Continuous input of current exceeding the rated maximum or repeated activa-
tion of the safety function may result in damage to the device.
●
Even if the input current does not exceed the rated continuous maximum cur-
rent, continuous input for an extended period of time may result in activation
of the safety circuit to prevent damage resulting from heating of the sensor.
At high ambient temperatures, the built-in safety circuit may activate at current
input levels below the rated continuous maximum current.
●
Current measurement exceeding approx. 1 kHz may result in temperature rise
on the sensor-head. This is attributed to excitation loss that cannot be preven-
ted due to natural physical principles. Be careful to avoid injury, electric shock
due to short-circuits, or damage to the device that may be caused by the
increased temperature.
●
Do not place any unclamped conductor with an electric current of a frequency
of 10
kHz or more near the sensor head. Current flowing in the conductor
nearby may heat up the sensor head and cause its temperature to rise, lead-
ing to damage to the sensor. For example, when one side of a go-and-return
conductor is clamped and the other side is also placed near the sensor head
as shown in the diagram, even if the electric current is lower than the consec-
Considerations for measurements