Tektronix TDS 640A Sprinkler User Manual


 
Probe Selection
TDS 620A, 640A & 644A User Manual
3Ć105
amplifiers) to precisely connect your instrument to your deviceĆunderĆtest.
These probes have the same electrical characteristics as high speed, active
probes but use a smaller mechanical design.
Current probes enable you to directly observe and measure current waveĆ
forms, which can be very different from voltage signals. Tektronix current
probes are unique in that they can measure from DC to 1 GHz.
Two types of current probes are available: one that measures AC current
only and AC/DC probes that utilize the Hall effect to accurately measure the
AC and DC components of a signal. ACĆonly current probes use a transĆ
former to convert AC current flux into a voltage signal to the oscilloscope
and have a frequency response from a few hundred Hertz up to 1 GHz.
AC/DC current probes include Hall effect semiconductor devices and proĆ
vide frequency response from DC to 50 MHz.
Use a current probe by clipping its jaws around the wire carrying the current
that you want to measure. (Unlike an ammeter which you must connect in
series with the circuit.) Because current probes are nonĆinvasive, with loadĆ
ing typically in the milliohm to low W range, they are especially useful where
low loading of the circuit is important. Current probes can also make differĆ
ential measurements by measuring the results of two opposing currents in
two conductors in the jaws of the probe.
Figure 3Ć55:ăA6303 Current Probe Used in the AM 503S Opt. 03
Current Probes