# Probe Head

Many of the Keysight's active, smart probes have SMB connectors on the front of the probe rather than regular probe leads. These probes are not complete without a probe head. The probe heads let you connect to many different types of circuits and signals using the same probe amplifier. Each probe head has unique features and limitations created for a specific use case. This also means that a probe head's electrical signal properties such as bandwidth, time delay, and attenuation are different as well. Accordingly, the oscilloscope software must know which head is attached in order to correctly sample and measure the signal.

Because probe heads cannot be detected by the oscilloscope, you can select the Probe Head block in the Probe Setup dialog box diagram and can choose the model number of the probe head being used.

Descriptions and pictures of the probe heads are shown to help with identification.

Some probe head models can be configured in multiple ways that will also affect the signal properties. For example, the N5445A has a variable width tip that can be adjusted to span different distances on a circuit. Changing the width of the tip has a noticeable effect on the frequency response of the probe, so the oscilloscope software must know the tip width as well. This is represented in the selection menu as a separate entry for each tip width. Other probe heads with multiple configurations are: E2678B, MX0100A, MX0106A, MX0109A, N2836A, N5425A/B, and N5439A.