Instructions

Operator’s Manual

Adding Offset

The AP033 has true differential offset capability. This allows you to remove a DC bias

voltage from the differential input signal while maintaining DC coupling. By using probe

offset rather than offset at the oscilloscope inut, the full dynamic range of the probe

remains centered around the offset level. Add or remove offset using the oscilloscope

OFFSET controls.

Figure 6, Effect of Differential Offset

NOTE: In any software version later than legacy 8.1.0, the oscilloscope OFFSET

controls change the probe offset, rather than the offset at the oscilloscope input. The

OFFSET buttons on the probe body are disabled, although in Manual mode all other

buttons are functional.

In legacy software versions 8.0.0 and earlier, or when used with the ADPPS Power

Supply on instruments that lack ProBus support, probe offset must be controlled using

the OFFSET buttons on the probe body. The offset can be returned to zero by briefly

pressing the

↑

and

↓

OFFSET buttons at the same time.

AutoZero

The AP033 incorporates an AutoZero function to remove the DC offset from the output.

When power is first applied, the probe will return to the internal values resulting from the

last AutoZero cycle. After several minutes of warm up, or when the probe is exposed to a

large shift in ambient temperature, some DC offset drift may occur from thermal effects

in the amplifier circuitry. To adjust for this, manually invoke AutoZero.

CAUTION: Always remove the probe from the test circuit before initiating

AutoZero.