Instructions

Operator’s Manual

Matching Procedure for ÷10 Plugs

The ÷10 Plug-on attenuator provided as a standard accessory with the AP033 is calibrated

to match the specific probe it was shipped with. Individual probes will have small

variations in parasitic capacitance within the input circuits. To obtain maximum common

mode rejection performance, the attenuators are calibrated to match a specific probe

during the manufacturing process. In order to preserve the maximum Common Mode

Rejection, do not interchange external attenuators between probes.

The Plug-on AC coupling adapter is not matched to a specific probe and, therefore, does

not need to be matched. If the ÷10 Plug-on attenuators become accidentally mixed

between probes, you can use the procedure listed below to restore the compensation

match. This adjustment does not affect any of the parameters in the warranted

specifications. Therefore, the required test equipment does not need to be calibrated.

NOTE: The AP033 has different input capacitance. The 10 Plug-on attenuator supplied

with model AP033 cannot be properly adjusted for use with model AP033. Make sure that

the attenuator is marked “AP033” before attempting this procedure.

Equipment Required

Test Oscilloscope

The oscilloscope must support ProBus. For non-ProBus oscilloscopes, use the ADPPS

power supply.

Signal Source

Low frequency square wave: Frequency 50 Hz to 5 kHz, Amplitude 1 V to 10 V. The output

waveform must have a square corner and flat top with minimum overshoot suitable for

adjusting compensation. The generator should have trigger output, or use a BNC Tee

connector and separate BNC cable from the output to provide the trigger signal for the

test oscilloscope.

Interconnect Cable

This is for connecting the output of the signal source to the probe. A BNC cable and a pair

of small alligator clips or “lead grabber” adapter (Pomona #3788) may be used. 0.025 in.

(0.635 mm) Square Pins (3 required). The pins from the header supplied in the probe

accessory kit are suitable.

Tools

Flat bladed screwdriver, 0.040 in. (1 mm) wide

Adjustment Tool: 0.025 in. (0.635 mm) square head

NOTE: You can fabricate the Adjustment Tool by flattening the end of a 0.025 in. (0.635

mm) square pin with a file. Insert the pin into a short length of rigid plastic tubing to serve

as a handle.