The Hand Probe Microphone - Gutermann AQUASCOPE 550 Operating Manual

4. The Hand probe Microphone

Screw the desired amount of probe rods together as required, generally
an extension together with the Tip rod is recommended. Next, attach the
rod assembly to the hand probe Microphone. The longer the rod
assembly the more background noise is introduced especially on windy
days. It is also possible to lag the rod with pipe insulation to reduce wind.
Use the Binder plug to connect the hand probe to the lower socket on the
AQUASCOPE 550, see fig 7.noise.
The hand probe is used for direct sounding on pipes and fittings. For
direct sounding we recommend to use the "filter off" mode described in
chapter 10.