ETS HPM1-LL Instructions

HPM1-LL Microphone Instructions
The HPM1-LL ia a High performance, Omni-directional, pre-amplified piezo-electric hydrophone for acoustic
pickup in liquids up to 150' maximum depth. –10C to 85C operating temperature range. Can be hung by its cord
or mounted in a 7/8" hole
HPM1-LL Microphone Mounting
The HPM1-LL Can be hung by its cord or mounted in a 7/8" hole. The hydrophone comes with a sealing O-ring
and locknut. Do not mount the hydrophone on a surface that will pick up unwanted vibrations such as outboard
motors, ROV motors etc.
Cable Run
The HPM1-LL can be up t000 feet away from the receiving device, recorder, etc. Custom cable lengths of water
proof cable can be ordered for the Hydrophone. When ordering specify HPM1-LL-XXFT where XX = length of
cable in feet. You can also splice to the cable above the water line using any quality shielded #22 gauge 2
conductor shielded cable. See Figure 1 for connection diagram.
Wire Connections
Inside the cable are three conductors. The red wire is 12-24vdc, the black wire is the audio signal and the shield
is the common for both. These connections are directly compatible with ETS interface equipment. The figure
below shows the connections made to an ETS brand SMEA-1 IP camera interface.