6 Checking the transducer by means of the Diagnostics functionality

The EK80 system can be set up to work with one or more transceivers. Each transceiver is assigned one or more transducers. By means of the Transducer page you can check the impedance of each transducer during normal operation. Any errors are then easily detected.

Prerequisites

The EK80 system is turned on and operates normally. Neither tools nor instruments are required.

Context

The transducer impedance is measured in real time during each transmission ("ping"). For LFM transmissions, the results are shown in two plots.

One plot shows the impedance as a function of the frequency in one ping. The other plot shows the phase as a function of the frequency in the same ping.

In each plot, one coloured curve is provided for each transducer or transducer sector. A single beam transducer is shown with only one curve. A split beam transducer is shown with several curves, one for each sector.

For CW transmissions, the impedance and phase values for each transducer sector are provided in a tabular format.

(The screen capture has been made while using a dummyload.)

Procedure

Open the Setup menu.

Select Diagnostics to open the dialog box.

Select Transducer to open the page.

Select which transducer to monitor.

Observe the impedance curve for the chosen transducer.

Select Fixed Axis to make the impedance curves easier to read.

An operational transducer element will have an impedance of approximately 75Ω ±40%. However, various transducers will have different values, and you need to check the relevant data sheet. Composite transducers have a relatively flat impedance curve. Older transducers with "ton-pilz" elements have a slightly higher impedance at the beginning of the ping. This is by design.

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If you measure ∞Ω (open circuit), you can assume that the transducer impedance transformer has broken, or that the cable is damaged.

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If you measure 0Ω (short), you can assume that either the transducer impedance transformer or the cable has shorted. You may also have a problem with salt water penetration.

Select OK to close the dialog box.