Introduction

The Spectrum Analyzer in Nortek Deployment is a diagnostic tool used to identify electrical or acoustic interference affecting an instrument. It displays the frequency spectrum of the signals received by the instrument's transducers, making it possible to identify interference caused by external acoustic or electrical sources.

For an introduction to electrical noise and its impact on ADCP measurements, refer to the How to Identify and Reduce Electrical Noise Using Spectrum Analysis article.

Enabling the Spectrum Analyzer in Nortek Deployment

1. Connect to the instrument in Nortek Deployment.
2. Open Settings and enable Advanced Mode.
3. Navigate to the Diagnostics tab.
4. Enable Run Scripts. Alternatively, you can manually configure the instrument to stream spectrum data by saving the commands shown in the Spectrum Analyzer tab to a deploy file. Customize the commands as needed, then upload the file to the instrument. Once the deployment has started, you can view the data in the Spectrum Analyzer tab by clicking Start Spectrum Analyzer with Run Scripts disabled.
5. Select the desired Bandwidth and Number of Frequency Bins. The recommended bandwidth settings, corresponding to the default bandwidth used by each instrument during measurements, are listed in the table below. For the Number of Frequency Bins setting, it is recommended to use the highest number of bins supported by the communication method used to connect to the instrument. When connected over a serial connection, the number of frequency bins that can be displayed may be limited by the available serial data bandwidth. Therefore, we recommend connecting to the instrument via Ethernet when using the Spectrum Analyzer.

    6. Click Start Spectrum Analyzer.

Using the Spectrum Analyzer

Once the Spectrum Analyzer has started, an Amplitude vs. Frequency plot is displayed.

Several plot options are available from the menu in the upper-right corner of the window, allowing you to visualize the spectrum in different ways.

To interpret the results and identify electrical interference, refer to How to Identify and Reduce Electrical Noise Using Spectrum Analysis. This article explains how to recognize common noise signatures and provides recommendations for reducing electrical noise in your installation.