Emerson Process Management 5300 manual Automatic Surface Threshold, Interface Threshold

Rosemount 5300 Series

Reference Manual

00809-0100-4530, Rev BA July 2009

THRESHOLD SETTINGS Measurement with the Rosemount 5300 is based on the fact that the radar signal pulses are reflected by the product surface and the interface between two liquids. Various signal amplitude thresholds are used to separate the measurement signal from disturbing echoes and noise. Normally, the amplitude thresholds are automatically set by the 5300 transmitter, and no manual settings are needed. However, due to the properties of the product, it may in rare cases be necessary to adjust the amplitude thresholds for optimum measurement performance. RRM supports threshold settings in the Advanced Configuration window:

1.Click the Advanced icon in the Device Config/Setup toolbar.

2.Select the Thresholds tab in the Advanced Configuration window.

Figure C-6. Threshold settings in

RRM.

Automatic threshold settings are enabled by default. In the Advanced Configuration window the Interface, Reference, Probe End and Full Tank thresholds can also be set manually.

Automatic Surface Threshold

When this check-box is selected, the transmitter automatically sets the Surface threshold to a constant value based on the configured Dielectric Constant of the product.

Note that by enabling the Automatic Surface threshold setting, the Amplitude Threshold Curve (ATC) is replaced by a constant threshold value. See “Using the Echo Curve Analyzer” on page 7-10for more information on how to use the ATC.

The Surface threshold can also be manually set by using the Set Threshold function in the Echo Curve Analyzer/Configuration Mode window (see “The Configuration Mode Tab” on page 7-11).

Interface Threshold

Amplitude threshold for detection of the Interface level peak.

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