Nivetec Echo Smart Series, Руководство по эксплуатации и установке, Страница: 34 / 73

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6.2.
Sensor Location Selection Criteria
Optimal performance depends on: (1) acceptable process liquid (supernatant) in which
the ultrasonic pulse is to be transmitted, (2) responsive interface material (suspended
solids blanket, other settled solids), (3) freedom from objects encroaching into the path
of the transmit pulse, and (4) avoiding areas of excessive turbulence.
6.2.1. Acceptable Process Liquid
Most relatively uniform and homogeneous liquids found in water and wastewater
treatment applications and many industrial process applications are suitable for
transmitting the ultrasonic pulse. Excessive amounts of suspended solids, gas or air
bubbles or other concentrations of solids in the supernatant may inhibit or obstruct
the signal. The sensor should be positioned to avoid these conditions if possible.
6.2.2.
Responsive Interface Material
The EchoSmart Sensor relies on minimal qualifying characteristics of the material
that is it measuring. Relatively dense, well-settled suspended solids form a well-
defined interface and are effective in reflecting signal to the sensor. Light density
material (< 0.5% solids) that is not well-settled does not form a well-defined
interface and is less effective in reflecting signal to the sensor. If possible, locate
the sensor in an area that minimizes exposure to these conditions. Attempt to
position the sensor in an area where the material (sludge) is relatively deep in the
tank under normal process operating conditions.
6.2.3. Stationary Objects in Path of Transmit Pulse
Do not locate the sensor near piping, tank structural elements, or other objects that
encroach on the signal trajectory. Continuously moving rakes and skimmers found
in water and wastewater treatment applications typically do not interfere with
measurements.
6.2.4.
Areas of Excessive Air/Gas Bubbles and Turbulence
Avoid locating the sensor in areas where there are high concentrations of air/gas
bubbles or suspended solids in the supernatant. When possible, select sensor
locations to avoid these conditions
.