Information about level and flow are important parameters for optimal operation of sewage and drainage systems. The resulting measurement requirements of the water and wastewater industry can be met by means of different measuring principles: for a large part of the level measurement applications, ultrasonic technology has proven advantages in application-specific cases and is considered a ‘standard’.
Compared to ultrasonic, radar provides the physical advantage that the emitted microwave pulses are unaffected by air movement and temperature layers existing across the test measuring section. This property can be advantageous in measurements under specific environmental conditions (e.g. strong winds, rain, fog, solar radiation) in terms of measurement accuracy.
Practical level measurement in water applications
According to Endress+Hauser, despite the physical advantage of the radar measurement technology, the question is raised whether in the daily operation of a water treatment plant it provides any increased benefit.
In practice, many typical applications such as wet wells, overflow basins and sewers are built underground or covered, so wind and sunlight have no effect on the measurement anyway. Also, ultrasound can score with higher accuracy at close range and gives equally flexible installation possibilities and low maintenance requirements. Furthermore, Endress+Hauser says experience shows that even with flow measurements in open channels and weirs, the typical measurement accuracy of ultrasound measurement (±2 mm and 0,17% of the measured distance) is sufficient. The accuracy of flow measurement can be influenced by precise design, construction, and especially by the installation in the channel.
In addition, for temperature dependent applications (e.g. in deep wells) an external temperature sensor can be used for measurement correction.
Expertise in the water industry
Endress+Hauser’s portfolio in the field of ultrasonic measurement is tailored to the needs of customers in the water and wastewater industry through state-of-the-art technology that provides an optimal price/performance ratio. In cases where ultrasonic has reached its limits, Endress+Hauser’s complete offering includes all the other principles of level measurement, such as freely radiating radar, hydrostatic or capacitive. The company has the expertise to advise the most suitable option.
Characteristic of Endress+Hauser’s ultrasonic level measuring technology include:
* Non-contact, maintenance-free measurement of polluted waters.
* Self-cleaning significantly reduces influences from condensation effects.
* Conductive grey sensor housing reduces heating by solar radiation.
* Separate instrumentation is the ideal solution for inaccessible measuring points.
* Temperature correction with integrated or external temperature sensor.
* Potted sensors give IP68 protection.
* Special functions such as rake and pump control.
* Suitable for use in hazardous areas.
For more information contact Jan Gerritsen, Endress+Hauser, +27 (0)11 262 8000, [email protected], www.za.endress.com
| Tel: | +27 11 262 8000 |
| Email: | [email protected] |
| www: | www.endress.com |
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