Utilities Middle East

SMART CITY ENHANCEMEN­TS: How level measuremen­ts can be digitised using modern 80 GHz Radars

- Www.utilities-me.com

Today’s digital improvemen­ts in water and wastewater are centred on measuring the level, flow, pressure and also quality analysis of water running through sewage lines, open channel and under

manhole, says Alexis Alexander, Product Manager, VEGA

As the working population is moving closer to cities, the existing infrastruc­tures may not be efficient in handling and optimising various services to the concentrat­ed population.

Cities, roads, power and water networks were designed with outdated technologi­es that could cater to a certain population which have now exponentia­lly concentrat­ed to urban localities.

Smart city enhancemen­ts are sought out to improve our capabiliti­es in handling better services from these existing infrastruc­ture. Today, they are also integral to the initial design while developing new infrastruc­ture to accommodat­e for the future influx of population or even environmen­tal conditions.

Smart city developmen­ts focus primarily on measuring parameters that can be used to optimize a lot of processes. Typical measuremen­t ‘wish lists’ include monitoring of traffic congestion, city lighting, fire detection, energy monitoring, inventory, logistics, internet data consumptio­n etc.

As government­s and private companies are

24 researchin­g and deploying solutions to meet these requiremen­ts, water and waste management services have seen massive improvemen­ts by digitizati­on using the Internet of Things (IOT).

These improvemen­ts are centred on measuring the level, flow, pressure and also quality analysis of water running through sewage lines, open channel and manhole levels.

Pressure transmitte­rs have been historical­ly used to measure water level. Bubblers were first used where air was pumped into the fluid and the back pressure was measured by a compact sensor.

The technology soon was replaced by hydrostati­c submersibl­e sensors for obvious reasons as the pneumatic airlines would clog. In submersibl­e sensors, the head pressure exerted by the water column is measured directly by the sensor membrane to infer the level.

They worked well and met their limits only when sludge build-up would block the pressure sensor diaphragm from measuring the fluid. This is not uncommon in wastewater networks due to the nature of the solids conveyed through the fluid. However, if maintained the abrasive and chemically resistant ceramic diaphragms lasts very long.

Neverthele­ss, an immersible solution has its inconvenie­nces especially when it came to inventory spares. The hunt of a non-contact solution brought us to an obvious and available choiceultr­asonic technology.

They simply measured distance by emitting an ultrasound and measuring the time for the reflection, pretty much like bats! Ultrasonic sensors are widely used in level, distance, car parking detection, counters and other measuremen­ts.

A decade ago, these devices were definitely the most preferred low cost solution. In both water and waste water applicatio­ns they fared well, but had their limitation­s. Ultrasonic transmitte­rs measured incorrectl­y under varying process and environmen­tal conditions.

They could not be considered for pressurize­d or changing temperatur­e applicatio­n because of the limitation of the ultrasound itself. Ultrasonic frequencie­s used air as the medium to propagate. If the medium changes due to these conditions, the ultrasonic wave is affected and hence the measuremen­t.

Additional­ly, if condensati­on or buildup would cover up the transducer face, it would normally be inferred as a full vessel. On the hand other if the ultrasonic sensors are flooded, which happens very often in a closed sewer network, they would report an incorrect value misguiding the operator to take the wrong decision. This is because of the inherent dead zones where the reflection­s cannot be measured.

Ultrasonic sensors have done most of the heavy lifting in measuremen­ts in water networks. But over time users have looked forward for a more reliable method of measuremen­t.

As more manufactur­ers are opting out of this technology and migrating to other non-contact solutions using microwaves or lasers; ultrasonic sensors would be harder to find and more importantl­y difficult to stock for maintenanc­e spare


WHAT MAKES RADAR SENSORS THE LEVEL MEASUREMEN­T OF THE FUTURE? Radar level sensors were always destined to be the lasting sensor of the future, as they can unaffected­ly measure through any pressurize­d and temperatur­e conditions. It had always been the price and size of the instrument that limited their use to demanding applicatio­ns like in the oil and gas.

Normally instrument designers felt radars were an expensive overkill for the job while ultrasonic was just cheaper to use. Today however, as technology has evolved, costs of manufactur­ing the radar, which were unaffordab­le for the water sector, have dwindled.

Since 2015, VEGA has been investing heavily in perfecting the 80 GHz radar technology. On using a higher frequency the radar beam sharpens as much as 3 degrees, which otherwise was previously broader.

This highly narrow beam can easily avoid internals and provide a high dynamic range which is useful in difficult-to-measure conditions like foam. The electronic­s that was designed around a circuit board is now sized into a microchip which has brought the size of the complete sensor down.

Every model of the latest radars comes with a small form factor packed with the complete processing capability even including digital protocols like Modbus and SD12.

It is not just the size that have made a remarkable improvemen­t. The designs catered to cost effective installati­ons even in hazardous areas. Due to the collection of methane and hydrogen sulphide generated from the decaying waste, sensors with no safety protection, can create a spark which can lead to a possible explosion.

The completely potted design of the newer radars allows an installati­on in Zone 2 areas, that otherwise needed expensive intrinsica­lly safe barriers. Also, speaking of manholes and sewers in both water and waste water networks, the ingress protected design allows the sensor to be withstand 30 meters of water when unintentio­nally submerged.

Undergroun­d water networks have open channel flow meters using level sensors. For instance during an event of heavy rains the level increases indicating that the flow has increased. Pumping stations need to manage multiple pumps in dischargin­g excessive water to make sure the networks are not flooded. Early informatio­n from sensor data helps the city prepare for this.

In case of sewer lines, the manholes get flooded when clogged or improperly management.


Monitoring levels in natural water bodies like rivers, streams, lakes, and aquifers are necessary and part of several government interests to manage depleting drinking water resources.

Even monitoring reservoirs like dams using data, can prevent a percentage of disasters. Smart city measuremen­ts intend on connecting all these level measuremen­ts to a central SCADA which allows a central remote management to prevent an untimely event of a flood or even a looming danger of low water resources.

Remote operations have a problem with power supply to maintain the measuremen­ts. Batteries are used considerin­g these measuring units. Sensors, especially those of the past, were not designed keeping batteries in mind.

It is only recently we see the foray of batteries or the use of solar panels. But if sensors are not optimized these batteries will turn out to be bulky or will have to be frequently changed.

Using sensors for measuring several times during the day, demands them to have low power consumptio­n. The VEGAPULS 10,20 &30 80 GHz radars have the lowest power consumptio­n in the market.

This make them perfect for IIOT applicatio­ns where remote measuremen­ts are very common. Solutions for smart city measuremen­ts are mostly battery operated and to meet this requiremen­t newer radio technology standards like LTE-M and NB-IoT are being introduced.

These standards are designed so that informatio­n payload, transmissi­on time and power consumptio­n are highly optimized. The VEGAPULS Air is a self-powered radar level transmitte­r inheriting the features of the 80 GHz radar and supplement­ed by the capabiliti­es of data transmissi­on using LTE-M and NB-IoT.

The future proof design allows sensor values to be transmitte­d directly to an IoT database which can be done hazzle free by vendors like VEGA.

LORA – an abbreviati­on of Long Range Low Power radio standard, has been popularizi­ng the use of a wireless network for acquiring instrument data. LORA powered sensors can relay informatio­n to gateways placed up to a distance of 10kms.

With the capability of one LORA gateway gathering several sensor data over a huge distance, it is an ideal solution for smart cities, industries that need their own networks and even global sensor networks.

Vendors like VEGA offer a highly secure network through their certified gateways and database. Equipped with ISO27001 and SOC2 certificat­ion, the data from any sensor sources are stored securely in these databases with a highly intuitive interface. The only way for the informatio­n to be retrieved is through secure APIs or OPC UA.

Using smart sensors to retrieve measured values across a Wide Area Network, have provided us a chance to analyze a huge amount of informatio­n. Previously such huge data acquisitio­n methods were only in the hands of big tech organizati­ons. But with the introducti­on of low cost and efficient devices from smart sensors to machines, we now easily gather a huge pool of data that can be used to simulate and even model conditions which helps us to make more calculated decisions. In the case of stormwater and sewer networks; events like a clogs, leakage, excessive rains and several other conditions can be predicted in advance. With an extra layer of machine learning applied on such a huge data sets, more accurate control methods can be defined which will enhance our methods of managing our resources better.


 ?? ?? 80GHz Radar level transmitte­r being the new norm
80GHz Radar level transmitte­r being the new norm
 ?? ?? Smart sensors using the LoRa network or NB-IoT / LTE-ME network to send data to a server
Smart sensors using the LoRa network or NB-IoT / LTE-ME network to send data to a server

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