Benefits of using the SITRANS LR110 Radar Level Transmitter in Sewer Networks

The SITRANS LR110 is a new low cost FMCW radar level transmitter, packaged in a hermetically sealed PVDF enclosure for years of trouble-free reliable measurement service. It provides accurate level measurement to ranges of 15m. Remote programming is also convenient using the Bluetooth connection and SITRANS mobile IQ application on your smart device.

Due to its high level of reliability, accuracy and low power consumption SIEMENS have identified this instrument as the perfect partner for battery powered Remote Telemetry Unit’s (RTU’s) within the sewer network and for the SIWA Blockage Predictor application. As a result, extensive testing and development has taken place with both RTU providers and within the application itself

Reducing lifecycle costs by using intelligent sensors 

In an effort to drive down costs, it can be tempting to adopt very simple “cheap” sensors when implementing big data projects. Yet, these sensors often require more maintenance as well as delivering inferior performance. When selecting sensor technology, careful consideration should be given not just to the initial capex but to the whole lifecycle costs from an opex point of view. Many data hungry projects fail when moving to scale due to the increased maintenance burden placed on operational teams. Furthermore, this strategy can be at the expense of reliable, qualitative data, potentially paralyzing performance improvement efforts through poor or lost data.  Process measurement and data quality are the foundation stones for data science and therefore correct sensor and RTU selection is critical to maximise value from big data projects.

A recent analysis of the reasons for false alarms drew some interesting findings. It was stated that 80% of all alarms were false positives. Poor install, equipment failures, contractors not notifying monitoring teams as well as incorrect interpretation of data, were all cited as reasons for false positives. However, installation and sensor fouling issues were the most common causes for false alarms.

Due to the large number of false alarms, it was determined that a cost analysis would help highlight how much this was costing the business. Call-out costs can be quite variable and dependant on the distance travelled, number of men required and the need for Traffic Management (TM).

Below is an estimated price based on the following assumptions in order to try and understand the cost of these false alarms due to poor sensor installation and performance.

o  4 callouts a week

o  Three-man team with resolution being found within a couple of hours

o  Cost approximately £40 per hour per man

o  Traffic Management approximately £800 a visit plus an engineer to provide TM plans prior to the visit

o  Some TM will only be authorised out of hours and as such will double the labour costs.

Total Costs Potentially Over £200,000/yr

Whilst improving the sensor and data reliability may not eliminate all these costs it would certainly drive them down, free up engineering time and allow better job prioritisation.  The small additional cost for a more reliable, intelligent sensor now seems less significant when compared with the ongoing additional maintenance costs over the sensor’s lifecycle.

Consequences of poor data quality 

By conducting “persona interviews” SIEMENS take a holistic approach that considers all the project stakeholder’s requirements. This offers the end-user inclusive remedies that breakdown a “silo mindset” and offer a more complete proposal. Some of the most common operational comments from our persona interviews were around poor sensor installation or selection leading to missing or poor-quality data.

 The five major consequences of poor-quality spill data are:

1. Poor decision-making -  Difficulty in the prioritisation and handling of the workload
2. Business inefficiencies - Missing data can extend spill duration, affect operational uptime and increased maintenance costs due to replacements or removing rag
3. Mistrust - Lack of confidence in sensor data as well as lowering customer confidence
4. Missed opportunities - Root cause analysis of problems are missed due to lack of time and therefore persistent repeat offenders continue to cost time and money
5. Lost revenue - Increased opex costs and potential Ofwat penalty payments / fines from the regulator

Many of these operational issues can be avoided by correct sensor selection and improved data quality.

Operational advantages of the SITRANS LR110 Level Radar Sensor

The SIEMENS solution uses ultra-reliable, low-cost radar sensors that are unaffected by many process issues as well as having some immunity to sensor ragging. In using the HART communication protocol, we can read not just the level but return valuable diagnostic information such as measurement confidence and sensor temperature, all from the one device. This data rich sensor enables us to have greater confidence in the sensor health and process measurement.  When used with the Siemens SIWA Blockage Predictor (SBP) app, it also offers a more complete, end-to-end solution, fully tested by SIEMENS that includes these other advantages:-

End-to-end solution guarantee

Pretested components with a guarantee of performance and single source accountability for the entire end-to-end solution

Simplify onboarding to reduce risk and engineering cost

The SITRANS LR110 radar level sensor offers easy parameterisation and onboarding using Mobile IQ app with no additional engineering / development required.

SIEMENS sensors are pre-tested with the RTU and have pre-set RAG thresholds for sensor health within SBP/EDM app.

Less maintenance /opex costs

The SITRANS LR110 radar level sensor has “auto false echo suppression” feature to ignore obstructions and eliminate false level readings.

Radar sensors are unaffected by vapours, foam and high levels of condensation.

Data reliability even under flooded / submerged conditions.

Remote Bluetooth communication reduces need for entering manholes / confined spaces.

Improved data confidence

The SITRANS LR110 level transmitter has HART comms for reading the sensor health status as well as process variable with pre-set RAG thresholds for sensor health visible in SBP.

The diagnostic data is available direct from the sensor without the need to visit site, while cross referencing process values, echo confidence in SBP reduces false positives

Correlation across the estate: Verify status of float level switches

Using the measurement confidence value as well the primary variable enables validation of existing EDM float level switch readings in the network

Multipurpose sensor for both EDM and SBP requirements

Buy one sensor, with just one source of data, that meets all requirements for both EDM & SBP. This enables sensor rationalisation for both applications in both Safe Area and ATEX locations. 

EDM compliant and sensor reliability

The SITRANS LR110 has a 2mm accuracy which complies with the "CIWEM EDM Good Practice Guide", this document recommends tolerances over the weir structure should be within ± 5mm.

The SITRANS LR110 Level sensor will work under flooded/submerged conditions with zero blanking distance for low headroom installations and is unaffected by vapours, foam and high levels of condensation. The sensor also has very low power consumption to extend the RTU battery life.

MCERTS compliant sensor for possible volumetric flow and future regulation

With the ability to measure volumetric flow in conjunction with a Primary Flow Devices (PMD) the sensor ensures a futureproofed design in readiness for improved regulation.

Summary

The SITRANS LR110 is our sensor of choice for applications in the sewer network because business information is only as good as the data that’s behind it. While most people appreciate the value of data quality, it can often be pushed aside in the desire to reduce initial capex costs, forgetting all that comes after, depends on reliable data quality.  Simple low-cost sensors may reduce capex costs in the short term, but when considering “whole life cycle costs”, better value comes from sensors that are data rich, offer ease of integration, greater reliability and reduced maintenance costs. Good quality data is a crucial commodity when assessing asset performance and delivering cloud-based services efficiently. That’s why SIEMENS recommends the SITRANS LR110, as the most dependable level sensor, capable of delivering reliable, qualitative data, with low power requirements throughout the sewer network. When used alongside SIWA Blockage Predictor, it allows end-users to properly realise benefits from enhanced forecasting, better business decisions and improved operational efficiencies. It is therefore, often a false economy to buy “cheap” sensors, at the risk of jeopardising improvements to PR19 performance commitments, that may well result in increased penalty payments, lost revenue, not to mention operational inefficiencies.