A new module for the Liquiline platform makes it easy to combine data from up to six digital Memosens sensors in hazardous areas into a single transmitter in a safe area. Reducing the number of transmitters needed saves space and installation costs and opens up digitalisation opportunities from the sensor to the PLC.
As the CM44 transmitter is located outside of the hazardous area, it’s easy to access for maintenance. And the stable Memosens connection offers precise and sensitive measurement even in traditionally difficult applications.
The upgraded transmitter is a space-saving solution for multiple industries with hazardous area protocols such as chemical, oil & gas and water & wastewater. Applications include inlets at wastewater treatment plans, chromatographic and filtration processes in life sciences, production of spirits in the food & beverage industry and water treatment on offshore platforms or vessels.
Whatever the parameter being measured – pH value, conductivity, oxygen and so on – Memosens offers unrivalled accuracy. Unaffected by moisture or corrosion, Memosens ensures reliable data transmission wherever it’s needed. All the sensor data can be fed to the PLC via a single transmitter using either 4–20mA HART or a digital fieldbus communication protocol.
We asked Oliver Durm, Senior Product Manager for Endress+Hauser Liquid Analysis, to explain more about how the idea came to fruition.
What was the thought process behind the development of the new module?
It was really in response to customer requirements. The Liquiline is non-Ex, so it always has to be placed in a safe area. But inlets at wastewater treatment plants, for example, are often classed as hazardous areas. However, just a few metres away from the inlet channel there is a safe area, and so this is the perfect use case for the CM44 transmitter with the Ex-i module. Another good example is in life sciences: here you often have processes with explosive atmospheres, so the sensors need to be considered Ex but the transmitter can be housed separately outside the explosive area. The advantage with the CM44 transmitter is the multi channels, so you can connect pH, oxygen and conductivity sensors, for example, at the same time with one small device. Typically, solutions for hazardous areas are one-channel transmitters, so you have a separate transmitter for each device, which needs space. Now we also have a DIN rail device that can be installed inside a small cabinet and connects several sensors.
Are there any other applications?
In the marine business and especially on oil & gas tankers, you always have hazardous areas, and ships now have to treat their ballast water. That’s because there’s legislation in place to prevent the spread of harmful aquatic organisms from region to region. The ballast water has to be disinfected and carefully monitored before it can be discharged into the sea. For this application the transmitter is normally installed in the engine room or in the bridge, in the safe area, while the sensors can go in the Ex area. So there are applications in lots of different areas: life sciences, marine, water & wastewater and also food & beverage, for example in distillery applications. That was the reason why we developed this module.
Other Liquiline transmitters already have Ex capability. Why was it important to develop this module for the CM44 in particular?
It’s well known, particularly for its communication technology. The CM44 can be used with Ethernet communication, PROFINET, EtherNet/IP, Modbus RTU and Modbus TCP. With all these digital protocols, we are the only ones on the market to offer a multichannel, multiparameter device with ‘connectivity’ in a design that’s optimized for small spaces. And there are some applications, for example in wastewater, that only the CM44 can handle. So it was obvious for us to develop something to fulfil this customer requirement for hazardous areas that can connect multiple sensors.
Memosens sensors have used digital communication since their inception back in 2004, and now it seems the whole world is going digital! Is Memosens as relevant as ever?
Absolutely! Everyone wants to reduce carbon emissions and become more sustainable, and this is only possible with digitalisation. This is because when we talk about reducing carbon footprints, we mean reducing the energy required to run your plant. You need good process control to balance the highest possible yield with the lowest energy input. In a wastewater plant, for example, you control the biological steps such as aeration, which is a huge energy consumer, to find the perfect balance of oxygen injected into the water and energy use.
On the other hand, when we talk about digitalisation, you also have to think about maintenance, because a lot of plants are unmanned and controlled remotely. With an analogue system you would have to drive to a plant every few days to ensure that everything is running OK. Now, with digital, a lot of those journeys are unnecessary. Digital sensors also allow you to go beyond the pure measurement value to get additional information – to plan your maintenance, for example. And if you do have to drive to the plant you already know exactly what needs fixing and which spare parts to take with you, meaning you don’t have to go back a second time. So digitalisation helps in lots of different ways to reduce carbon production and improve sustainability.
Are customers on board with the digital journey?
It’s certainly getting more momentum and solutions like this help to engage people. We had a customer in life sciences who wanted to have complete documentation when something was changed in the field. With digital communication technology this information is all tracked in your PLC or SCADA system. So even if a sensor exchange happens at the weekend when most people are away, it’s automatically recorded with serial numbers, times, dates. So they get complete 100% traceability, and this is something which is helpful to show the authorities that you have complete documentation and data integrity. In life sciences and in other industries like food & beverage this is getting more and more important.
For more information on Endress+Hauser’s comprehensive range of liquid analysis products visit www.uk.endress.com/en/field-instruments-overview/liquid-analysis-product-overview