The Liquiphant revolutionized level measurement. The latest generation of the point level switch sets, according to product managers Martin Pfändler and Artur Jede, new benchmarks in the digital era. Let’s see what they have to say about the success story of the Liquiphant.
Mr Pfändler, you codeveloped the Liquiphant in the early 80s. Did you ever believe it would become an industry classic?
Pfändler: Not really. We conservatively estimated we would sell 500 in the first year, but then demand for the instrument exploded right after the trade fair introduction. We ended up producing 5,000 units. Today, it’s more than 300,000 a year.
What was the development phase like? Georg H Endress had a clear vision…
Pfändler: The company founder wanted a 100 percent metal, permanently waterproof sensor with a rod that could detect if a liquid was present in a tank. When we realized that the single-rod solution couldn’t deliver the required physical performance, we pursued a double-rod approach in the form of a tuning fork. This led us to create and patent the vibronic measurement principle, which uses piezoelectricity to oscillate the fork. When submerged in liquid, the frequency changes and this change is converted into a switching signal.
To what do you attribute the success?
Pfändler: Before Liquiphant was introduced, users lacked a way to safely and reliably detect liquid levels. Back then the industry primarily used float switches, which are extremely susceptible to incrustation caused by the build-up of deposits. The maintenance effort was accordingly extensive.
Jede: Unlike conductive and capacitive sensors, with Liquiphant the measurement results are not influenced by the physical properties of the media. Even foam and build-up do not interfere with the measurements. That means it can be universally deployed in all types of liquids and essentially solves any application scenario without adjustment.
How do you go about finding ways to further improve such a top seller?
Pfändler: We spend a lot of time on-site with users and closely share information with them. The only way to find out what they really need is to have an understanding of their processes.
Jede: Liquiphant has been optimized several times in the past. The fork was shortened, for instance, which allows it be used in narrow pipes. Digitalization now offers completely different opportunities to enhance the triedand-tested product with new innovations.
What characterizes the latest generation?
Jede: The new instruments are equipped to support the requirements of digitalization. To date, we have lacked a way to acquire other information about the sensor and the process beyond the state of operation. With completely new electronics and integrated software, we can use Heartbeat Technology to monitor, process and utilize all relevant sensor information, such as the oscillation frequency or the temperature of the electronics.
What concrete benefits does the new Liquiphant offer?
Pfändler: It offers additional safety because it constantly monitors itself in the background thanks to Heartbeat Technology. It also displays its status in real time with an LED module that is visible from a distance, or in the SmartBlue app via Bluetooth technology.
Jede: Heartbeat monitoring also detects changes such as the onset of tuning fork corrosion. By analyzing this information, operators can calculate the optimal timeframe for maintenance and service and increase the availability of the plant.
Pfändler: Additionally, the functional safety metrics have been significantly improved and are now unique in the market! Since Liquiphant was developed in line with IEC 61508, it can be used directly in SIL applications without further certification.
Will Liquiphant still have the same significance in 20 years as it has today?
Jede, Pfändler: (simultaneously) Absolutely!
Jede: The overall package of this instrument is just right, and it precisely meets the customers’ requirements. Liquiphant simplifies their lives and helps them increase productivity and optimize processes.