Highly Accurate Differential Pressure Transmitter with Double Sensor

Opening up new possibilities for level measurement

  • Differential Pressure Transmiiter Series PRD-33 X with double sensor
    Differential Pressure Transmiiter Series PRD-33 X with double sensor

KELLER AG für Druckmesstechnik is launching the Series PRD-33 X. This differential pressure transmitter features a double sensor for measuring the differential and line pressure independently, highly accurate measurements and a high overload resistance. Combining these benefits opens up new possibilities, such as measuring the levels in liquefied gas tanks safely, accurately and at a reasonable price.
The PRD-33 X has two independent sensors and measures the line pressure as well as the differential pressure. The transmitter achieves its particularly high accuracy level of up to ±0.05% FS due to its calibration over the entire pressure and temperature range. The mathematical model calculated in this way corrects all repeatable errors. The high level of accuracy is therefore guaranteed as an error band within the overall compensated range. The floating assembly of the sensor unit provides the ideal protection from external forces during installation.

Application example: measuring the level in pressure tanks
Pressure tanks impose particular requirements on pressure transmitters. The closed systems require two measurements to deter­mine the level: one for the tank pressure and one for the liquid pressure. Thanks to its two sensors, the PRD-33 X achieves this in one measurement process. All transmitter parts that come into contact with the medium are made from high-quality materials such as stainless steel AISI 316L, silicone, gold and silicon. The PRD-33 X is therefore perfectly suitable for use with (liquid) oxygen, argon, nitrogen, helium and carbon dioxide.

Very high overload resistance, even in the smallest pressure ranges
The requirements become even more extensive with cryogenic liquefied gases. Tanks that are smaller than three metres can have a differential pressure range of only 200 mbar - with a line pressure of up to 32 bar. With its line pressure compensation of 0...40 bar, the PRD-33 X can tackle this challenging combination with ease. When the tank is being filled or the valve is being used, the entire tank pressure can hit one side of the differential pressure transmitter. The PRD-33 X also copes brilliantly with the resulting 32 bar uneven overloading with its overload resistance of ±35 bar.

Simple configuration with free software
The PRD-33 X can be supplied with various electrical connections and has a digital RS485 interface. In addition to the process values of both pressure sensors, this provides further information such as pressure ranges, filter settings and the serial number. The software supplied with the PRD-33 X enables the transmitter to be configured and controlled and data to be saved easily. Using it in combi­nation with a KELLER remote data transmission module or indicator further extends its range of functions and possible applications.


Company Profile

KELLER AG für Druckmesstechnik

· Europe's leading manufacturer of isolated pressure transducers and transmitters
· Pressure ranges from 5 mbar to 2000 bar
· High volumes at low prices, great flexibility, highest accuracies
· Production of more than one million pressure transducers and transmitters per year
· KELLER is certified according to ISO 9001:2008

KELLER AG für Druckmesstechnik, headquartered in Winterthur (Switzerland), is Europe's leading manufacturer of isolated pressure transducers and transmitters. The company, which has a global workforce of around 400 employees, was founded in 1974 by Hannes W. Keller, a graduate in physics and the inventor of the integrated silicon measuring cell. The entire value creation, from production of the individual parts and calibration of the sensor through to the final inspection of the finished products, takes place at the headquarters in Winterthur. All KELLER AG products are therefore "Made in Switzerland".

KELLER AG piezoresistive pressure sensors have impressively high precision and pressure ranges from 5 mbar to 2000 bar. In addition to more than 500 standard products, the company also develops and produces numerous customised solutions. Using state-of-the-art, automated manufacturing processes, large runs of industrial OEM transducers as well as special design versions in very small quantities are produced in more than 35 highly-specialised machining islands, resulting in more than one million pressure transducers and transmitters per year. The high quantities mean that we can keep prices low despite complex production processes and stringent quality requirements.

The KELLER AG product range includes digital manometers, level probes, data loggers, remote transmission units and pressure calibrators. Digital display equipment completes our wide range. The application areas for our pressure transducers are just as broad as our product range. For example, they regulate the internal cabin pressure in aircrafts, ensure the smooth switchover from natural gas to petrol in hybrid vehicles and are used as reference sensors in laboratory technology. KELLER special sensors, such as modular pressure catheters and other miniature transducers, are especially popular among researchers.

KELLER AG für Druckmesstechnik, including KELLER Ges. für Druckmesstechnik mbH Jestetten, is certified to ISO 9001:2008. The traceability of the measurement variables to national standards is therefore ensured.

Graduated in political sciences and international relations in Paris, Anis joined the team in early 2019. Editor for IEN Europe and the new digital magazine AI IEN, he is a new tech enthusiast. Also passionate about sports, music, cultures and languages. 

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