KELLER AG für Druckmesstechnik has introduced the Series PRD-33 X differential pressure transmitter, which 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 per cent 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.
Pressure tanks impose particular requirements on pressure transmitters. The closed systems require two measurements to deter¬mine 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.
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.
The PRD-33 X can be supplied with various electrical connections and has a digital RS485 interface. 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 combi¬nation with a KELLER remote data transmission module or indicator further extends its range of functions and possible applications.