Keller presents the PRD-33 X differential pressure transmitter. It has two independent sensors and measures the base pressure in addition to the differential pressure. Its accuracy of up to ±0.05 %FS is achieved through calibration over the entire pressure and temperature range. The mathematical model thus calculated corrects all reproducible errors. The floating installation of the sensor unit protects it from external forces during installation. It can be used in pressurized tanks, for example: these closed systems require two measurements to determine the fill level - one for the tank pressure and one for the liquid pressure. Thanks to the two sensors, the differential pressure transmitter can do this in a single measurement process. All transmitter parts with medium contact are made of materials such as AISI 316L stainless steel, silicone, gold and silicon. This makes the device suitable for use with (liquid) oxygen, argon, nitrogen, helium and carbon dioxide. The basic pressure compensation of the device is specified at 0 to 40 bar, the overload resistance at ±35 bar. The transmitter is available with various electrical connections. It has a digital RS485 interface which, in addition to the process values of the two pressure sensors, also provides information such as pressure ranges, filter settings and serial number.