Differential Pressure Transmitters

The differential pressure transmitters of the PRD-33X series are designed for accurate measurements in low pressure ranges with very high overload on both sides. In addition to the differential pressure sensor, which may only be exposed to gases at its rear face, the devices have an additional absolute pressure sensor that measures the line pressure. Both measured values are output via the digital RS485 interface and are the ideal basis for cryogenic tank monitoring.

The DMD 331 is a differential pressure transmitter for industrial applications and is based on a piezoresistive stainless steel sensor, which can be pressurized on both sides with fluids or gases compatible with SST 1.4404 and 1.4435. The compact design allows an integration of the DMD 331 in machines and applications with limited space. The DMD 331 calculates the difference between the pressure on the positive and the negative side and converts it into a proportional electrical signal. Features: — differential pressure 0 ... 20 mbar up to 0 ... 16 bar — accuracy: 0.5 % FSO — 2 piezoresistive stainless steel sensors — differential pressure wet / wet — permissible static pressure -one sided- up to 30 times of differential pressure range — compact design — mechanical robust and relieable at dynamic pressures as well as shock and vibration

The OPTIBAR DP 7060 is a differential pressure transmitter with integrated absolute pressure measurement. It offers a high degree of modularity for various flow, hydrostatic level or process pressure applications. For DP flow measurements it can be perfectly combined with the KROHNE primary elements (e.g. orifice plates or pitot tubes). Featuring a quick response time of just 125 ms, the DP transmitter offers high accuracy and measurement stability under all process conditions. KROHNE is the only manufacturer of process instrumentation to carry out a total 3D linearization of its differential pressure transmitter. For a robust and accurate differential pressure measurement, even under changing process conditions, each OPTIBAR DP 7060 differential pressure transmitter is linearized in all three dimensions during calibration: differential pressure, ambient temperature and static pressure are taken into account in combination.

The pressure transmitter illustrated here measures differences in pressure between the two connections of the measuring element. Pressure differences can be measured with respect to a reference pressure, such as atmosphere, or to the command variable of a regulation system. Equally, however, it is possible to measure pressure differences within systems that have a high static pressure. One practical example of this would be measuring a flow rate by determining the pressure drop occurring across a metering diaphragm. The differential pressure transmitter measures in both directions and can therefore, for instance, be used on double-acting hydraulic cylinders. Its construction permits it to be used with liquid or gaseous media. Venting holes simplify installation. The robust design and the use of stainless steel make it possible to use the pressure transmitter under tough operating conditions.