Pressure/differential pressure transmitters are typically used in the oil, petrochemical, and chemical industries to measure liquid, gas, and steam flow rates as well as liquid levels in tanks.
Yokogawa offers 45+ years experience in the development, design, and manufacture of pressure sensors and pressure transmitters. The DPharp series of digital pressure transmitters use a "differential pressure high accuracy resonance" (DPharp) sensor that represents one of the most revolutionary advances in transmitter technology.
Differential pressure level measurement has an enemy- temperature. Temperature can have a negative effect on the accuracy of level measurement. This article covers why temperature has this effect and how it can be reduced.
Larger diameter diaphragms have lower spring rates compared to smaller diameter diaphragms. Consequently, they are more flexible. As fill fluids contract and expand with temperature gradients from the process and ambient conditions, the larger diameter diaphragm can deflect without conveying a pressure change to the sensor. The smaller diameter, rigid diaphragm will not deflect as much and will cause drift in the pressure sensor reading proportional to the temperature change. This drift is usually small in magnitude.
Generally, you should order the bracket that is offered on the manifold, because if the transmitter needs to be disconnected, you don’t have to undo the piping or detach the flanged connection depending on the manifold type. However, make sure that the bracket used is feasible for your installation. Certain brackets have more configuration abilities than others. Pipe mount brackets are offered on manifolds from Parker PGI and Anderson Greenwood Division of Pentair.
Yokogawa diaphragm seal systems are available with an optional Flushing Ring. A flushing ring is metal donut-shaped ring installed between the seal and the customer process connection. It is a wetted part. The ring has a port(s) that can be used to flush the surface of the diaphragm during cleaning. The ports are threaded and available in either ¼-inch or ½-inch sizes. The ports are available with extensions to make them easier to reach. The ring may also have ring holders to ensure the entire assembly aligns correctly to prevent leaks.
The ring can be referred to as a Calibration Ring. The flushing ports on the side of the ring allow the user to apply a calibration pressure and consequently calibrate the unit against that pressure. Calibration is accomplished by sandwiching the calibration ring between the remote seal and a blank process flange.
The ring can also serve as a reducer, a spacer, or a heat sink.
The ring is available as part of the diaphragm seal model code or as a separate line item.
Download this eBook and learn:
Looking for more information on our people, technology and solutions?