Rosemount Transmitters Feature Real-Time Control and WirelessHART

Measuring pressure, temperature, and even volume are common processes in automation. Large processing plants may have hundreds of sensor transmitters all reporting different measurements throughout the product life cycle. These measurements are vital to ensure a quality product.

While an installation of either a pressure sensor or a level sensor typically requires a control system and miles of wiring to connect everything, Emerson has released two new transmitters that challenge this. One has an internal control system, while the other uses the WirelessHART communication protocol.

The Rosemount 4051S pressure transmitter features built-in local and real-time control functionalities. Image used courtesy of Emerson

Pressure Transmitter With Internal Control

Typically, a sensor reports a measurement with a small electrical signal. A transmitter will then convert the small electrical signals from the sensor and report them to the control system, where the amplified signal is scaled to empirical values. This topology can sometimes require costly devices and troublesome wiring.

Emerson’s new Rosemount 4051S pressure transmitter is a sensor, transmitter, and control system in one. The transmitter contains two internal relay contacts that can be configured for simple on/off logic. This logic can control pumps and beacons and signal other control systems. This feature enables technicians to configure their transmitter to operate a pump in the event of an overpressure event.

The Rosemount 4051S pressure transmitter features an easy-to-read graphical display and Bluetooth connectivity with a 50 ft radius. Image used courtesy of Emerson

Pressure, Level, and Flow Measurements

The Rosemount 4051S pressure transmitter is not your ordinary transmitter; it features models configured for pressure, flow, and level measurements. The pressure variant can measure pressure in gauge, differential, and absolute. The level model is capable of being directly mounted or remotely mounted and will work with balanced or tuned systems. The flow meter version uses differential pressure measurement to measure flow accurately.

Wireless Sensor Readings

Wirelessly transmitting level readings can considerably reduce cable runs. In large processing plants, holding vessels may be more than 100 m away from the closest control system. This layout requires special wiring, signal repeaters, and a lot of cables. With a wireless level transmitter, processing plants would only need to supply power to the transmitter, then pass processing data over a WirelessHART connection.

The Rosemount 3408 wireless level transmitter features WirelessHART connectivity. Image used courtesy of Emerson

WirelessHART Non-Contacting Radar

Emerson’s new Rosemount 3408 wireless level transmitter utilizes the latest WirelessHART communication protocol, which is based on 80 GHz modulated wave frequency technology. By using this communication technology, the level transmitter excels in conditions where other wireless devices would fail.

The wireless connection distance ranges from 225 m to 1 km (for the high-gain remote mode). Operating power only requires 12 to 35 VDC while the operating temperature ranges from -60 to 200 °C.

The transmitter’s measurement range goes from 0 to 30 m and comes in two accuracy versions: ±2 mm and ±1 mm (for the high-accuracy version). The 3408 transmitter also has a power life expectancy of up to 10 years, so users can rest assured that level measurements are stable over a long period of time.

Enhancing Industrial Processes

Emerson’s latest transmitters utilize existing technologies to help process engineers reduce operating costs by not needing a PLC or lengthy cable runs. While these technologies are not new, they are being used in novel ways. These new transmitters aim to provide a new way of connecting and controlling devices within the processing plant.