Emerson has introduced the Rosemount 8795 Magnetic Flow Sensor, a flow meter built specifically for hydronic cooling systems in data centers. The company says the sensor delivers accurate, repeatable flow measurement for high-reliability, mission-critical cooling applications, and is designed to simplify selecting, installing, and commissioning flow monitoring equipment in data center environments.
Bob Halgren, vice president of magnetic and vortex flow products in Emerson's measurement instrumentation business, said the sensor is meant "to help operators improve reliability, simplify deployment, and maximize cooling system performance."
Accuracy without long straight pipe runs
Data center cooling loops often do not have the long straight pipe runs that flow sensors typically need for accurate readings. The 8795 can pair with Emerson's proprietary Short Run Installation software, which the company says delivers 0.5% accuracy at zero diameters of straight pipe, based on the upstream disturbance and the distance from the electrodes, when it is set up with a compatible Rosemount Magnetic Flow Transmitter. Emerson said that capability is an industry first, since other magnetic flow meters need either a sensor built with multiple electrodes or a reduced bore to reach a similar result.
At sites with longer straight runs, of 5U/2D or more, the sensor can instead pair with any compatible Rosemount transmitter for 0.2 percent, plus or minus 2 mm/s, accuracy for monitoring and control of critical cooling loops. Built-in diagnostics and verification tools, available with every compatible transmitter, are meant to cut commissioning risk and give operators ongoing confidence in system performance.
Built for chilled water and glycol loops
The sensor is optimized for chilled water and water glycol cooling loops and covers the 2-inch to 18-inch line sizes common in data centers. Emerson cites 0.1% repeatability, feeding data to building management systems and data center infrastructure management platforms that calculate water, cooling, and power usage effectiveness.
Its wetted parts, a PTFE liner and stainless-steel electrodes, were chosen for thermal management duty in primary, closed-loop cooling systems. Other specifications include:
- No moving parts
- A minimum fluid conductivity of 5 microsiemens per centimeter
- Dual 4-20mA plus Modbus output
- Universal power for AC or DC use
- Integral or remote transmitter mounting
Emerson said the 8795 adds enhanced software and simpler ordering to its existing magnetic flow meter lineup, and that its global supply chain is built to shorten lead times at the scale data centers require.
