Measuring flow in a bypass configuration

Product Announcement from Sensirion AG

The Swiss sensor manufacturer Sensirion recently added new differential pressure sensors to its proven SDP600 series. The SDP601 and SDP611 sensors are differential pressure sensors specifically calibrated for measuring mass flow in a bypass configuration.

In a bypass configuration, an orifice or a linear flow restrictor is used to generate a differential pressure in a flow channel. The resulting pressure is measured over the orifice or the linear flow component. The difference be-tween the pressures before and after the orifice correlates to the volumetric flow in the channel, depending on the specific characteristics of the flow re-striction component. The mass flow can therefore be calculated from the measured pressure drop (differential pressure) over the orifice.

A bypass configuration is highly suitable for applications where individually adapted flow channels are necessary or where small differential pressures must be measured with very high precision. Especially for HVAC applications, which often involve measuring large flow volumes, it is the ideal solution.

The sensors expand the broad product range of Sensirion's digital differential pressure sensors in the SDP600 series. Along with the other products in this series, they offer a digital I2C output and are fully calibrated and temperature compensated. Operating on the principle of calorimetric flow measurement, the CMOSens® differential pressure sensors achieve outstand-ing sensitivity and accuracy even at very low pressure differences (below 1 Pa). They also have very high long-term stability and are free from zero-point drift. Like all devices in the SDP600 series, the SDP6x1 sensors are available in two versions. The SDP601 is intended for direct threaded connection to a pressure manifold with O-ring sealing, while the SDP611 is designed for tube connection.