New digital flow sensor

Omron Electronic Components has added a new digital flow sensor offering exceptionally high accuracy and repeatability in monitoring low air flows. The sensor is an ideal alternative to a differential pressure sensor for optimising energy efficiency in air conditioning and ventilation systems, like variable air volume (VAV) and heat recovery unit systems (HRU) or for use in high quality medical equipment and industrial applications.

Based on Omron's  MEMS thermal flow sensor chip, the new Omron D6F-PH provides better accuracy and repeatability than standard differential pressure sensors especially in low flow conditions. It is capable of measuring with superior sensitivity and reproducibility in these environments and with a wider pressure range than the commonly used capacitance-type and piezoelectric-type differential pressure sensors. Embedded ASICs carry out digital correction (linearity and temperature correction) making the D6F-PH more precise and less influenced by temperature than conventional analogue output sensors.

Features of the sensor include a new digital correction algorithm that achieves 3% R.D. precision. The sensor’s flow impedance has been increased, to reduce the influence of the bypass pipe length and diameter and give more stable measurements. The D6F-PH is suitable for use in a bypass configuration where the small differential pressure generated by orifice or flow restrictor is correlated to high volumetric flow in main duct. The sensor is available from Omron in three versions, with measurement ranges from 0-250Pa, +/-50Pa and +/-500Pa.

Current consumption is just 6mA with no load at supply voltage Vcc of 3.3VDC. The sensor features a digital I2C interface with 12 bit pre-set resolution.

The new sensor is exceptionally compact, with dimensions of just 26mm x 22mm x 18mm as a result of the new flow path design. Omron’s D6F-PH digital differential pressure sensor can optionally be supplied pre-set to provide temperature measurement or failure detection functions.