Omron's new airflow sensors detect clogged filters

Citation

(2005), "Omron's new airflow sensors detect clogged filters", Sensor Review, Vol. 25 No. 3. https://doi.org/10.1108/sr.2005.08725cad.004

Omron's new airflow sensors detect clogged filters

Omron's new airflow sensors detect clogged filters

Keywords: Sensors, MEMS

Omron has further strengthened its family of MEMS-based airflow sensors with the introduction of two new versions incorporating a patent pending dust segregation system (DSS) that helps to maintain sensing performance in a variety of applications. These include the detection of clogged air intake filters and air velocity flows in office automation (OA) equipment, including consumer portable products such as PC projectors and other PC related peripherals, domestic products like air purifiers, coolers and many other more conventional HVAC products requiring to monitor airflow efficiency for product protection and environmental comfort. D6F-W may also be considered as a suitable alternative to single point Pitot tubes and thermal dispersion sensors in heating ducts and building/ environmental management systems.

Omron's D6F-W01A1 and D6F- W04A1, 39 [(L)×20 (W)×9mm (H)] airflow sensors can measure air velocity from 0-1 to 0-4m/s with an accuracy of ± 5 per cent full-scale deflection (Plate 4). Each is supplied as standard, optimally adjusted at the factory so easy and rapid user application is guaranteed. Precision performance is maintained utilising an integral dust management system consisting of two small circular chambers. Their complementary function acts like a passive centrifuge, helping to separate up to 93 per cent of dry air borne particulates (simulation result) normally encountered in both domestic and commercial environments. The air containing the heavy dust particles is exhausted through a dust outlet. The resulting “balanced” airflow continues on its way to a specially developed chamber where it is “laminated” ensuring an extremely stable measurement characteristic.

Plate 4 Omron's D6F-W features Dust Segregation System to ensure precision performance in HVAC applications

Inside each D6F-W is a highly sensitive MEMS flow chip that is only (1.5)²×0.5mm thick. The MEMS flow chip has two thermopiles on either side of a tiny heater element used to measure the deviations in heat symmetry caused by the passing gas flow in either direction. A thin layer of insulating film protects the sensor chip from exposure to the gas. When there is no flow, temperature distribution concentrated around the heater is uniform. When a flow is subjected, temperature on the side of the heater facing the flow cools and on the side away from the flow, warms up (heat symmetry collapses). This difference of temperature appears as a difference in the thermopile's electromotive force, the mass flow velocity and mass flow rate can be measured.

The new D6F-W models complement Omron's existing family of MEMS flow sensors that include D6F-01A1- 110 and D6F-02A1-110 (mass airflow 1 and 2LPM), D6F-05N2-000 (mass flow of natural (town) gas/ LNG 5LPM.

For more information, please contact: Lee O'Toole, Omron Electronics Components B.V., UK & Ireland Sales Division, Helios Court, 1 Bishops Square, Hatfield Business Park, Hatfield, Hertfordshire, AL10 9NE, UK. Tel: +44 (0) 870 750 5661; Fax: +44 (0) 870 750 5662; E-mail: ukcc_sales@eu.omron.com; web site: www.omroncomponents.co.uk