Sep 26, 2026Access Control Guides
How to Choose a Microwave Sensor for High-Traffic Commercial Entrances
Supermarkets, airports and metro entrances punish the wrong sensor. What to look for in detection field shape, response behaviour and adjustment options when thousands of people pass each day.
A high-traffic entrance is the hardest environment for a door sensor. Thousands of people approach from every angle, queues form across the detection field, and every second the door spends open for nobody is heated or cooled air leaving the building. The sensor you choose decides how gracefully the entrance copes.
Open early, but only for real visitors
On a busy entrance the detection field needs to reach far enough out that the door is already opening as a person arrives — nobody should break stride. That argues for a wide, deep detection field at the planned mounting height. But the same wide field will happily detect pedestrians on the pavement and vehicles passing on the street.
The solution is an adjustable field. Many microwave sensors let the installer narrow the width, shorten the depth, or angle the detection area, through DIP switches or by adjusting the sensor head. On a shopfront with a narrow pavement, that adjustment is the difference between a door that opens for customers and one that opens for every bus that goes by.
Unidirectional detection for flow control
High-speed pedestrian doors benefit from unidirectional detection: the sensor recognises people approaching and deliberately ignores people moving away. Why does that matter? Consider a door beside a busy walkway. A bidirectional sensor opens for everyone passing in either direction. A unidirectional sensor opens only for those actually coming in, cutting pointless openings dramatically. The same logic applies to escalator sensors, where the door or gate should react to people stepping on, not people leaving.
Response behaviour and hold time
Two timing behaviours shape how the entrance feels. Detection response should be fast enough that the door starts moving before the visitor arrives — microwave sensors respond in well under a second, and minimum detectable speeds are typically specified in the datasheet (some detect movement as slow as 5 cm/s, so slow-moving elderly visitors are still seen). Hold time determines how long the door stays open after detection; adjustable hold times let you tune the trade-off between comfort and energy loss.
Stability through weather and interference
Outdoor and semi-outdoor entrances face rain, snow and wind-blown debris. Microwave technology is inherently robust here — a 24.125 GHz Doppler sensor is essentially unaffected by temperature and humidity. Quality sensors add digital filtering and background self-adaption during the first seconds after power-on, which improves reliability in changing environments. Check the operating temperature range (−20 °C to +55 °C is typical) and, for freezer-adjacent entrances, models rated for lower temperatures.
Mounting height and field size go together
Datasheets specify detection area at a reference height — a typical figure is 4 m wide by 3 m deep at 2.8 m mounting height, with maximum mounting heights commonly 3,000–4,000 mm. If your header is higher, shortlist sensors rated for that height rather than stretching a lower model beyond its specification.
Practical buying checklist for busy entrances
Before ordering, confirm: adjustable detection field (width and depth); unidirectional mode if the approach crosses other traffic; fast response with a minimum detection speed low enough for slow visitors; adjustable hold time; operating temperature range matching the site; power supply compatibility (AC/DC 12–30 V is common) and relay output type; and a supplier who can support the product through its life.
Frequently asked questions
Will one sensor cover a wide double-door entrance?
Often yes — wide-field microwave sensors cover broad entrances from a single header position. Very wide or L-shaped entrances may need two sensors with staggered fields to avoid dead zones.
How do I stop the door opening for street traffic?
Narrow the detection width and depth to the pavement edge, use unidirectional mode if the approach allows it, and angle the field so it covers the approach path rather than the street.
AURWEN's microwave sensor range includes adjustable-field and unidirectional models purpose-built for busy commercial entrances. Send us your entrance dimensions and traffic pattern for a model recommendation.
