Why Sensor Choice Matters For Automated Doors
Imagine a busy supermarket entrance on a wet Monday morning: shoppers with buggies, a wheelchair user and a delivery driver all arrive at once. The wrong sensor mix means slammed doors, repeated holds and wasted heating — the right mix keeps traffic moving and people safe. This article is for facilities managers, installers and building owners in the UK who need practical guidance on picking and configuring sensors for compliance, accessibility and reliability.
In our experience, a clear zone strategy and the correct device types are the difference between a trouble-free door and one that generates complaints. Read on to learn which sensors do what, how to set detection zones, what to test during commissioning, and simple next steps you can take on site today. For legal and safety detail see our BS EN 16005 safety audit checklist.
Sensor Types At A Glance: Activation Vs Presence
Activation sensors detect approach and tell the operator to open (radar, PIR). Presence sensors protect the leaf and threshold and detect stationary or slow-moving users (active IR, LiDAR). A compliant installation pairs both so approach opening hands over to threshold protection.
A common issue we see is relying on activation alone; doors will open but can leave safety gaps at the leaf. When integrating with commercial access control, safety must always override the opening cycle.
Radar (Microwave) Sensors
Radar senses motion by Doppler shift and is ideal for busy external approaches and wide thresholds. It does not see stationary users, so always pair it with a presence sensor. False triggers from wind, trolleys or nearby traffic are common unless you trim range and aim carefully.
Fit at the manufacturer’s recommended height, tilt to create a clear approach line and reduce range so the pavement or road isn’t picked up. Enable cross-traffic suppression in concourses and lower sensitivity settings for prams and mobility scooters. See examples for exterior commercial entrances for typical placements.
This image was generated with AI and may not always represent the product or service exactly.
Infrared Sensors: Passive (PIR) And Active IR
PIR detects heat movement and suits internal approaches and smaller entrances. Avoid pointing PIR at draughts, heaters or sunlit lobbies. Active IR emits beams or grids and detects objects regardless of temperature, so it’s better for threshold and leaf protection and touchless hygiene areas.
Set a crisp threshold line and expand presence close to the leaf for slower users. Use background-learn features to reduce reflections from glossy floors. If you’re in a healthcare or food environment, active IR is a strong hygiene-led option.
LiDAR 3D Presence Curtains
LiDAR maps precise distance in 3D to create safety curtains that reliably see dark clothing, luggage, wheelchairs and canes. It excels on swing doors where the leaf sweeps and on narrow sliding thresholds. Teach-in with the lobby clear and mask shelving to avoid false holds.
Expand low zones to capture cane tips and wheels, then verify with BS EN 16005 test bodies. For DDA considerations and layout guidance, consult our DDA-compliant doors guidance.
Safety Edges And Supplementary Protections
Safety edges are pressure-sensitive strips fitted to leading or pocket edges. They stop or reverse the operator on contact and act as a last line of defence — not a substitute for presence sensing. Use monitored circuits and test them routinely.
On higher-risk doors, pair edges with IR or LiDAR to add redundancy and reduce the chance of contact. A common issue we see is edges that are disconnected or poorly adjusted; include them in every service checklist.
What Most People Get Wrong
Most installers focus on a single sensor type to save time. That often solves one problem but creates another — for example, radar without threshold presence leaves stationary users unprotected. Plan zones first, then choose sensors that cover each function.
Setting Detection Zones For Automatic Sliding Doors
Aim activation along the approach, not across the concourse. Hand off to presence coverage at the threshold and extend presence across the full width, including side screens, to catch lateral movement. Enable cross-traffic immunity and walking-speed filters to reduce false openings.
Allow lower, longer presence zones for trolleys, prams and mobility scooters. Balance hold-open time with actual traffic and heat-loss concerns; use night modes or reduced sensitivity outside peak hours.
This image was generated with AI and may not always represent the product or service exactly.
Setting Detection Zones For Automatic Swing Doors
Avoid picking up movement down corridors beyond the doorway. Aim approach sensors to capture only those intending to use the door and provide presence protection across the swing path and near hinges where trapping risk is highest.
For low-energy doors, reduce opening speed and confirm stopping distances with prams and mobility aids. For power-operated doors, LiDAR or active IR helps keep the sweep clear and verifies no-contact operation at the latch side.
Integrating Sensors With Access Control And Locks
Controllers must sequence readers, request-to-exit devices, sensors and the operator: unlock, confirm a clear area, then drive the door and re-lock only after presence is clear. Choose fail-safe or fail-secure locks according to the door’s role and means of egress.
Touchless wave switches suit hygiene-focused sites; push-to-open is better for assisted entry. Always ensure emergency egress overrides normal logic and that timed delays prevent latches striking a closing leaf.
Commissioning, Testing And Maintenance
Commission with a formal checklist: teach-in, verify detection zones with test bodies, check stop/reverse performance and record results. In our experience, logging results saves time at renewal and during fault diagnosis. Users should perform simple daily checks and report faults promptly.
Retune for seasonal changes — glare, heating, wind and falling leaves affect sensors. Clean optics, check alignment and inspect safety edges. For typical service intervals and scope, see our guidance on how often automatic doors should be serviced.
When This Doesn’t Apply
If a door is purely manual with no powered operator, these sensor recommendations do not apply. Equally, very low-risk, single-person domestic interior doors often only need simple PIR activation rather than full presence protection.
Choosing The Right Mix And Next Steps
Start with a site-specific risk assessment that covers traffic type, approach lines, lighting, access control and door type. Small upgrades — adding LiDAR to an older swing door or refreshing presence on aluminium entrance doors — often deliver big improvements in safety and comfort.
Access Automation designs, installs and commissions sensor packages for commercial and domestic sites. Speak to our engineers for a tailored plan and a clear list of recommended hardware and commissioning tests.
Quick Checklist
- Complete a risk assessment and sketch approach lines
- Pair activation (radar/PIR) with presence (IR/LiDAR)
- Teach-in sensors with the lobby clear and mask irrelevant objects
- Verify stop/reverse with appropriate test bodies and wheelchairs
- Log commissioning results and schedule regular servicing
FAQs
Can I Retrofit Better Sensors To An Existing Door?
Often yes. A site survey will confirm compatibility, mounting and wiring. In our experience, many operators can upgrade activation or add LiDAR without replacing the operator.
How Do I Reduce False Openings From Cross-Traffic?
Re-aim activation sensors along the approach, trim their range, enable cross-traffic suppression and add presence sensors at the threshold to avoid unnecessary openings.
Do I Need Safety Edges If I Have LiDAR?
Yes for higher-risk doors. Edges act as a fail-safe and should be monitored and tested alongside presence sensors to meet safety standards.
How Often Should My Automatic Doors Be Serviced?
Service frequency depends on usage. Many sites benefit from two services a year; high-traffic or critical environments may need quarterly visits and more frequent optic cleaning.