PIR vs Microwave Radar vs Hand-Wave Sensors — which should your product use?
Short answer: PIR is often the starting point for battery-powered cabinet and closet lights because it detects moving heat and generally needs a direct view. Microwave radar can sense through some plastic and thin panels and is generally less temperature-dependent than PIR, so placement and enclosure behaviour should be tested on the sample. Hand-wave (IR gesture) is for surfaces where motion sensing would false-trigger — you switch the light deliberately. Related model names do not mean interchangeable accessories or controls: confirm the selected build, dimensions, mounting and accessories on the quotation and sample.
The three technologies side by side
| PIR (passive infrared) | Microwave radar | Hand-wave / touch (IR gesture) | |
|---|---|---|---|
| How it works | Detects moving body heat through a Fresnel lens | Doppler radar — senses motion by reflected radio waves | Near-field IR beam detects a deliberate hand pass; touch pad cycles settings |
| Typical detection | 3–5 m range, ~120° cone (Rechargeable PIR Cabinet Light, TDL-6110X) | <3 m range, ~150° coverage (Radar Sensor Cabinet Light, TDL-6110XWB) | close-range hand sweep (Hand-Wave & Touch Cabinet Light, TDL-6110X-IR); <30 cm on the Inline Hand-Wave Toggle (TDL-7158WB-T) |
| Line of sight | Required — does not see through wood, glass or plastic | Not required — can sense through some plastics and thin panels; test the actual panel or enclosure and placement on the sample. | Required (by design — that's the point) |
| Temperature sensitivity | Weaker in warm rooms (body vs ambient contrast shrinks) | Generally less temperature-dependent than PIR | Designed for deliberate near-field activation |
| Power draw | Typically lower draw; runtime still depends on capacity, brightness, triggers and hold time | Higher than PIR (active emitter) | Low |
| Unintended activation risks | Pets, warm drafts or heaters within the field of view | Movement behind thin walls or panels can trigger it | Lower risk when the near-field activation zone is positioned and sampled correctly |
| Best for | Closets, wardrobes, drawers, stairs, hallways | Kitchens, enclosed furniture, warm rooms, hidden mounting | Desks, display shelves, workbenches, retail counters |
| TUODI models | Rechargeable PIR Cabinet Light (TDL-6110X), Detachable-Battery Sensor Light (TDL-6111), Big-Battery Sensor Light (TDL-6108A), AAA-Battery Sensor Light Bar (TDL-7120) and Folding Motion-Sensor Work Light (TD-CL05) | Radar Sensor Cabinet Light (TDL-6110XWB), Carrot Night Light (LB-01) and the radar-switch line | Hand-Wave & Touch Cabinet Light (TDL-6110X-IR) and hand-sweep 5V bars |
Decision rules that hold up in practice
- Battery-powered and inside furniture? PIR is often the starting point. A closed door normally blocks its view, which can reduce nuisance triggering; runtime still depends on capacity, brightness, triggers and hold time.
- Sensor must be hidden behind a panel, or the room runs warm? Radar can read through some plastics and thin panels and is generally less temperature-dependent than PIR. Test the panel, enclosure and placement on the sample.
- People linger near the light without wanting it on? Hand-wave offers deliberate near-field control. Test the activation distance and mounting position so ordinary movement does not cross the zone.
- Long corridors or staircases? Some quoted 2.4G wall- and foot-light configurations can link one sensor trigger across a chain. Confirm the selected models, receiver count and control setup on the quotation and sample.
- Mixed catalogue? Use the selected model and quoted build to confirm dimensions, mounting and accessories before you standardise a range or approve a sample.
Try the difference yourself
Move your cursor (or drag on touch) — you are the person in the room. The wardrobe panel on the right illustrates line-of-sight behaviour. The Inline Hand-Wave Toggle (TDL-7158WB-T) mode illustrates its 10 GHz, under-30 cm hand-wave behaviour; this demonstration is not a measured installation result. Ranges and angles shown are the published figures for the TUODI models named below each mode.
Three radar bands, three jobs
"Microwave" is not one thing in the TUODI range. 5.8 GHz is the workhorse switching band — the Plug-Through Microwave Switch (TDL-2076WB) runs on it. 10 GHz powers the short-throw hand-wave toggles (Inline Hand-Wave Toggle (TDL-7158WB-T), sensing under 30 cm — deliberate gestures, not room coverage). 24 GHz is the band the factory’s catalogued presence range uses. Note it is not the same thing as the 57–64 GHz mmWave devices the trade press calls “presence sensing” — 24 GHz sits above the millimetre-wave boundary at roughly 12.5 mm wavelength. The catalogue gives model, frequency, distance, delay and light-control steps but does not specify stationary-detection behaviour; confirm that behaviour for the exact model before specifying it. If a supplier quotes you "microwave" without a band, ask which — the three behave completely differently.
Where presence sensing fits, and where it does not
Presence sensing earns its cost only where the light, fan or air-conditioning must stay on while the person is still. A guide by application, independent of any one supplier's range:
| Application | Default choice | Presence sensing |
|---|---|---|
| Wardrobe or short cabinet | PIR, door contact or hand-wave | Usually unnecessary |
| Hotel wardrobe | Door contact or PIR | Usually unnecessary |
| Corridor or stairs | PIR with linked control | Only for specific cases |
| Battery cabinet bar | PIR | A premium experiment, not a default |
| Office desk or meeting room | PIR plus presence | Strong fit |
| Bathroom or toilet | PIR plus presence | Strong fit; manage the IP rating and false triggers |
Start with wired or low-voltage installations and real project use cases. Battery-powered presence products come last, because runtime, price and compliance all have to work at once.
Three checks before choosing a sensor
- Specifying radar for wardrobes. Radar can sense through some wardrobe doors or panels, so a closed door may not stop detection. Test the actual door material, sensor position and sensitivity before deciding whether radar suits the installation.
- Judging PIR range from the datasheet alone. Mounting height, orientation and ambient temperature all change effective range. Tell us the mounting position and we'll confirm real-world behaviour before you commit.
- Ignoring hold time and daylight threshold. Some catalogued sensor models list an 18–30 s hold time or daylight control; availability and adjustment method vary by model. Confirm the selected model's hold time, light-control setting and any separate receiver or control accessory on the quotation and sample.