Motion sensor vs pir

Hello,
Until now, i only have aeotec multisensor to determine if someone is in a room or not. The problem is that lights are turned off after a few minutes even if someone is still in the room.

Will PIR solve this problem?
Does PIR work in a different way than motion sensors?

No. Best method is detect the person in room and wait some default period before make assumption( they left room or they still in room like sleeping). You nay combine this info with other sensor to make more fine guess about current occupant state but in the end it is guess. Object detection with camera or radio wave sonar could help.

PIR= passive infrared
Basically spreads beams in room and wait for object to interrupt beam
If person sitting in room it will not trigger. Only trigger when object moving across beam in room

Motion detector is reall generic term that will include sensor like PIR and may include other like sonic motion sensor

Your multisensor is also a PIR (passive infrared sensor)

Most of them are made with a pyroelectric sensor that detects temperature in small zones. In front is a grid of small fresnel lenses. This makes any objects hit the sensors in different patterns. When an object moves the IR levels detected are different and this is what triggers the sensor.

A motion IR sensor vs a presence IR sensor is more a marketing term. They are all motion sensors, but a presence sensor typically has more and smaller zones so that it takes less movement to trigger them. But even the most sensitive sensors will not detect if you are sitting 100 still. The way they work is that they count on having a timeout which is longer than what a normal person can be still.

The more zones a sensors has, the less motion is required to be detected. The closer you are to the sensor, the less motion is required.

I have a few rooms where I have been challenged with having enough sensitivity to keep the lights on. In my office and in my hobbyroom. In the office I may sit and type or listen to a meeting, and in my workshop I sit and solder. And then suddenly the lights are off. In both cases the trick was to add an extra sensor which is located where I sit and so my arms trigger motion even by the smallest movement with the hands.

And no matter what. The longer the on period, the less likely you are to sit still too long. And in practical the electricity saving is the same whether you have a 2 minute timeout or a 10 minute timeout. It is also important that the timeout starts when the motion detection ends. All PIR detectors have a period after detection where they are on. And sometimes also a short time before they will go on again after off. Your timeout must be significantly longer than this. My experience is that 10 minutes work well.

Last trick is, if you have lights that can transition off, then use that with a 20 to 30 second transition. This way, if you sit too still, you do not end up in the dark, but just have to move a little when you see the lights go dim.

Below is my workshop automation with two PIR sensors and a 20 second transition time. Timeout is 600 seconds or 10 minutes.

- id: 'Workshop_on_with_Motion'
  alias: 'Workshop on with Motion'
  initial_state: true
  mode: restart
  max_exceeded: silent
  trigger:
    - platform: state
      entity_id: binary_sensor.workshop_motion
      from: "off"
      to: "on"
    - platform: state
      entity_id: binary_sensor.workbench_motion
      from: "off"
      to: "on"
  action:
    - choose:
      - conditions:
          - condition: state
            entity_id: light.workshop
            state: 'off'
        sequence:
          - service: light.turn_on
            data:
              entity_id:
                - light.workshop
              brightness_pct: 100
    - wait_template: >
        {{ is_state('binary_sensor.workshop_motion', 'off') and is_state('binary_sensor.workbench_motion', 'off') }}
    - delay: 600
    - service: light.turn_off
      data:
        entity_id:
          - light.workshop
        transition: 20

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