Difficulty: expert

A Sensor Plan is a document that shows all stakeholders (Facility Managers, IT, Installation partner, …) where sensors and other hardware will be installed, taking into account sensor detection areas, obstructions etc.

In the course of a Workplace Analytics project, the Sensor Plan will provide concrete examples and bring forward discussion topics.

Requirements

Following information is required to set up a good sensor plan:

• Ceiling heights

• Latest floor plan with latest furniture drawings

• Superposition Reflected Ceiling Plan (RCP) file, which will provide information on ceiling height, type of ceiling and ideally also information on where light fixtures are installed, where to find HVAC, AC ducts etc (superposition = to reflect all elements on the ceiling that may occlude or interfere with the sensor detection area)

• Table design information sheets (material, length, depth, where are cable trays positioned, ...)

• Knowing heights of table partitioning: the higher, the more they will interrupt the detection area

• Materials of the walls (glass, fabric) , important for

  • rooms smaller than 4x4m and for displays (where can they be attached?)

  • pointgrab could see trough glass, so keep count area 0.5m away from glass

• if possible: videos or pictures that show the materials of the walls (glass, fabric), information on ceiling fabric, big obstructions like chandeliers or other

Means of Communication between all stakeholders

A Sensor plan can be used as means of communication between all stakeholders on

• Types of sensors and hardware to be installed (facility managers or technicians on site might not have been part of procurement process, so depending on for example headcount kind of sensor, you need to provide cabling/a hole in the ceiling; displays need cabling etc)

• Number of sensors and other hardware to be installed

• Installation location of sensors and hardware (for example where the hole needs to be in the ceiling compared to the detection area)

• Room numbers / names for each meeting room/bubble/work place/comfort area that will be covered by sensors

Parts of a good sensor plan

• Possible version control (version, date, contributor, changes made)

• Project context (any possible on-site information that is relevant to any of the stakeholders; for example a hospital context, trading floors with limited access etc)

• Workplace Analytics Scope: Number of sensors, hardware touch points

• Comments

• Sensor placement

  • (Needs to be based on latest floor plans! Ideally including latest furniture drawings)

  • Sensor plans of different floors, incl

    • Numbers of different sensors for each floor

    • For headcount and motion sensors for meeting rooms: based on the ceiling / installation heights, you can define the detection area (remember that the Device is always in the middle of the Detection Area, which is measured at ground level); see below chapter on Best Practices of Determining the Detection Area + following pages for more information:

      • Pointgrab Height ~ Detection Area: detection area is a rectangle

      • VergeSense Height ~ Detection Area: detection area is a rectangle

      • Motion Tabs Height ~ Detection Area: detection area is an ellipse

    • For comfort sensors: zone covered per sensor (realize that a sensor only tracks the comfort in the spot of installation, so be mindful of not making the "covered zone" not too large. Best practice is not to group workplaces of which some are facing the sun in the morning with workplaces that get the afternoon sun)

  • Headcount installation direction: Sensors are displayed as circular icons on the floor plan, with an arrow pointing in their view direction (general convention is either pointing upward or to the right of the sensor plan).

Determining Detection Area: Best Practices

• Mind that the detection area is measured on floor level: any person standing on the edge of the detection area might not get picked up.

  → Avoid setting up count area at the edge of the detection area. It's a best practice to include 1.5.m coverage on all sides

• For meeting rooms: Because of the above mentioned edge of the detection area & because you never know how a room might be used in future, it's best practice that the detection area should cover the whole room, even if that means adding an additional sensor to the room

• Specific for Pointgrab headcount sensors: 

  • If more than 1 sensor is used to cover an area, these will need to be "stitched" together in the software. Allow an overlap of 0.5m in the detection area of 2 sensors that lie side-by-side and need to be stitched.

  • Traffic line: 1 single sensor for 1 traffic line (this takes into account for CPU and calculations, otherwise accuracy will drop)

  • 1 single sensor can take up to 10 count areas (remember this when you set up headcount sensors to track workplaces)

  • Pointgrab can see trough glass, so keep count area 0.5m away from glass

 How do I define count areas?

A count area is where you want to track people.

Standard rule:

• 1 meeting room = 1 count area. Depending on the size of the meeting room and the installation height, more than 1 sensor might be needed to cover the count area.

• 1 workplace = 1 count area

  • a workplace count area is minimum 1m x 1m

  • a workplace count area should cover both

    • about 50cm of the front of the table (where we might track the employee that is leaning over the desk/hunched over the computer

    • at least 50 cm behind the seat (ideally more, because employees might be leaning backward or side wards talking to colleagues)

There can be exceptions, for example Training Rooms: is it more important to track the utilization of the room, or more important to track the occupancy of individual seats?

Following training room has 22 seats drawn in. If it's enough to track the room: the detection area of 2 sensors combined is enough to cover the dimensions of the room. Yet if you want to measure which seat is more popular of all 22 seats, you will need 3 sensors.

In this next example the object on the left might be just a high standing table for discussions, rather than 4 individual work spaces (as drawn in on the right).

 How do I make sure not to exceed max count areas per sensor?

Even if the Detection Area of a sensor might cover more than 8 (for VergeSense) or 10 (for Pointgrab) Count Areas, the platforms will not allow you to configure more. So you'll have to foresee more sensors in order to cover all count areas.

Example of Detection Areas for 4 headcount sensors	Example of the split in count areas (1 sensor = max 10 count areas for a Pointgrab device) for the two bottom sensors

Examples of sensor plans

This example shows "Sensor Detection Zone layout" (not yet highlighting the individual Workplace Areas that would be covered), differentiating between open spaces (pink) and closed spaces (green). This is not a must.

What is expected though, is to clearly show Headcount installation direction.

In the following example, the ceiling was very high and we needed to get creative.

Sensor plan of our own offices in the Netherlands

Examples of possible obstructions/sensor placement according to guidelines not 100% possible

Below list of examples of possible obstructions (where sensor placement according to guidelines is not 100% possible), is just to give you an idea of what you might run into.
Each kind of sensor comes with a set of installation guidelines that provide the Spacewell subscribed accuracy, but sometimes it's just not possible to follow them to the letter in all locations. Yet all stakeholders must understand that if the installation is not according to the guidelines, measurement accuracy will be impacted (which could lead to more false positives or false negatives).

These examples show how important it is to have an on-site-visit; or a lot of pictures or a walk through while on a call.

desks

• cable trays/bars under the table

concentration spaces

• covered with fabric

  • is there a table/something in another material, where the sensor would attach?

ceilings

• ceiling too high compared to max ceiling height for resp. sensor (need to think of other installation height, eg suspended cable trays)

• chandeliers or other obstructions hanging from the ceiling

• projector hanging from the ceiling

• HVAC tubes

• cable trays

• curved ceiling

• ceiling is divided into different parts/not flat

Edge cases

 Informal areas without tables

In these cases, motion tabs can only be used to monitor general presence (not individual people), see Motion sensor installation in Meeting Rooms

If you want to know how many people (utilization) are in these areas, you need to use headcount sensors.

 Informal areas with tables

In these cases, motion tabs can only be used to monitor general presence (not individual people). The tables and chairs are too “mobile”, can be moved around etc. Also, the tables are not deep enough, so it’s not possible to provide accurate details about occupancy using motion sensors.

If you want to know how many people (utilization) are in these areas, you need to use headcount sensors.

 Open Cubicles

‪Because these cubicles are open, there is a high risk of false positives. It’s possible to install a motion sensor per workplace (see Motion sensor installation at Workplaces), but make sure the quality assurance is followed and data is monitored.

 Wanting to track utilization in meeting room with motion sensors

‪In following meeting room example, it’s not possible to capture individual presence.

Depending on what is required,

• headcount sensors could provide a solution

• also motion sensor data can be used to calculate utilization, yet there are some things to keep in mind. See Utilization & Occupancy Matrix and Use Browan motion sensors for indirect utilization

Exercise

Can you identify why the example sensor plan of the second floor (with headcount sensors, motion sensors, comfort sensors and door counter sensors) is not a good sensor plan?

Answer: Even if the count areas would not go over the edges of the detection ares: In more than 1 case, the headcount sensor would cover more than 10 workplaces (highlighted in red in below image)

Search this page