Ask three people-counter vendors how accurate their device is and you will get three confident percentages. Ask them how those numbers were measured and the conversation gets quieter. After many years of installing counting systems in shops, museums and offices, our honest answer is: accuracy is mostly decided at the door, not in the brochure.
What "accuracy" means for a people counter
A people counter compares its count with a manual count over the same period. If 1,000 people walked through and the device counted 980, that is 98% for that door, on that day, with that installation. Two things follow. First, the percentage is only meaningful together with the conditions it was measured under. Second, the same device can score differently at two doors.
There are also two kinds of error. Missed people (undercounting) and phantom counts (overcounting) can cancel each other out in a daily total while both being present. A counter that misses 3% and adds 3% shows a "perfect" day and a distorted hourly picture.
Four things that decide the real number
1. The sensing technology
Break-beam counters, thermal sensors, cameras and Time-of-Flight (ToF) sensors all count, but they see different things. A single break-beam cannot separate two people walking side by side. Camera systems can be very capable but bring privacy and lighting questions. ToF sensors measure distance many times per second and see a moving shape, which lets them count direction and handle groups reasonably well without capturing images. The WELLPOINT People Counter uses ToF sensing for that reason.
2. The doorway
Width matters most. A sensor rated for a doorway of up to about 2.4 m will lose people at a 4 m entrance unless several devices are linked. Glass doors, mirrors and bright sunlight facing the sensor can confuse optical systems. Doors where people stop, turn around or stand chatting inside the detection zone generate more errors than doors people walk straight through.
3. The installation
This is where most accuracy is won or lost. Mounting height, angle across the flow, distance settings and the direction setting all matter. A side-mounted counter installed at the recommended 1.2 to 1.4 m, perpendicular to the direction people walk, performs very differently from the same device stuck on at 0.8 m pointing at a wall. Following the installation guide is worth more than any headline percentage.
4. Staff and non-visitors
Staff, cleaners and deliveries walk through the same door. Whether they are "errors" depends on what you want to measure. For many uses they are a small, constant share that does not affect trends; for others, counting at a staff-free entrance or during opening hours only is the practical fix.
Why we do not print a single accuracy number on this site
Because it would be true for some doors and misleading for others. What we can say is that a correctly installed WELLPOINT People Counter delivers reliable, consistent counts at typical indoor entrances, that the detection distance is adjustable remotely so the device ignores movement beyond the doorway, and that wide entrances are handled by linking several devices. If you want a number for your door, the honest way is a short manual count after installation, which we are happy to help with.
What matters more than the last percent
- Consistency. For trends, busy hours and campaign comparisons, a counter that behaves the same way every day is more valuable than one that is occasionally perfect.
- Direction. Bidirectional IN/OUT counting is what makes occupancy possible. A one-way count cannot tell you how many people are inside.
- Timeliness. Data that arrives in minutes lets you act today. Data that arrives in a monthly report does not.
- Getting the data out. Accurate numbers locked in a dashboard are less useful than good numbers in your ERP, BI or planning tool.
A practical checklist before you buy
- Measure your entrance widths. Ask how many devices each one needs.
- Ask where the device mounts and whether your door frame or wall allows it.
- Ask what happens with sunlight, glass and reflective surfaces at your door.
- Ask how direction is set and how occupancy is calculated.
- Plan a short manual count after installation to confirm the setup.
If you want to talk through a specific entrance, tell us about it. We will say plainly whether it is an easy door or a difficult one.