Updated August 2026 · by Dynamic ID S.r.l.
On a construction site the question «who is inside right now?» sounds trivial until you really need the answer. You need it when an inspector arrives, when a client asks for attendance reporting per contractor, and in the worst case: when someone has to know how many people to evacuate and who is unaccounted for.
The paper sign-in sheet at the gate answers that question only if somebody fills it in every time, for everyone, including at six in the morning in the rain. In practice, that does not happen.
NFC — Near Field Communication — works within a few centimetres. What looks like a limitation is in fact its main strength on site: tapping is a deliberate act. You do not record an entry because somebody walked past a reader two metres away.
| Technology | Range | What it is for here |
|---|---|---|
| NFC | a few centimetres | Identify the person and read PPE, with a deliberate gesture |
| UHF RFID | up to a few metres | Read every item of PPE worn while walking through a gate, without stopping |
| BLE | tens of metres | Know which area a person is in, continuously |
| LoRaWAN | up to kilometres | Cover large sites and outdoor areas nothing else reaches, with years of battery life |
In short: NFC for who, UHF for what they are wearing, BLE for where, LoRaWAN for distance.
We have talked about NFC so far because it is the simplest and cheapest option, but it is not the only one we supply. Depending on the site we build the badge in three technologies, and often combined in the same card.
| Badge type | Battery | What it adds | When we choose it |
|---|---|---|---|
| Passive NFC | no | Identification at the gate, as a deliberate act | Short sites, tight budget, no infrastructure |
| Active BLE | yes, months | Announces itself continuously: presence by area with nothing to tap | Plants and warehouses, where you need where and not only whether |
| LoRaWAN | yes, years | Covers kilometres with few gateways; can embed GNSS and beacon scanning | Large sites, quarries, networks, outdoor and linear works |
BLE and LoRaWAN badges solve a practical limit of NFC: they require no gesture at all. Nobody has to tap anything, so «I forgot» stops being a case. In exchange they carry a battery to manage and a higher cost per unit.
In practice the combination we propose most often is NFC at the entrance, BLE for presence by area, and LoRaWAN where the site is too large for BLE to cover at a sensible cost. These are decisions made looking at the site plan, not the price list.
If the site has a defined entrance and steady traffic, a control gate changes things. It is a passage fitted with UHF RFID antennas that, as the worker walks through, reads every PPE microchip they are wearing in one pass and answers with coloured lights and an audio message: green and you go through, red if the helmet is missing or a device has expired.
The value is not the check itself, it is that the outcome is immediate and public. Nobody has to play the enforcer: the gate says no by itself, and the worker goes back for what is missing without an argument.
If instead the site is spread out, changes shape every week or has no single entrance, the gate is the wrong investment: the supervisor's phone is better.
A badge should be more than a number. In Safety-ID it carries the employing company, the training record, the expiry of medical fitness and — if the worker authorises it — information useful in an emergency: first-aid contacts, allergies, blood type.
So when somebody shows up at the gate, the question is not only «who are you» but «may you enter today?». And that is a question a paper sheet cannot answer.
How many entrances do you have, and what are they like? That decides whether you need a gate or just a smartphone. Half an hour is enough.
This page is informative and does not replace the assessment of your safety adviser.