If it leaves the wall, you know in seconds.
Not when you get home. Not when someone finally notices. The second the frame lifts off its hook, your phone lights up — and if the sensor goes quiet after that, you hear about that too.
Find out while it's still nothing.
By the time damage is visible, it's permanent. Vokter watches the air around your paintings and whether they're still on the wall — seconds if something moves, the first day if the air turns against them. Wherever in the world you happen to be.
Damage arrives quietly.
A radiator fails in January while you're away. The room cools, the humidity climbs, and inside a week mould has taken hold on the back of the canvas — where nobody will think to look for months. Nothing looked wrong. Nothing made a sound. Vokter watches how fast conditions are moving, not just where they end up, so you hear about it on the first day, while it's still a phone call to a neighbour.
It learns your walls.
Every house has a rhythm. Sun on the south wall at two. Heating at six. Windows thrown open on the first warm Saturday in April. Vokter learns yours, and stops mentioning things that are merely Tuesday — so on the day it does speak, you believe it.
Three steps. Then you forget about it.
- 01
Stick the sensor to the back of the frame.
It's the size of a large coin. No tools, no wiring, no holes. Nothing touches the work itself.
- 02
Plug the hub in anywhere in the home.
It has its own connection — no Wi-Fi password, no router settings, no app pairing dance. It keeps working through a power cut.
- 03
Then leave it alone.
The hard limits work from the first minute. Over the following weeks Vokter also learns what normal looks like in your home — and then it goes quiet, and stays quiet, until it shouldn't be.
Built on the method museums use.
A cheap sensor gives you two fixed lines and shouts when a reading crosses one. Set them tight and your phone never stops — the afternoon sun on a south wall is enough. Set them loose and you find out far too late.
European Standard EN 15757 describes a better approach, developed for museums and historic buildings. Instead of one number for every room in every country, it starts from what this place actually does across a year, and measures everything against that. Your wall in February is not your wall in July. A single number cannot be right in both.
Vokter follows that method. It learns the slow seasonal rhythm of your room and sets its alert band around it — narrow enough to catch a real problem, wide enough to ignore a sunny Tuesday. The band moves with the year. It never moves past the limits that are wrong for any painting, anywhere.
- Your normal
- Learned from your room, following EN 15757. Sharper the longer it runs.
- Hard limits
- 40–60% humidity, 16–25°C. The band never drifts past these, no matter what your room does.
- Sudden change
- A sharp move means something has happened — a leak, an open window, a failed radiator. You hear about it the same day.
In the box
- The sensors.
- Three of them, 35 mm across and 12 mm thick, matte black or off-white. Each sits on the back of a frame or on the wall beside it, and you'll stop noticing them inside a week. Five years on one coin cell, which you can change yourself in about ten seconds.
- The hub.
- Plugs into any socket. Connects on its own — no Wi-Fi, no configuration. Covers a typical apartment; large or old houses with thick walls may need a second one, and we'll tell you before you order.
- The app.
- Live readings, full history, and the alerts. Nothing else.
Measurements
| Temperature | ±0.2 °C |
|---|---|
| Relative humidity | ±1.8 % |
| Movement | Immediate, with tilt and impact |
| Reporting | Full history every day, alerts instantly |
| Battery | 5 years, user-replaceable |
| Range | One hub covers a typical apartment |
Readings are logged every five minutes and delivered daily, so your history is complete rather than sampled. Alerts don't wait for the daily upload — they go out the moment they happen.
Vokter Home
€25 a month. Three sensors and a hub.
One sensor gives you a number. Three let you look after three different things — the painting in the living room, the wine downstairs, the cabinet you'd rather nobody opened. And where two of them do share a room, the difference between them is usually what finds the problem: an exterior wall and an interior wall can differ by several per cent of humidity, and it's the exterior one that does the damage.
Everything is included — the hardware, the connection, the app, the alerts, and replacements if anything ever fails. There's nothing to buy and no second invoice.
€300 a year. Less than you spent on the frame.
Sixty days, not thirty. Vokter spends its first weeks learning your rooms, so a month isn't long enough to judge it fairly. Take 60 days from the day it arrives. If it isn't for you, we refund everything you've paid and cover the postage both ways — no conditions, and nothing to explain.
12-month minimum term after the first 60 days. Your 14-day statutory right to withdraw applies as well and is unaffected — see Right of withdrawal.
Another sensor — €10 a month. For another room, another wall, or the piece you just brought home.
Another hub — €15 a month. For large houses, thick walls, or a second address.
Most people need Vokter Home. If what you're protecting doesn't stay in one place, read on.
Vokter Roam
€20 a month. One sensor. No hub. Goes anywhere.
Some things don't stay on a wall. A piece out on loan. A work in storage. The painting that moves with you between two houses, or the one you're not entirely sure you'll get back.
Roam carries its own connection, so it needs nothing around it — no hub, no Wi-Fi, no socket. It reports temperature, humidity and movement wherever in the world it happens to be, and unlike the wall sensors, it can tell you where that is. Indoors, roughly. Outdoors and moving, precisely.
One trade-off, stated plainly: it holds a year on a charge rather than five. Once a year, it wants an evening on a cable.
Vokter started with four of my grandfather's paintings on a bad wall. Here's the rest of it.
Questions
Will it damage the artwork?
Nothing touches the work. The sensor mounts on the back of the frame or on the wall beside it, using adhesive that removes cleanly. If you'd rather not attach anything at all, it works on a nearby shelf — slightly less precise about movement, just as good about the air.
How often will it interrupt me?
Almost never — and that's the design goal, not a happy accident. Once it has learned your rooms, most homes see a handful of alerts in a year. Anything chattier and you'd mute it, and a muted sensor is worth nothing at all.
What happens if the power goes out?
The hub has its own battery and keeps working. The sensor never needed mains power in the first place.
What if someone unplugs the hub, or takes the sensor?
You get told. Vokter expects to hear from every sensor on a schedule — silence is treated as an event, not as good news.
Can you track it if it's stolen?
With Vokter Roam, yes. It carries its own connection and reports its position in real time, across borders. Outdoors and moving, that position is precise. Indoors it's approximate, because satellite positioning doesn't work through a roof. With Vokter Home, no. The wall sensors speak through your hub, so the moment a piece leaves the building they go silent. You'll know that happened and you'll know exactly when — which gives you and the police a starting point most people don't have — but the sensor won't follow it across town. Neither stops a theft, and a sensor that's found can be removed. We'd rather tell you that now than let you discover it later.
Does it replace my insurance?
No. It's the part insurance can't do. A policy handles the loss after it happens; Vokter is about the hours before, when the situation is still fixable.
Is three sensors the right number?
Three because most homes have more than one thing worth watching, and they're rarely in the same room. A sensor doesn't much care what it's looking after: put one behind the painting, one in the wine cellar where a failed thermostat costs you a case at a time, and one on the drinks cabinet, where all you want to know is whether anybody opened it. If you have more than three, sensors are €10 a month each.
What's the difference between a Vokter sensor and Vokter Roam?
The wall sensors are small, invisible and last five years, but they need a hub in the building to speak through. Roam carries its own connection and works anywhere on earth, including in the back of a van — but it's larger, it knows roughly where it is, and it needs charging once a year. If your art stays home, you want sensors. If it travels, you want Roam.
Do I need Wi-Fi?
No. The hub brings its own connection. There is nothing to configure.
Is my data private?
The readings are yours. We don't sell them, we don't share them, and you can export or delete everything at any time.
I travel a lot. Does that change anything?
Only in that it matters more. Vokter asks nothing of you while you're gone — no checking in, no app to open, no weekly report to read. If your phone stays quiet, everything is fine. If it doesn't, you'll know in time to ask someone to go over and look.
Does it work in a summer house I'm rarely at?
That's one of the better uses for it. An unheated house in winter is exactly where humidity does its worst work, unobserved. You'll need mains power for the hub, but nothing else.
What happens when I order?
Nothing is charged, and nothing is committed. You tell us what you'd like and we reply within a working day or two with an offer — usually with a question or two about your home first, because the right number of sensors depends on the building. If the offer suits you, we send the hardware. That's when the subscription starts.
What if I change my mind?
Tell us within 60 days of delivery and we refund everything you've paid, including postage in both directions. You don't need to explain, and there's nothing to negotiate. Send the sensors back and we're done. Sixty days rather than thirty because Vokter spends its first weeks learning your rooms — a month wouldn't be a fair test of it. Separately from this, and regardless of it, you have the 14-day right to withdraw that the law gives anyone who buys at a distance.
Responsible for a building, or more than a handful of pieces? Write to us — post@vokter.art
Nobody insures the part that matters.
You know which one it is. Most people with art have one piece they'd turn back for — and it's usually not the valuable one. It's the one with a story attached. A wedding present. Something bought badly and far too early, before you knew anything, that turned out to be right.
A policy can replace a sum. It can't replace the object, and it has nothing at all to say about the slow version of losing it — the dry winters, the wall that was always a little too warm, the damage that arrives so gradually that no single day was the day it happened.
That's the part Vokter is for.
Go away for three weeks. Think about something else.
€25 a month. Ten minutes to set up. Then quiet, until there's a reason.