Failed external lighting
Car parks, yards, paths and loading bays should be lit after dusk. The tag reports the first night they are not, so the fault is found by data and not by a complaint or an accident.
Light level monitoring tag
The ZARC light level tag reports how bright a space is, in lux and in real time, and alerts when it is dark where it should be lit or lit where it should be dark. It reads the light itself, not the switch, so it works with every kind of lamp, fitting and control system. It is fitted in minutes, runs on its own battery and needs no connection to the lighting.
01
What it reports
The tag reads the light falling on it continuously and reports in lux at the interval set for the site, down to every minute. Each report can carry the current level and the maximum, minimum and average for that interval.
It reports the result, not the instruction. A lighting controller can show a circuit as on while the lamp has failed, a timer has drifted or a breaker has tripped. The tag reports whether light is reaching the place it is meant to reach.
Two limits do most of the work. A low limit raises an alert when a space that should be lit goes dark. A high limit raises one when a space that should be dark is lit, which usually means a door has been opened or a light has been left on. Time-of-day rules keep daylight from confusing either.
The tag carries its own battery and its own radio, so it keeps reporting when the lighting circuit it watches has lost power. It is a monitoring tag: it does not replace emergency lighting tests or a lighting survey.
02
Applications
Light is a simple signal that answers several different questions, depending on where the tag sits. The uses below are the common ones; the tag works wherever lit or dark means something.
Lights left on
Offices, classrooms and stores lit all night or all weekend show on the dashboard as lit hours per day. The record puts a number on the waste and shows whether a fix has held.
Light where it should be dark
The inside of a cabinet, kiosk, store or plant room is normally dark. Light inside means it has been opened, and the alert carries the time.
Empty property
Light in a void building is a sign that someone is inside, or that a visit ended with the lights left on. It is an indicator alongside other tags, not a certified intruder alarm.
Warning lamps and obstruction lights
A tag beside a lamp reports whether it is lit. On remote structures that is complementary monitoring between inspections; it does not replace the lamp's own monitoring where a regulation requires it.
Cold rooms and stores
A light left on inside a cold room adds heat and usually means the door was left open too. The light level tag catches it beside the temperature reading.
Stairs, corridors and routes
General lighting on the routes people rely on, reported the day it fails. This is monitoring of normal lighting; it does not replace emergency lighting tests.
Growing, livestock and display
Light held within a range for plants, animal housing or displays, with a record of the hours delivered each day.
Collections and archives
Light fades paper, textiles and pigment. A continuous record shows the exposure an item has had and whether blinds and lighting rules are being kept.
A simple occupancy signal
Where lights follow people, light level shows when a room or building is in use, without a camera and without identifying anyone.
03
Where it can go
The tag reads the light at the point where it is fixed, so position decides what it tells you. Typical positions:
Beneath a luminaire
Directly under one fitting or row, to confirm that it is working.
At working height
On a wall or shelf, for the level people actually work in.
Inside enclosures
In a cabinet, kiosk or store that is normally dark, facing the door.
Outdoors, sheltered
Under a canopy or eave facing the lit area, in an enclosure specified for the location.
Beside a lamp
Close to a warning lamp or obstruction light, shielded from other light.
Near a window
To record daylight, for comparison with the lit level indoors.
04
In the dashboard
Every tag shows its live light level and a trend from the last hour to the last year. The dashboard works out lit and dark hours for each day, the maximum, minimum and average over any period, and how long a space has spent outside its limits. The car park that went dark at 2 am and the office lit every Sunday are both plain on the graph. Records export for energy reports, maintenance files and audits.
Limits are set per tag: low, high, duration and time of day. When one is crossed the alert is raised in real time and goes by email or SMS, and through an app where required, to the people you name, with escalation to further contacts.
- Live lux for every tag, grouped by site
- Lit and dark hours for each day
- Trend graphs from one hour to one year
- Low-light and high-light limits per tag
- Time-of-day rules, so dark at noon is not an alert
- Time spent outside each limit
- Buildings and sites compared side by side
- Every alert logged with the reading that raised it
- Records exported for energy and maintenance reports
- A tag that misses its reporting interval is flagged
05
Industries
Light level tags suit estates with lighting nobody is on site to check, including:
Facilities management
Lighting faults found by data, not by complaint.
Local government and public sector
Depots, car parks, schools and public buildings.
Telecoms infrastructure
Compounds, cabinets and lamps on remote structures.
Logistics and supply chain
Yards and warehouses lit through the night.
Buildings and estates
Common areas, plant rooms and stores.
Transport
Stations, depots and equipment rooms.
06
Technical specification
| Parameter | Specification |
|---|---|
| Measurement | Light level, read continuously and reported in real time |
| Sensor | Light sensor on the face of the tag |
| Units | lux |
| Values reported | Current level, maximum, minimum and average for each reporting interval |
| Range and accuracy | Specified to the requirement |
| Reporting interval | Configurable, down to every minute |
| Low-light alerts | Dark where a space should be lit |
| High-light alerts | Lit where a space should be dark |
| Duration alerts | Time lit or dark beyond a period you set |
| Time-of-day limits | Separate limits for day and night |
| Alert delivery | Dashboard, email or SMS; app where required |
| Recipients | Named people and groups, with escalation to further contacts |
| Missed reports | A tag that misses its reporting interval is flagged in the dashboard |
| Gateway power loss | Raises its own platform alert |
| Dashboard | Live level, trends, lit and dark hours per day, max/min/average; configured to your requirement |
| Records | Every reading and alert time-stamped and exportable |
| Data | Full reading history; UK-hosted or on servers on your own site |
| Power | Internal battery, up to five years depending on reporting interval |
| Independence | Keeps reporting when the lighting circuit has lost power |
| Radio | 433 MHz, one-way (transmit only) |
| Radio range | Site-dependent; confirmed by site survey |
| Mounting | Wall, ceiling, shelf, beside a lamp or inside an enclosure |
| Environment | Indoor, or outdoor in a sheltered position; enclosure specified to the location |
| Enclosure | Standard or built to the site; bespoke moulding for volume orders |
| Charges | No per-alert, per-user or licence charges |
| Manufacture | Made to order in the UK |
| Certification | CE marked |
07
From requirement to live alerts
Requirement
Tell us which spaces should be lit, which should be dark, and at what hours. That sets the positions and the limits.
Configuration
Tags are built to order with the reporting interval, limits and time-of-day rules for each position.
Fitting
Each tag is fixed where the light falls. Nothing is connected to the lighting circuit or its controls.
Commissioning
Lights are switched on and off with the dashboard open, so each limit is set against the real lit and dark levels, and alert routes are tested.
Ready to get started? Every deployment begins with a site survey.
Book a site survey08
How it reports
Readings travel over 433 MHz radio from the tag to a ZARC gateway, and from the gateway to the dashboard, where limits and time-of-day rules are checked. The tag only transmits; it has no receiver, so nothing can reach it over the air. Because it carries its own battery and radio, it reports the dark that follows a lighting circuit losing power.
Related tags
Sound level
How loud the same space is, and whether plant is running.
PIR motion
Movement of people in a space.
Door state
A door or hatch open, closed or left ajar.
Power failure
Loss of mains to the circuit itself.
Questions we answer most.
What does the light level tag tell me?
Whether a space is lit or dark and how bright it is, as a lux reading on a live dashboard.
Can it tell me a light has failed?
Yes. A space that should be lit and reads dark raises an alert.
Does it connect to the lighting system?
No. It reads the light itself, so it works with every type of lamp, fitting and control system.
Will daylight confuse it?
Time-of-day rules and positioning deal with it. A tag under a fitting at night reads that fitting.
Can it show lights left on?
Yes. The dashboard shows lit hours for each day, including nights and weekends.
Can it tell me a cabinet has been opened?
Yes, where the inside is normally dark. For a direct reading of the door itself, the door state tag is the better choice.
Does it keep working in a power cut?
Yes. It has its own battery and radio, so it reports the dark that follows a lighting circuit losing power.
Is it an emergency lighting test?
No. It monitors normal lighting and does not replace emergency lighting tests.
Does it work outdoors?
Yes, in a sheltered position with an enclosure specified for the location.
How is it powered?
By an internal battery lasting up to five years, depending on reporting interval.
How fast are alerts?
Alerts are raised in real time, as soon as the tag reports a level outside your limits.
Looking for something else?
We work with any sensor for any application.
Most sensing needs are met by a tag we already build, configured for your equipment. If yours needs a sensor or interface we don't list, we have the engineering to build it. Tell us what you need to measure, and we will tell you how we would do it.
Discuss your requirementDiscuss a monitoring
or alerting solution
Tell us what is happening on site, what you need to see, and the event you need to hear about. We will come back with the system that answers it.
Direct contact
Location
Venator House, Unit 9, 15-17 St Stephen's Road, Bournemouth
Dorset, BH2 6LA · VAT GB 409644484
Products contact
Contact the engineering team
Direct to the team that designs and builds the range. Tell us the equipment and the event that matters.