Illuminance and smart lighting
The SimtoLink light sensor is built around a silicon photodiode. For human vision and architectural lighting it reports illuminance (lux), with a typical range of 0～65535 lux. Spectral response sits close to the CIE photopic curve. For agriculture and plant factories, photosynthetically active radiation (PAR) is an option, and PPFD (μmol·m⁻²·s⁻¹) states supplemental-light intensity. Lux and PPFD are chosen side by side and calibrated apart.
Cosine correction cuts the effect of the angle of incidence. Outputs are Modbus, 4～20 mA, and 0～10 V, and the sensor can work with a DALI (Digital Addressable Lighting Interface) lighting system and a BMS. It is already used in offices, schools, hospitals, and plant factories. With a smart lighting system, energy use can fall 30%～50%, and the space is easier on the eyes.
Parameters and outputs
Several builds differ by range and by output, so the sensor can cover different illuminance jobs. The table is a typical reference:
| Application | Typical range | Typical use |
|---|---|---|
| Indoor | 0～2000 Lux | Office buildings, classrooms, hospitals |
| Outdoor | 0～100k Lux | Road lighting, outdoor illuminance |
| Greenhouse or plant factory | Lux, or a PPFD/PAR build | Supplemental-light control, photoperiod, DLI |
| Output | Modbus / 4～20 mA / 0～10 V | DALI gateway and BMS |
The eye-response build matches visible light to the CIE curve. The PAR/PPFD build is calibrated to quantum flux, over a typical band of about 400～700 nm, depending on the detector. Response time is under 1 s. Supply is DC 12～24 V. The allowed ambient range is −30℃～70℃. Outdoor models can reach IP65, depending on the enclosure. The Modbus version can be daisy-chained, up to 32 units on one bus. A hood is optional. These are typical values for the standard models. The product specification decides.
Typical deployments and what they delivered
The same sensor covers on-demand dimming in an office, supplemental light in a plant factory, and street lighting. These are the jobs and the results:
DALI dimming in an office
One office building installed 80 light sensors and tied them to a DALI lighting system. Lights dim to the need of the room, energy use fell 35%, and the space is easier on the eyes.
Supplemental light in a plant factory
One plant factory switches supplemental lights, and sets their intensity, from the light reading. Crop yield rose 20%, and photoperiod and intensity stay inside the recipe.
Street-light dimming
One city lighting project put sensors on 50 road sections and sets lamp brightness from daylight. Energy use fell 25%, and the lamps last longer.
Classroom lighting that is easier on the eyes
Classrooms use the sensor to follow daylight and artificial light, holding a constant illuminance and meeting eye-comfort lighting standards.
Selection and installation
- Range: Indoors, use 0～2000 lux. Outdoors, use 0～100k lux. Where shading is required, choose a model with a hood.
- Interface: For a BMS, choose Modbus. For lighting control alone, 0～10 V or DALI is enough.
- Location: Mount the sensor in a representative spot. Keep it out of a local shadow and out of a hard beam, or the reading drifts. Mounting height should match the work plane.
- Dimming policy: Tune the policy to the building, how people use it, and how daylight moves, so the lights do not hunt. Set a floor illuminance.
- Help with the job: SimtoLink can design the lighting-control logic and tune the policy, so energy and comfort stay in balance.
How the job is run, and how it is kept
Move a light-sensor and lighting-interlock job in this order, against the illuminance or supplemental-light target:
SimtoLink can design the lighting and supplemental-light policy, and can review energy use and the crop light environment.
Support
SimtoLink selects the light sensor and designs the lighting-control policy, including a tie-in to DALI, a BMS, and similar systems, and can review the energy result and suggest changes. A product manual and a proposal quote are available.