Growlink SDI-12 Climate Sensor Built for PIC and Connect Controllers
The ESM-3 reports air temperature, humidity, VPD, photocell, and optional CO2 through one SDI-12 digital interface. Each SDI-12 input on a Precision Irrigation Controller supports one ESM-3 plus one substrate probe. A standalone PIC handles four climate sensors and four substrate probes at once. Temperature reads -40 to 60°C with ±0.5°C accuracy. Humidity tracks 0-100% RH non-condensing with ±3% accuracy between 20-80% RH at 25°C.
Eco Climate Sensor With Onboard Compensation and Low Power Draw
Optional CO2 measurement runs 0-5000 ppm with ±50 ppm + 2-3% accuracy. Onboard temperature and pressure compensation keeps the readings honest as the room swings through veg, bloom, and lights-out cycles. The sensor draws low current on +12VDC, so a single SDI-12 input on a PIC supplies both power and data with three conductors. Multiple ESM-3 readings can be averaged in the controller or kept separate for zone-by-zone canopy climate mapping.
Key Features
- SDI-12 Digital Output: One three-conductor cable carries +12VDC, signal, and ground from the controller to the sensor body.
- Air T, RH, VPD, Photocell: Standard climate readings derived from the sensor's onboard array, with VPD computed on the controller side.
- Optional CO2 Channel: Adds 0-5000 ppm CO2 measurement with ±50 ppm + 2-3% of measured value accuracy.
- PIC and Connect Compatible: Wires to any Growlink SDI-12 input or any third-party SDI-12 data logger that follows the spec.
- Onboard Compensation: Temperature and pressure compensation keeps the CO2 and humidity readings stable across day and night swings.
Technical Specifications
| Specification | Value |
|---|---|
| Measurements | Air temperature, humidity, VPD, photocell, optional CO2 |
| Communication | SDI-12 digital |
| Power | +12VDC (supplied through SDI-12 input) |
| Temperature Range | -40 to 60°C (-40 to 140°F) |
| Temperature Accuracy | ±0.5°C (±0.9°F at 5-60°C) |
| Humidity Range | 0 - 100% RH (non-condensing) |
| Humidity Accuracy | ±3% RH at 25°C, 20-80% RH |
| CO2 Range (Optional) | 0 - 5000 ppm |
| CO2 Accuracy | ±50 ppm + 2-3% of measured value |
| Compensation | Onboard temperature + pressure compensation |
| Wire Configuration | Brown +12VDC / White signal / Blue ground (or equivalent color code) |
| Compatible Controllers | Precision Irrigation Controller (PIC), Connect Controller, any SDI-12 data logger |
| Multi-Sensor Use | Up to 4 ESM-3 per PIC, with averaging or per-sensor readings |