Closed-loop PPFD control for Hydro-X, Hydro-X Plus, and Hydro-X Pro systems.
The TrolMaster MBS-PAR Full Spectrum Quantum Sensor measures photosynthetically active radiation (PAR) across a 389–692 nm spectral range and feeds real-time PPFD data directly to a Hydro-X series controller — enabling automatic, closed-loop dimming of supplemental lighting systems to hold a precise canopy light target.
The MBS-PAR is a dedicated quantum sensor that measures photosynthetically active radiation in micromoles per square meter per second — the PPFD unit growers actually use to dial in canopy light targets. It connects to any Hydro-X series controller (Hydro-X, Hydro-X Plus, Hydro-X Pro) over a standard RJ12 cable and delivers a live PPFD reading to the controller continuously.
Unlike a simple photocell or lux meter, the MBS-PAR reads across a full 389–692 nm window — slightly wider than the conventional 400–700 nm PAR definition — and its improved spectral response makes it accurate across LED, HPS, CMH, and mixed-source lighting environments. The output is a true PPFD number, not a relative lux value, so the controller can work in the same units the grower's target recipe specifies.
A schedule-based dim percentage delivers a fixed driver command, not a fixed amount of light hitting the canopy. Drivers drift. Lamps depreciate over time. Reflective surfaces lose efficiency across a long flower run. The result is that a fixture set to a fixed dim level delivers measurably less PPFD in week 10 than it did in week 1 — with no corrective action from the controller.
When the MBS-PAR is in the loop, the Hydro-X controller compares actual measured PPFD against the operator-programmed target and automatically increases or decreases fixture output to close the gap. For commercial operators running tight light recipes across multiple zones or back-to-back crops, this is the difference between a repeatable environment and one that slowly drifts between harvests. The Hydro-X Plus also uses MBS-PAR data to track Daily Light Integral (DLI) — a useful metric for dialing in photoperiod and intensity simultaneously.
Any licensed cannabis or hemp operator running a TrolMaster Hydro-X series controller who wants to move from schedule-based lighting to verified, canopy-level PPFD control. This applies equally to LED-dominant rooms — where the MBS-PAR's improved spectral response provides accuracy that a basic lux photocell cannot — and to facilities running double-ended HPS, CMH, or hybrid multi-source configurations.
The MBS-PAR is also the right add-on for operators who already have an MBS-PRO 4-in-1 sensor covering temperature, humidity, CO2, and presence-of-light, but want to upgrade the lighting channel from a simple day/night photocell to a calibrated, closed-loop PPFD measurement. It integrates into the existing RJ12 sensor bus without replacing any other sensor on the chain.
The MBS-PAR ships with a 4 ft RJ12 cable, a ½-inch post clamp for mounting at canopy height, an RJ12 T-splitter for daisy-chaining into an existing sensor bus, and two ½-inch end caps. Mounting at canopy level and pointing the sensor element upward toward the fixture plane is the standard setup. The post clamp accommodates ½-inch vertical supports common in vertical rack builds and trellis systems.
Each Hydro-X, Hydro-X Plus, and Hydro-X Pro controller supports one MBS-PAR PAR sensor per zone. Sensors and control modules daisy-chain via RJ12 T-splitters, so adding the MBS-PAR to an existing installation does not require rewiring — it drops into the chain at any convenient point. Keep the sensor element dry and free of condensate or spray residue; contamination on the sensor surface affects reading accuracy over time. Operating humidity ceiling is 90% non-condensing.
| SKU | MBS-PAR |
| Manufacturer | TrolMaster |
| Sensor Type | Full Spectrum Quantum (PPFD) |
| Spectral Range | 389–692 nm ± 5 nm |
| Output Unit | µmol/m²/s (PPFD) |
| Connector | RJ12 (standard 6-pin) |
| Compatible Controllers | Hydro-X (HCS-1), Hydro-X Plus (HCS-3), Hydro-X Pro (HCS-2) |
| Working Temperature | 32–122°F (0–50°C) |
| Working Humidity | ≤ 90% RH (non-condensing) |
| Package Dimensions | 160 mm (L) × 86 mm (W) × 86 mm (H) |
| In the Box | 1× Quantum Sensor, 1× ½" Post Clamp, 1× 4 ft RJ12 Cable, 1× RJ12 T-Splitter, 2× ½" End Cap |
Yes. The MBS-PAR is compatible with the Hydro-X (HCS-1), Hydro-X Plus (HCS-3), and Hydro-X Pro (HCS-2). Each controller supports one PAR sensor per zone. It connects via the same RJ12 bus used by all other TrolMaster sensors and device stations.
The MBS-PAR's 389–692 nm spectral range and improved spectral response are specifically designed to provide accurate PPFD readings across all light source types, including broad-spectrum LEDs, double-ended HPS, CMH, and mixed-source configurations. The wider spectral window compared to a standard 400–700 nm sensor improves measurement fidelity under modern LED spectra.
The MBS-PRO includes a photocell that detects day/night light presence, but it does not output a calibrated PPFD value in µmol/m²/s. If you want the Hydro-X controller to dim fixtures automatically against a precise canopy PPFD target — rather than a fixed dim percentage or schedule — you need the MBS-PAR added to the sensor bus. The two sensors coexist on the same RJ12 chain without conflict.
Standard practice is to mount the sensor at canopy height, pointing upward toward the fixture plane, using the included ½-inch post clamp. This positions the sensor element where the PPFD target actually matters — at the plant canopy — rather than at a fixed height from the fixture. For multi-tier vertical growing, mount one sensor per zone at the tier being controlled.
The MBS-PAR is rated for operating temperatures of 32–122°F and humidity up to 90% RH (non-condensing). It is not rated for direct outdoor exposure or condensing environments. TrolMaster recommends keeping the sensor dry and free of spray or condensate to prevent premature failure. For greenhouse applications, verify that the installation location stays within the stated humidity and temperature limits.
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