1.25" (3.17cm) Digital Flow Meter

What the DFM-2 Is

The TrolMaster DFM-2 is a 1.25-inch digital inline flow meter purpose-built for integration with the TrolMaster Aqua-X Pro irrigation control system (NFS-2). It installs directly into an irrigation mainline and measures the real-time volumetric flow of water or nutrient solution passing through the pipe. An onboard LCD provides on-site readout so technicians can verify flow without pulling up the controller interface.

The DFM-2 is the mid-size option in TrolMaster's DFM flow meter lineup, which also includes the 1" DFM-1 and the 1.5" DFM-3 — allowing operators to match meter bore size to their existing mainline diameter without reducing flow or adding unnecessary restrictions. The DFM-2 ships with NPT tapered thread adaptors for straightforward inline installation.

Feed by Volume: Why It Matters for Commercial Cultivation

Time-based irrigation is a blunt instrument. Pump pressure varies, emitters clog, and a fixed-duration event delivers different actual volumes run to run. When paired with the Aqua-X Pro (NFS-2) controller, the DFM-2 shifts the trigger model entirely: irrigation events are governed by a target volume of solution delivered, not by a clock. The controller reads the DFM-2 signal in real time and closes valves or stops pumps once the programmed volume threshold is reached.

For crop-steering protocols, this is a meaningful operational improvement. Precise shot volumes — whether 100 mL per dripper event in an early generative phase or larger saturation events at lights-on — are repeatable batch to batch, zone to zone, and day to day. Variance from pump wear or line pressure fluctuation gets corrected automatically by the volume gate rather than accumulating as untracked error across a crop.

Key Features

LCD display with on-site monitoring: technicians can read current flow rate directly at the meter without accessing a controller panel or app. Real-time measurement ensures immediate visibility into line performance during zone checks or troubleshooting.

Feed by Volume function: when wired to the Aqua-X Pro main controller, the DFM-2 enables volume-controlled irrigation scheduling — a core feature for precise nutrient delivery in commercial cannabis and hemp production.

Forward-compatible sensor architecture: TrolMaster has designed the DFM-2 sensor for potential future firmware functions, including water leak detection and line blockage identification. Facilities investing in the Aqua-X Pro ecosystem benefit from this expandability without hardware replacement.

Sized for medium-bore mainlines: the 1.25" bore suits facilities running larger flow volumes than a 1" line supports but not yet at the 1.5" scale of the DFM-3. Selecting the correct bore minimizes pressure drop and keeps flow measurement accurate across the sensor's rated range.

How It Fits a Commercial Build

The DFM-2 is an accessory component within the TrolMaster Aqua-X Pro ecosystem — it does not operate as a standalone controller. The NFS-2 main controller is required to enable the Feed by Volume function and to receive sensor data for irrigation event logic. The DFM-2 connects to the NFS-2 and requires power via the SPH-1 hub. Connection is made via standard RJ12 cable, consistent with TrolMaster's daisy-chain wiring architecture used across their sensor and module lineup.

For multi-zone commercial facilities, the Aqua-X Pro NFS-2 can manage up to 30 irrigation zones and monitor up to 50 sensors simultaneously — making the DFM-2 a natural fit in builds where pH, EC, water temperature, and medium moisture sensors are already deployed on the same backbone. Operators running volume-based crop-steering programs across multiple rooms can deploy one DFM per mainline zone, each reporting independently to the NFS-2 while sharing a unified controller interface.