Hydronix Moisture Sensing

Aggregate moisture varies — batch to batch, bin to bin, and season to season. Sand that arrives at 6am on a wet day carries significantly more free water than the same sand at 2pm after it has drained. When that moisture variation goes uncompensated, the water added to the mix is wrong before the drum starts turning. The batch controller knows the target water-cement ratio for every mix design, but it can only hit that target if it knows how much water the aggregates are already carrying.

Uncompensated moisture means slump variation at the discharge end — batches running too wet or too dry, drivers calling back from site with workability complaints, and plant operators adjusting water manually to compensate for something the control system should be handling automatically. Over time it also means concrete strength variability: a batch that lands 5% wetter than target has a materially different water-cement ratio, which affects 28-day compressive strength results and puts QA compliance at risk.

Hydronix sensors solve this by giving the Archer batch controller a real-time moisture reading from aggregate bins, conveyor belts, and inside the mixer itself. Archer uses that reading to automatically subtract the free water contribution from the aggregate before calculating how much water to add. When the integration is done correctly — sensor in the right position, calibrated to the actual material, with RS485 output wired into the Archer moisture input — the batch controller compensates automatically for every load. That is what APE delivers as an integrator.

Ordering sensors from a distributor and having them installed by a general electrician produces a different result than what APE delivers. The difference is not the hardware — it is everything that happens around the hardware.

Sensor selection is the first decision point. A Hydro-Probe in a bin neck under an aggregate gate reads differently to a Hydro-Mix flush-mounted in a concrete mixer. Matching the right sensor to the installation point — and positioning it where the material flow is representative of what the batch controller needs to know — requires understanding the batching process, not just the sensor specifications.

Calibration is where most non-specialist installations fall short. Hydronix sensors use microwave moisture measurement — the dielectric response varies with material type, density, and aggregate source. A calibration curve built for crusher dust from one quarry will read incorrectly when aggregate supply changes. APE performs material-specific calibration using Hydro-Com software for each aggregate type on the plant, with documented calibration points that can be revisited when source material changes.

The integration with Archer is where the moisture reading becomes useful. Wiring the RS485 output from a Hydronix sensor into the batch controller so that Archer's moisture compensation is actually active — and configured correctly for each mix design — is the step that converts a sensor from a display number into an automated water correction. APE commissions both sides of that interface: the sensor settings and the Archer moisture input configuration together.

After commissioning, aggregate moisture characteristics change seasonally — particularly in sand stockpiles exposed to weather. Calibration curves that were accurate in summer may read 1-2% high in winter after extended rainfall. APE includes calibration drift review as part of ongoing plant support, checking sensor readings against oven-dry moisture tests during scheduled service visits and updating calibration curves when deviation is detected. This is the ongoing management that ensures moisture compensation keeps working — not just on commissioning day.