A new sensing device detects residual moisture levels as low as 10 parts per million (PPM) in polymers in real time. Installed at the outlet of a drying hopper, the Moisture Minder from Conair achieves throughput rates of 20 to 5,000 lb/hr.

The real-time monitor measures material moisture continually; set points can be configured to issue an alert when the specified moisture level drifts outside prescribed limits. All readings are stored for historical trending, allowing managers to recognize when conditions begin to shift in the wrong direction and make dryer-control changes to avoid compromising the entire volume of material inside the drying hopper. These historical records can also be used for process validation, confirming that parts were manufactured under acceptable conditions.

Using the Moisture Minder in conjunction with Conair's Drying Monitor provides the earliest possible indication that drying conditions are not right. Placed vertically in the drying hopper, the Drying Monitor probe measures temperature at multiple levels in the bed of material being dried, detecting anomalies that could result in higher-than-acceptable moisture levels in the resin as it leaves the hopper hours later.

The Moisture Minder also can be retrofitted to existing systems.

Two models are available: The M5 unit detects moisture levels between 10 and 1,000 ppm, while the M10 tracks moisture between 300 and 3,000 ppm. The all-electric sensors have no moving parts to maintain or change. Operation is passive, so there is no impact on production rates. A yearly calibration and cleaning are the only regular maintenance chores, said Conair.

A color touch screen control enables setup and monitoring of up to eight drying hoppers. Users can also communicate with the Moisture Minder or pull data into a plant-supervisory system using ModBus TCP/IP communications or, optionally, with OPC UA protocol.