In-Kiln Moisture Meter System for Batch Kilns
Shut down your kiln at the right time. Every time.
AccuStop™ measures the true moisture content of lumber inside the kiln with 1% endpoint accuracy.
Trusted in more than 75 kilns across Eastern Canada, AccuStop™ automatically advances drying schedules, eliminates hot checks, reduces overdrying and lessens moisture variation.
AccuStop™
Developed by SECOVAC and launched in 2013, the AccuStop™ system was one of the first in-kiln moisture measurement plate systems.
AccuStop™ measures the moisture content of a large sample of lumber at various locations in the dry kiln during the drying process. It measures moisture content above and below fiber saturation point, in real-time, within 1% endpoint accuracy, enabling the development of more efficient and effective drying schedules.
Eliminates the need for hot checks at the end of each load
Automatically shuts down the kiln based on actual moisture content within 1% of the target humidity
Reduces drying times through optimized schedules
Lowers energy consumption by eliminating unnecessary kiln hours
Improves grade yield by avoiding over- and under-drying
Enables automated kiln control based on real lumber moisture content
How It Works
AccuStop is a plate system based on capacitance. Two (2) stainless steel plates are inserted into a stack of lumber inside the batch kiln, extending the full width of the pack. This makes up one sample which typically contains 200-350 boards. Depending on kiln length and layout, 4 to 8 samples are installed per kiln.
1 / A time-harmonic electromagnetic field is generated and sent between each of the two (2) plates. A meter located outside the kiln measures the field, or capacitance, between the two (2) plates.
2 / The reading is converted in the controller into the real moisture content of the lumber. The MC is displayed both numerically and graphically on the AccuStop LCD screen, and is sent to the PLC.
3 / Before pushing the charge out of the kiln, cables are disconnected and plates are removed for reuse in the next green charge.
When the AccuStop data is integrated into the kiln control system, operators can:
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Run moisture-driven drying schedules
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Automatically advance schedule segments
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Shut down the kiln precisely at target moisture content
Stainless plates inserted into the stack with spring clips attached to them.
Lumber MC over drying time
System Features
Measures the full moisture range, above and below the fiber saturation point, with 1% endpoint accuracy
Continuously monitors the drying process with real-time feedback
Measures moisture content of a large representative samples, typically 250 to 350 boards per stack
Delivers consistent, repeatable shutdown results
Integrates with most computerized kiln controller
FAQ
Does AccuStop replace hot checks?
Yes. Accustop provides continuous, in-kiln moisture measurement. Our clients typically routine hot checks after installation.
Why does it matter that AccuStop can measure the moisture content above and below fiber saturation point (FSP)?
Fiber saturation point (FSP) is the transition between free water and bound water removal. Many systems lose accuracy near this critical stage. AccuStop measures moisture content accurately on both sides of FSP, allowing operators to develop more efficient schedules, particularly for MSR or dense lumber.
Once the lumber reaches FSP, it can tolerate a more aggressive drying schedule, which in turn reduces overall drying time. However, if this transition is made too early, the surface of the lumber can caseharden. The moisture gradient between the shell and the core increases, leading to internal stresses, defects and longer drying times.
AccuStop eliminates the guesswork at this critical stage. With accurate data through the FSP transition, operators can push drying safely, improving efficiency, quality, and consistency without increasing risk.
Why is it critical to stop the kiln at the right time?
Overdrying directly reduces lumber value. A study by Peter Garrahan (Forintek) established that final moisture content is the most significant factor affecting value loss due to drying. Stopping within 1% of target moisture improves grade yield, reduces energy costs, and protects profitability.