Abstract: Sensor accuracy issues may arise when a humidity sensor is kept in a high humidity environment for an extended period of time. In these circumstances, a humidity sensor reading may tend to may become less accurate over time. To improve the accuracy of sensor readings, methods and systems described herein estimate and correct for sensor drift in high humidity conditions. Methods and systems described herein may use memory to store past humidity or other sensor readings so that an estimated amount of sensor drift may be determined to improve the accuracy of sensor readings. A memory may be embedded in a sensor module so that past readings for a given sensor module are stored in the memory of the sensor module. Algorithms for sensor drift compensation, and systems and methods that use such algorithms to improve the accuracy of sensor readings, are disclosed herein.

Abstract: Methods and apparatus are disclosed for automated acquisition of moisture readings using a handheld moisture meter. In automated mode, a succession of moisture content readings at successive positions can be acquired without any user interface input, by moving the moisture meter to successive positions on a sample, and holding steady at each position. Moisture readings stable for a time period (e.g. one second) are indicative of moisture content of a sample at a stationary position and are collected. Moisture readings varying in time are indicative of motion of the moisture meter and are not collected. Statistics can be performed on the collected readings. Notifications of stable readings and alerts for out-of-range readings can be provided. Hardware and software architectures are disclosed. The innovative technology is suitable for wood, concrete, and other materials at any stage of manufacturing or product lifecycle.

Abstract: Methods and apparatus are disclosed for calibration determinations for handheld moisture meters in the field. A calibration reference stand emulates a sample with an equivalent moisture content, allowing rapid determination whether a moisture meter is out of calibration, or determination of a new calibration value. The calibration reference stand includes an electromagnetic load, which can be formed of a metal sheet or high dielectric constant material, supported on a platform, and mechanical fixturing for reproducible positioning of a moisture meter on the stand. Associated methods and variations are disclosed.

Abstract: Sensor accuracy issues may arise when a humidity sensor is kept in a high humidity environment for an extended period of time. In these circumstances, a humidity sensor reading may tend to may become less accurate over time. To improve the accuracy of sensor readings, methods and systems described herein estimate and correct for sensor drift in high humidity conditions. Methods and systems described herein may use memory to store past humidity or other sensor readings so that an estimated amount of sensor drift may be determined to improve the accuracy of sensor readings. A memory may be embedded in a sensor module so that past readings for a given sensor module are stored in the memory of the sensor module. Algorithms for sensor drift compensation, and systems and methods that use such algorithms to improve the accuracy of sensor readings, are disclosed herein.

Abstract: Methods and apparatus are disclosed for automated acquisition of moisture readings using a handheld moisture meter. In automated mode, a succession of moisture content readings at successive positions can be acquired without any user interface input, by moving the moisture meter to successive positions on a sample, and holding steady at each position. Moisture readings stable for a time period (e.g. one second) are indicative of moisture content of a sample at a stationary position and are collected. Moisture readings varying in time are indicative of motion of the moisture meter and are not collected. Statistics can be performed on the collected readings. Notifications of stable readings and alerts for out-of-range readings can be provided. Hardware and software architectures are disclosed. The innovative technology is suitable for wood, concrete, and other materials at any stage of manufacturing or product lifecycle.

Abstract: Methods and apparatus are disclosed for calibration determinations for handheld moisture meters in the field. A calibration reference stand emulates a sample with an equivalent moisture content, allowing rapid determination whether a moisture meter is out of calibration, or determination of a new calibration value. The calibration reference stand includes an electromagnetic load, which can be formed of a metal sheet or high dielectric constant material, supported on a platform, and mechanical fixturing for reproducible positioning of a moisture meter on the stand. Associated methods and variations are disclosed.

Abstract: Disclosed RH generators include a lower component having a first chamber and an upper component including a second chamber, the upper component being coupled to the lower component to couple the first chamber to the second chamber. The first chamber is configured to contain liquid water and generate 100% RH, while the second chamber is configured to contain salt and generate a second RH less than 100% RH. A first membrane is positioned between the first chamber and the second chamber to allow water vapor to pass between the first and second chambers while blocking liquid water, the salt, and other larger molecules. The upper component is couplable to an RH probe with a second membrane separating the second chamber from the RH probe, which allows water vapor to pass between the second chamber and the RH probe to expose the RH probe to the second RH.

Abstract: Disclosed RH generators include a lower component having a first chamber and an upper component including a second chamber, the upper component being coupled to the lower component to couple the first chamber to the second chamber. The first chamber is configured to contain liquid water and generate 100% RH, while the second chamber is configured to contain salt and generate a second RH less than 100% RH. A first membrane is positioned between the first chamber and the second chamber to allow water vapor to pass between the first and second chambers while blocking liquid water, the salt, and other larger molecules. The upper component is couplable to an RH probe with a second membrane separating the second chamber from the RH probe, which allows water vapor to pass between the second chamber and the RH probe to expose the RH probe to the second RH.

Abstract: A system and method is disclosed that uses moisture content readings in order to determine how to maximize the price value of lumber. Feedback can then be provided to a kiln controller on how to adjust kiln settings in order to increase the value of the lumber produced. In one embodiment, moisture content is determined on a plurality of boards. Using the moisture content readings, an actual value of the plurality of boards is determined. Then a calculation is made to determine how to modify moisture content in order to maximize the value of the lumber. In yet another embodiment, geographic positions of individual packages are tracked in the kiln. The efficiency of the kiln is determined based on drying uniformity of the packages. Then the moisture content can be modified to determine how it impacts value of a charge of lumber.

Abstract: The method utilizes a known good set of moisture content data for wood dried in a kiln under set conditions to estimate parameters for a Lognormal distribution which approximates the moisture content data for those conditions. The method creates control charts which monitor some of these parameters. The method also takes data from subsequent kiln charges and transforms it to be represented on the control charts. The method uses this representation to determine if the kiln is operating under out-of-control conditions.

Abstract: A plate array for moisture sensors has a transmitter electrode and a detector electrode interposed between portions of a phase electrode. The transmitter and phase electrodes are driven with alternating current signals having a one hundred and eighty degree phase difference so as to induce a signal at the detector electrode relating to a moisture content of a material in the electrical fields which has a reduced sensitivity to electrically loading the material, such as from contact with a hand or steel roller.

Abstract: A meter for measuring the moisture content of wood in the center of a stack of wood has a probe with an electromagnetic wave sensor mounted near a forward end and a meter mounted at an opposite end. An extendable member is also mounted at the forward end of the probe. The extendable member is pivoted by a slide handle at the opposite end of the probe between reclined and extended positions. The forward end of the probe is inserted into a stack of wood between layers of the stack. The extendable member is extended to press the sensor against wood in the center of the stack. The meter then registers the moisture content of the wood.

Abstract: A detector circuit in a moisture detector having an oscillator, a detector electrode and a common electrode for measuring the moisture content of wood and structural materials in buildings comprises a clamping diode network which couples an AC signal generated in the oscillator to a detector electrode. The clamping network clamps the AC signal to a reference voltage. The clamping network is balanced by a second clamping diode network which, together with a low pass filter, establishes the reference voltage. A low pass filter connected to the first clamping network produces an output voltage signal related to the impedance between the electrodes. To maintain the circuit's stability, the diodes in the clamping networks are thermally coupled.

Abstract: A meter for measuring the moisture content of wood in the center of a stack of wood has a probe with an electromagnetic wave sensor mounted near a forward end and a meter mounted at an opposite end. An extendable member is also mounted at the forward end of the probe. The extendable member is pivoted by a slide handle at the opposite end of the probe between reclined and extended positions. The forward end of the probe is inserted into a stack of wood between layers of the stack. The extendable member is extended to press the sensor against wood in the center of the stack. The meter then registers the moisture content of the wood.

Abstract: A kiln controller controls the drying of lumber in a kiln by executing a drying schedule and adjusting the drying schedule in response to actual measured conditions in the kiln. A computer within the controller controls heating coils, spray nozzles and vents in the kiln to achieve the conditions prescribed in the drying schedule. The computer first executes a routine whereby the kiln temperature is brought up to a desired initial temperature. Then the computer concurrently executes the drying schedule and a routine wherein it monitors the temperature, vent load and spray nozzle activity, and automatically adjusts the duration of the current step in the drying schedule.

Abstract: Moisture in wood veneer strips received from a drying oven is measured by passing a first radio frequency signal through the veneer for reception by a receiving plate, transmitting a second radio frequency signal in out-of-phase relation to the first radio frequency signal for reception by the receiving plate, the second signal not passing through the wood. The first and second radio frequency signals induce a potential in the receiving plate, the induction of the first radio frequency signal varying in accordance with the moisture contained in the veneer. The potential of the receiving plate is then measured to determine the extent of moisture in the veneer.