Abstract: An apparatus for measuring flow in a conduit includes a sensor head configured for insertion transversely through a conduit sidewall to position the sensor head in an electrically conductive fluid flowing through the conduit. The sensor head includes a core and a coil that at least partially surrounds the core, the coil being excitable to generate an electromagnetic field. The sensor head also includes first and second electrodes spaced apart from each other, and a body that supports the coil, core, and electrodes. The body includes at least one channel through which the electrically conductive fluid flows. The electrodes are positioned in the at least one channel. Each channel is defined by opposing sidewalls that have a converging configuration.

Abstract: An apparatus for measuring flow in a conduit includes a sensor head configured for insertion transversely through a conduit sidewall to position the sensor head in an electrically conductive fluid flowing through the conduit. The sensor head includes a core and a coil that at least partially surrounds the core, the coil being excitable to generate an electromagnetic field. The sensor head also includes first and second electrodes spaced apart from each other, and a body that supports the coil, core, and electrodes. The body includes at least one channel through which the electrically conductive fluid flows. The electrodes are positioned in the at least one channel. Each channel is defined by opposing sidewalls that have a converging configuration.

Abstract: A method and apparatus for balancing terminals of an HVAC system uses an air flow measuring device by inputting into a computer processing portion of the air flow measuring device predetermined target flows for each terminal; acquiring via the air flow measuring device initially measured air flows through each of the terminals, the initially measured air flows being provided to the computer processing portion; and adjusting the terminals in the HVAC system to flow set points according to instructions from the computer processing portion, the computer processing portion being programmed to calculate the flow set point for each terminal given current HVAC system load conditions, that will result in all terminals being set to target flow after all terminals have been adjusted as instructed.

Abstract: An apparatus for obtaining pressure measurements in an airstream includes a Pitot tube. The Pitot tube includes at least one total pressure port configured to be positioned in the airstream facing upstream, at least one static pressure port configured to be positioned in the airstream facing downstream, at least one first directional port, and at least one second directional port. The at least one first directional port and the at least one second directional port are positioned on opposite sides of the at least one total pressure port and face obliquely with respect to the direction that the at least one total pressure port faces.

Abstract: A rotameter includes a rotameter body including an inlet, an outlet, and a flow channel that provides fluid communication between the inlet and the outlet. A valve for controlling fluid flow through the inlet includes an actuator rotatable about a first axis. The actuator includes worm gear threads. The valve also includes a valve drive element rotatable about a second axis that extends transverse to the first axis. The valve drive element includes worm gear teeth that mate with the worm gear threads on the actuator so that rotation of the actuator about the first axis imparts rotation of the valve drive element about the second axis. The valve drive element further includes first screw threads that rotate with the valve drive element about the second axis. The first screw threads are configured and arranged to mate with and engage second screw threads to cause linear movement of a valve component along the second axis in response to rotation of the valve drive element.

Abstract: A humidity sensor arrangement for providing temperature compensated measurements. A first sensor is configured internal to a housing for the sensor arrangement, and a second sensor is configured external to the housing. The first sensor measures a first relative humidity at a first temperature, and the second sensor measures second temperature external. A processor determines saturation pressures for the first and second sensors and compensates the first sensor by adjusting the relative humidity for the first sensor to be a product of the relative humidity for the first sensor and a ratio of the saturation pressure of the first and second sensors. Further compensation may be produced by applying a time-based filter algorithm to the outputs of the first and second sensors. Temperature sensors can be compensated to determine room temperature and compensated temp can be used for precise humidity compensation.

Abstract: An apparatus for obtaining pressure measurements in an airstream includes a Pitot tube. The Pitot tube includes at least one total pressure port configured to be positioned in the airstream facing upstream, at least one static pressure port configured to be positioned in the airstream facing downstream, at least one first directional port, and at least one second directional port. The at least one first directional port and the at least one second directional port are positioned on opposite sides of the at least one total pressure port and face obliquely with respect to the direction that the at least one total pressure port faces.

Abstract: An apparatus for measuring airflow through a diffuser of an HVAC system includes a hood for being positioned adjacent the diffuser so that airflow discharged from the diffuser is directed into the hood. The hood is configured to divide and direct the airflow through a plurality of discharge channels. Sensor probes measure the airflow through each discharge channel.

Abstract: An apparatus for measuring airflow through a diffuser of an HVAC system includes a hood for being positioned adjacent the diffuser so that airflow discharged from the diffuser is directed into the hood. The hood is configured to divide and direct the airflow through a plurality of discharge channels. Sensor probes measure the airflow through each discharge channel.

Abstract: A method and apparatus for balancing terminals of an HVAC system uses an air flow measuring device by inputting into a computer processing portion of the air flow measuring device predetermined target flows for each terminal; acquiring via the air flow measuring device initially measured air flows through each of the terminals, the initially measured air flows being provided to the computer processing portion; and adjusting the terminals in the HVAC system to flow set points according to instructions from the computer processing portion, the computer processing portion being programmed to calculate the flow set point for each terminal given current HVAC system load conditions, that will result in all terminals being set to target flow after all terminals have been adjusted as instructed.

Abstract: A pressure transducer for a hammer union installation includes a lower body capable of withstanding the stresses of the hammer union installation. The lower body includes a cylindrical wall, a diaphragm, and a pressure port for exposing the diaphragm to pressure. The pressure transducer also includes one or more transducer elements mounted on the diaphragm that are operable to provide a signal related to pressure. A cap is received by the cylindrical wall and is slidable along the wall. The cap includes comprising an antenna for transmitting the signal. A spring is arranged in the lower body for dampening forces applied to the cap.

Abstract: An apparatus for measuring airflow through a diffuser of an HVAC system includes a hood for being positioned adjacent the diffuser so that airflow discharged from the diffuser is directed into the hood. The hood is configured to divide and direct the airflow through a plurality of discharge channels. Sensor probes measure the airflow through each discharge channel.

Abstract: A rotameter includes a rotameter body including an inlet, an outlet, and a flow channel that provides fluid communication between the inlet and the outlet. A valve for controlling fluid flow through the inlet includes an actuator rotatable about a first axis. The actuator includes worm gear threads. The valve also includes a valve drive element rotatable about a second axis that extends transverse to the first axis. The valve drive element includes worm gear teeth that mate with the worm gear threads on the actuator so that rotation of the actuator about the first axis imparts rotation of the valve drive element about the second axis. The valve drive element further includes first screw threads that rotate with the valve drive element about the second axis. The first screw threads are configured and arranged to mate with and engage second screw threads to cause linear movement of a valve component along the second axis in response to rotation of the valve drive element.

Abstract: A humidity sensor arrangement for providing temperature compensated measurements. A first sensor is configured internal to a housing for the sensor arrangement, and a second sensor is configured external to the housing. The first sensor measures a first relative humidity at a first temperature, and the second sensor measures second temperature external. A processor determines saturation pressures for the first and second sensors and compensates the first sensor by adjusting the relative humidity for the first sensor to be a product of the relative humidity for the first sensor and a ratio of the saturation pressure of the first and second sensors. Further compensation may be produced by applying a time-based filter algorithm to the outputs of the first and second sensors. Temperature sensors can be compensated to determine room temperature and compensated temp can be used for precise humidity compensation.

Abstract: A pressure transducer for a hammer union installation includes a lower body capable of withstanding the stresses of the hammer union installation. The lower body includes a cylindrical wall, a diaphragm, and a pressure port for exposing the diaphragm to pressure. The pressure transducer also includes one or more transducer elements mounted on the diaphragm that are operable to provide a signal related to pressure. A cap is received by the cylindrical wall and is slidable along the wall. The cap includes comprising an antenna for transmitting the signal. A spring is arranged in the lower body for dampening forces applied to the cap.