Abstract: A gas valve assembly includes a gas valve and a control circuit. The gas valve is configured for variably controlling a flow of gas through the gas valve assembly. The control circuit includes a controller programmed to determine a first setting for the gas valve in response to a received commanded flow, adjust the first setting to a second setting based on a measured temperature when the measured temperature is one that may induce changes to the flow of gas through the gas valve assembly, and control the gas valve based on the second setting.

Abstract: For balancing a hydronic network that comprises a plurality of parallel zones with a regulating valve in each zone, individual flow characteristics are determined (S1) for each of the regulating valves, by recording the total flow of fluid measured at different valve positions of a respective regulating valve, while the remaining other regulating valves are set to a closed valve position. Dependent flow characteristics are determined (S2) by recording the total flow of fluid measured at different valve positions of the respective regulating valve, while the remaining other regulating valves are set to an open valve position. Correction factors are determined (S3) for each of the regulating valves, using the individual flow characteristics and the dependent flow characteristics. The hydronic network is balanced (S4) by setting the valve positions of the regulating valves using target flows and the correction factors.

Abstract: A control device controls movement of a valve body of a valve device and estimates a flow rate of the valve device; determines, on the basis of an input target flow rate value and the flow rate estimate, whether or not the flow of an operating fluid in the valve device is in a transient flow state; calculates an opening command on the basis of the target flow rate value and an upstream-downstream pressure difference of the valve device; and controls the movement of the valve body. When the control device determines that the flow is not in the transient flow state, it controls the movement of the valve body on the basis of the opening command, and when the control determines that the flow is in the transient flow state, it controls the movement of the valve body on the basis of the target flow rate value.

Abstract: A manufacturing system includes a processing chamber, an gas supply, and a mass flow control apparatus coupled to the gas supply and the processing chamber. The mass flow control apparatus includes a flow restriction element configured to restrict a flow rate of a gas, a bypass flow element configured to control the flow rate of the gas in parallel to the flow restriction element, and a pressure regulator configured to control a pressure of the gas between the pressure regulator and the flow restriction element and/or a pressure of the gas between the pressure regulator and the flow restriction element. The manufacturing system further includes a controller that is configured to flow gas from the gas supply to the processing chamber via the mass flow control apparatus in view of a first pressure setting. The controller further determines to modify the flow of the gas from a first flow rate associated with the first pressure setting to a second flow rate.

Abstract: A valve includes a valve housing defining at least one first opening and at least one second opening, the valve housing enclosing a valve chamber. An actuator with a positioning element is configured for opening or closing the valve. Also provided are at least one air mass measuring device for measuring an air mass flowing through the valve or at least one measuring wire of an air mass measuring device for measuring an air mass flowing through the valve. A valve arrangement and a seat comfort system are also disclosed.

Abstract: A safety device against leaks of liquid for a liquid-conducting household appliance comprises a valve arrangement that can be electrically switched between a closing position and an opening position, to prevent or enable, respectively, a flow of liquid from a liquid-supply source to the household appliance. The device further comprises:—a first pipe (13) impermeable to liquid, for the flow of liquid,—at least one hydraulic unit (12), having a duct for the liquid (30),—a flow sensor in the at least one hydraulic unit (12). The first pipe (13) is connected in fluid communication with the duct (30) and extends longitudinally at least in part within a second pipe (14) that is impermeable to liquid, in such a way that defined between at least part of the first pipe (13) and of the second pipe (14) is a gap (G) having a proximal end and a distal end. The at least one hydraulic unit (12) has a respective hydraulic body (16) that defines the duct (30).

Abstract: A device which: optically detects the presence of, measures the flow rate of, and identifies the characteristics of venting fugitive gas emissions. Specifically the device provides a spectral analysis of emission gas constituents; selective detection of the presence of venting hydrocarbons; measurement of venting emissions flow rates, the measurement of shut-in and flowing venting system pressures and the venting system temperatures. The flow rates are corrected, relative to the detection of the gas constituents and standard temperature and pressure (STP). These devices are configured to collect such data electronically and transmit via various telemetry systems, to a secure remote data network for reporting, access, evaluation, real-time monitoring and archiving as required.

Abstract: A gas inspection method includes: inputting a signal for opening a secondary valve; measuring, by a secondary pressure gauge, a pressure P on a downstream side of an orifice of a flow rate controller at a time point when a period t elapses from the input of the signal for opening the secondary valve; measuring, by the secondary pressure gauge, a standard deviation ? of the pressure P on the downstream side of the orifice of the flow rate controller at the time point when the period t elapses from the input of the signal for opening the secondary valve; and determining whether or not an open degree of the secondary valve is normal by comparing the pressure P and the standard deviation ? of the pressure P with a threshold value P0 of the pressure and a threshold value ?0 of the standard deviation of the pressure.

Abstract: Various embodiments provide a leaching solution monitoring module comprising a first leaching solution distribution system interface, a flow meter in fluid communication with the first leaching solution distribution system interface, the flow meter in fluid communication a 3-way pressure regulator, and a second leaching solution distribution system interface in fluid communication with the 3-way pressure regulator.

Abstract: To effectively utilize work information acquired by maintenance of an instrument in a plant, an apparatus is provided, which includes an acquisition unit that acquires work information about at least one of a calibration or an adjustment performed on the instrument in a plant; an extraction unit that extracts a plurality of data elements to be included in output information having a predetermined output format from the work information; and a generation unit that generates the output information from the plurality of data elements.

Abstract: Maximum flow setting. A method of limiting flow through a valve (1) comprising: reading a time series of signals from a flow sensor (5a, 5b); producing a time series of flow rates from the time series of signals; producing an averaged series of values; producing a first bounded series of values by replacing values that are below a lower threshold (13) with the lower threshold (13); producing a second bounded series of values by replacing values that exceed an upper threshold (15) with values that equal the upper threshold (15); producing a maximum flow rate by applying a moving maximum filter (17) to the second bounded series; reading a set point signal (9); limiting the set point signal (9) to the maximum flow rate; producing an actuation signal from the limited set point signal; transmitting the actuation signal to an actuator (7).

Abstract: A fluid control system and associated method for pulse delivery of a fluid includes a shutoff valve and a mass flow controller (MFC) upstream of the shutoff valve. The MFC includes a flow channel, a control valve to control flow of fluid in the flow channel, a flow sensor to measure flow rate in the flow channel, and a controller having a valve input from the shutoff valve indicating opening of the shutoff valve. The controller is configured to respond to the valve input to control flow of fluid through the control valve to initiate and terminate a pulse of fluid from the flow channel to the shutoff valve to control a mass of fluid delivered during the pulse of fluid. The valve input can be a pressure signal, and the MFC can include a pressure sensor to sense the pressure signal.

Abstract: A power off delay system and method is configured to delay termination of electrical power to a digital pathology device in a power off condition. If the apparatus includes a UPS, the power off delay system and method delays termination of electrical power when a power switch is turned off and when a catastrophic power failure occurs. During the delay of the termination of electrical power, the digital pathology device is configured to control the scanning stage system and the glass slide conveyor system and the slide rack conveyor system to place each of these systems into a known state and position all glass slides into a known position prior to the termination of electrical power to the digital pathology device. This allows the digital pathology device to resume normal operation upon power up.

Abstract: The claimed method and system develops a useful lifetime profile for a component of a process control device, such as a valve, and uses that lifetime profile to determine a projected remaining lifetime for the device component in operation. The lifetime profile is developed from using real world operational data of similar process control devices, used under substantially the same operating conditions as to be experienced during operation. Profiles may be developed for numerous device components, from which a projected lifetime profile for the entire process control device is developed. Based on the projected remaining lifetime, notification warnings may be sent to remote computers and maintenance scheduling may be automatically achieved.

Abstract: A self-correcting pressure-based mass flow control apparatus includes outlet pressure sensing to enable correction for non-ideal operating conditions. Further the mass flow control apparatus having a fluid pathway, a shutoff valve in the fluid pathway, a reference volume in the fluid pathway, a first pressure measuring sensor in fluid communication with the reference volume, a first temperature measuring sensor providing a temperature signal indicative of the fluid temperature within the reference volume, a proportional valve in the fluid pathway, and a second pressure measuring sensor in fluid communication with the fluid pathway.

Abstract: The flow rate measuring method is performed in a common gas supply system comprising a plurality of gas supply paths each having a first valve, and a gas measuring device formed downstream side of the plurality of gas supply paths, having a pressure sensor, a temperature sensor, and a downstream side second valve.

Abstract: A system for metering a liquid or gaseous medium comprises a pressure control valve and a flow sensor, the pressure control valve and the flow sensor forming a closed control circuit. The required metering quantity can be adjusted by controlling the metering pressure by means of the pressure control valve.

Abstract: A valve for controlling a fluid flow includes a valve body, a shutter component configured to be able to transition from an open position allowing the circulation of fluid, to a closed position preventing the circulation of fluid. The component is characterized in that it includes a fixed conical support integral with the valve body, a conjugate conical flap rotationally movable relative to the fixed support, and fluid passage apertures respectively arranged in the conical flap and in the fixed support, and an actuator of the shutter component adapted to be able to control the position of the shutter component.

Abstract: A zipper manifold for use in wellbore operations includes a trunk line having a first longitudinal axis, an inlet on a first axial end, an outlet on a second axial end, and a first gate valve positioned between the inlet and the outlet, a block tee fluidly connecting the trunk line to a secondary line, the secondary line having a second longitudinal axis parallel to the first longitudinal axis, a second gate valve positioned along the secondary line, and an outlet head at an end of the secondary line.

Abstract: A flow rate control method for raising a flow rate performed in a flow control device having a first control valve, a second control valve downstream of the first control valve, and a pressure sensor for measuring a pressure between the first and the second control valves, comprises a step (a) of determining a pressure remaining downstream of the first control valve in a state of closing the second control valve, and a step (b) of controlling the pressure remaining downstream of the first control valve by adjusting the opening degree of the second control valve based on the output of the pressure sensor to flow the fluid downstream the second control valve at the first flow rate.

Abstract: The present invention makes it possible to easily obtain a compressibility factor that is a characteristic of a fluid, and thereby dramatically improves the accuracy of flow rate measurement by an ROR system or the like. The invention is adapted to include: a chamber having a constant volume; a flow rate controller connected to the chamber so as to make it possible to introduce or lead a fluid into or out of the chamber at a constant flow rate; and an information processor adapted to calculate a compressibility factor depending on the pressure of the fluid on the basis of time changes in pressure inside the chamber when the fluid is introduced into the chamber at the same flow rate as each other through the flow rate controller under two different pressure conditions inside the chamber.

Abstract: A wearable drug delivery device that can deliver a liquid drug stored in a container to a patient or user is provided. A soft needle or cannula can be placed in fluid communication with the liquid drug and can be coupled to a needle insertion component that provides access to the patient. A drive system of the drug delivery device can expel the liquid drug from the container to the patient through the soft needle or cannula. The wearable drug delivery device can include components for preventing backflow and eliminating air within the liquid drug. As a result, the comfort of the patient can be enhanced and correct drug dosages can be provided when using the drug delivery device.

Abstract: In one aspect the present disclosure relates to a monitoring device for attachment to an injection device, the monitoring device comprising: a body (51) having an inside surface (52) for engagement with an outside surface (19) of the injection device (1) and having an outside surface (53) opposite to the inside surface (52), an light transmission area (60) extending from the inside surface (52) to the outside surface (53), the light transmission area (60) having an inner end (62) adjacent to the inside surface and having an outer end (63) adjacent to the outside surface (52), wherein the light transmission area (60) provides transmission of light from the inner end (62) to the outer end (63), an image acquisition system (70) arranged inside or on the body (51), and an optical coupling (80) arranged in or extending into the light transmission area (60), wherein the optical coupling (80) is optically coupled to the image acquisition system (70) in a light-transmitting way.

Abstract: A pilot-operated hydraulic directional cartridge valve includes an installation sleeve and a control slide. The installation sleeve includes a bore, a first portion towards its front end face, a third portion towards its rear end face, and a second portion between the first and third portions. The first portion has a first external sealing diameter and the third portion has a second external sealing diameter greater than the first external sealing diameter. The second portion includes radial openings and possesses an external diameter greater than first external sealing diameter and smaller than the second external sealing diameter in the region of the radial openings. The control slide is guided in the axial direction on a guide diameter of the installation sleeve, behind the radial openings. The ratio between the first external sealing diameter and the guide diameter is in the range between 1.10 and 1.22.

Abstract: The present disclosure relates to a load dependent flow control system for directing hydraulic fluid to a hydraulic actuator. The load dependent flow control system includes a closed-center valve device for controlling hydraulic fluid flow to the actuator. The closed-center valve device includes a valve spool and an electro-actuator that adjusts a position of the valve spool to adjust a rate of the hydraulic fluid flow supplied to the hydraulic actuator. A pressure sensor is provided for sensing a pressure of the hydraulic fluid provided to the hydraulic actuator. The system also includes an electronic controller configured to receive an operator flow command from an operator interface. The operator flow command corresponds to a base flow through the closed-center valve device. The electronic controller interfaces with the electro-actuator of the closed-center valve device and with the pressure sensor.

Abstract: A valve control apparatus comprises: a generator configured to generate a first set pressure signal; and a valve opening controller configured to perform the first valve opening control on the basis of the target pressure and, after the first valve opening control, perform the second valve opening control performing feedback control on the basis of a difference between the first set pressure signal and the chamber pressure. The generator generates the first set pressure signal on the basis of a first set pressure locus converging from the chamber pressure at the time of switching from the first valve opening control to the second valve opening control to the target pressure with a predetermined time constant.

Abstract: A system for intelligent monitoring and management of an electrical system is disclosed. The system includes a data acquisition component, a power analytics server and a client terminal. The data acquisition component acquires real-time data output from the electrical system. The power analytics server is comprised of a real-time energy pricing engine, virtual system modeling engine, an analytics engine, a machine learning engine and a schematic user interface creator engine. The real-time energy pricing engine generates real-time utility power pricing data. The virtual system modeling engine generates predicted data output for the electrical system. The analytics engine monitors real-time data output and predicted data output of the electrical system. The machine learning engine stores and processes patterns observed from the real-time data output and the predicted data output to forecast an aspect of the electrical system.

Abstract: A flow node includes characterized restrictor in series and adjacent with a valve to provide a primary flow restriction with a minimized volume between the two. A conductance of the characterized restrictor is low enough relative to the valve seat to cause a pressure drop that is sufficiently large relative to the pressure drop across the valve seat that a pressure measurement device is located upstream of the valve is used to determine the pressure to the inlet of the restrictor. A vent can be included to reduce bleed time. Multiple flow nodes in parallel increase a dynamic range.

Abstract: A gas supply system according to the present disclosure includes a first flow channel connected to a first gas source of a first gas, formed inside a ceiling or a sidewall of the treatment container, and communicating with the treatment space through a plurality of first gas discharge holes. The gas supply system also includes a second flow channel connected to a second gas source of a second gas, formed inside the ceiling or the sidewall of the treatment container, and communicating with the treatment space through a plurality of second gas discharge holes. The gas supply system further includes a plurality of first diaphragm valves, wherein each of the first diaphragm valves is provided between the first flow channel and the first gas discharge hole to correspond to the first gas discharge hole.

Abstract: A circuit that can be used to add a flow meter to an existing set of wires that connects a controller to an electric valve. The circuit does not require the need to run additional wiring from the controller to the valve and flow meter. The circuit creates pulses of current with a rate that is proportional to the flow, which are then transmitted to a receiver and converted to a flow measurement output to the user by a controller.

Abstract: Fluid mixing system for mixing components for a fluid product comprising a mixing regulator for mixing the components and a feed comprising at least two separate conduits, where a base component can be supplied to the mixing regulator in a first conduit and a component to be admixed in a second conduit, where a first sensor for determining the concentration of a chemical compound in the component to be admixed and a Brix sensor for determining a Brix value of the component to be admixed are disposed upstream of the mixing regulator in the second conduit and where a control unit is provided which can control the mixing process of the components by the mixing regulator in dependence of the concentration measured and the Brix value measured.

Abstract: The present disclosure describes a fuel system for an engine. The fuel system includes a fuel metering valve, a flow measuring system, and a controller in communication with the fuel metering valve and the flow measuring system. The fuel metering valve is operable to meter a flow rate of fuel based on a stroke of the fuel metering valve. The flow measuring system is configured to measure a mass flow rate of the fuel leaving the fuel system at a bandwidth greater than 20 Hz. The controller is configured to dynamically adjust the stroke of the fuel measuring system based on the mass flow rate of the fuel measured by the flow measuring system to change the flow rate of the fuel.

Abstract: A monitoring sensor for metered amounts of powder includes a sensor sleeve to channel the metered amount of powder through it and a sensor base body, in which the sensor sleeve is held interchangeably. A holding plate is attached to the interchangeable sensor sleeve. The sensor base body has a contact surface for the holding plate. The monitoring sensor includes a holding magnet for pressing the holding plate against the contact surface.

Abstract: In one embodiment, a system for controlling the delivery of process gas has a first mass flow device and a pressure transducer. The first mass flow device has a substrate block with an inlet conduit and an outlet conduit. A proportional valve having a first valve body is mounted to the substrate block and fluidly connected to the inlet conduit. A characterized restrictor is fluidly connected to the proportional valve and the outlet conduit.

Abstract: A fluid control system and associated method for pulse delivery of a fluid includes a shutoff valve and a mass flow controller (MFC) upstream of the shutoff valve. The MFC includes a flow channel, a control valve to control flow of fluid in the flow channel, a flow sensor to measure flow rate in the flow channel, and a controller having a valve input from the shutoff valve indicating opening of the shutoff valve. The controller is configured to respond to the valve input to control flow of fluid through the control valve to initiate and terminate a pulse of fluid from the flow channel to the shutoff valve to control a mass of fluid delivered during the pulse of fluid. The valve input can be a pressure signal, and the MFC can include a pressure sensor to sense the pressure signal.

Abstract: In a closed loop control method for an electropneumatic field device, an electronic target value input of a command variable corresponding to a target value of a control center is received by the open loop and/or closed loop control electronics, an electronic output for a manipulating variable to pilot the electropneumatic converter is generated by the open loop and/or closed loop control electronics; and, in a predetermined operating condition of the field device, the manipulating variable is determined by a closed loop control algorithm based on the command variable and on another controlled variable different from an actual control member position measurement value.

Abstract: There is provided an apparatus for detecting the deteriorating health of a patient receiving gas from a respiratory device. The apparatus comprises a sensor unit configured to monitor a flow rate or pressure of a gas that is flowing in a pipe that connects the respiratory device to a gas delivery device worn by the patient, and a processor configured to measure a respiratory rate of the patient based on variations in the flow rate or pressure of gas in the pipe and to implement a trend analysis of the measured respiratory rate. The processor is configured to generate a warning when it determines that there is an upward trend in the measured respiratory rate and that a magnitude of the trend exceeds a threshold.

Abstract: A microelectromechanical system (MEMS) device can be used for quantitative mechanical testing of materials within a controlled (chemical and temperature) environment, with the ability for electrochemical control to the specimen, that is coupled with a complimentary in-situ characterization technique.

Abstract: A hydraulic motor drive system controls the pressure of the hydraulic fluid delivered to a motor by a variable pressure source to control the rotation of a high inertial load rotary member driven by the motor. The speed of the motor and/or rotary component is monitored and changes in the speed are controlled by changing the pressure of the hydraulic fluid delivered to the motor.

Abstract: A valve having a balancing function for a fluid distribution system. A valve closing member is movable between a closed position and a fully opened position. An actuation device is provided for changing the position of the valve closing member. A control unit is provided and includes an electronic memory adapted to receive and store an opening limitation value, the opening limitation value being representative of a selected intermediate position between the closed position and the fully opened position of the valve closing member, wherein the control unit controls the actuation device to limit the movement of the valve closing member to positions from the closed position to the selected intermediate position. Also, a valve system and to a method of operating a valve.

Abstract: A flow-rate monitoring system may include a position sensor, a strain gauge, and a computing device for determining a rate of fluid flow through a pump using strain measurements. The strain gauge may determine strain in the chamber. The position sensor may determine the position of a crankshaft coupled to a plunger in the chamber. The computing device may receive signals generated by the strain gauge and the position sensor related to the strain in the chamber and the position of the crankshaft and process the signals to determine a flow rate through the chamber of the pump.

Abstract: A hydraulic power unit (HPU) configured for use with a pressure relief valve (PRV) having an open port and a close port is provided. The HPU includes a pneumatic primary pump, a hydraulic fluid reservoir, an accumulator, and a two position solenoid directional valve (TPSDV). The hydraulic fluid reservoir is in fluid communication with the primary pump. The TPSDV is in communication with the primary pump, the reservoir, the accumulator. The TPSDV is configured for fluid communication with the PRV. The HPU is configurable in a PRV fail open configuration and a PRV fail close configuration.

Abstract: An automated fluid flow control system with accelerated speed of response includes a programmable controller and a flow control device. The programmable controller includes a look-up table and a fine-adjustment software routine. The flow control device may be an angularly adjustable damper in a duct or a fan blower in a duct. A rotation device is used to rotate the damper blade. The rotation device rotates the damper blade to a specific angle according to a control signal value, which is associated with a fluid flow rate. The angle of the damper blade is associated with a fluid flow rate in the duct by sampling flow rate during commissioning. The fine-adjustment software routine includes sampling the fluid flow rate and increasing or decreasing the control signal value to obtain the desired fluid flow rate with the flow control device. A motor drive controller is used to drive the fan blower.

Abstract: A mass flow controller and associated methods for providing indicated flow from the mass flow controller are disclosed. The method may include obtaining a measured flow signal indicative of a mass flow rate of a fluid that is controlled by the mass flow controller and filtering the measured flow signal to generate indicated flow that provides a representation of the actual mass flow rate of the fluid. The indicated flow is provided to an operator of the mass flow controller, and a rate of change of the mass flow rate of the fluid is determined based upon samples of the measured flow signal. A time constant used in connection with the filtering is then adjusted based upon the rate of change of the mass flow rate.

Abstract: The disclosed embodiments include a valve assembly (300) that includes a piezo stack (308); a piezo actuator (306) encompassing the piezo stack, the piezo actuator having flexural elements (304) that provide a stroke multiplier that amplifies movement of the piezo stack; a valve block (318) having an inlet flow path (320) and an outlet flow path (322); a diaphragm (314) seated atop the valve block, wherein an outer part of the diaphragm is rigid and an inner part of the diaphragm is moveable in a vertical axis; and a bi-lateral flexure (312), wherein a bottom part of the piezo actuator is mechanically attached to the diaphragm via the bi-lateral flexure.

Abstract: A system and method for predicting failure conditions on a valve assembly. The method can include stages for comparing a maintenance variable to a threshold criteria, each related to an operating feature that uses operating data to quantify operation of a valve assembly, the threshold criteria associating an operating pattern found in the operating data with a failure mode on the valve assembly. The method can also include stages for selecting a maintenance task according to a relationship between the maintenance variable and the threshold criteria, the maintenance task related to the failure mode. The method can further include stages for generating an output conveying the maintenance task.

Abstract: A second core calculates an intervening variable that is defined by an inner function, when a time derivative of a state variable is expressed by a function having the state variable, the inner function, and an observable input variable as independent variables. A first core calculates a function by using respective values of the state variable, the intervening variable, and the input variable, and obtains a value of the state variable by time-integration of a value of the function. In the calculation of the function, the value of the state variable calculated in previous time, a value of the intervening variable calculated by the second core in the previous time, and a value of the input variable inputted in this time are used.

Abstract: A system receives a plurality of data samples associated with a control valve with each of the plurality of data samples associated with a setpoint and a position. A first subset of the data samples that are in a control zone associated with normal operation of the control valve is determined. In a case that a second subset of the data samples are determined to be (i) not in the first subset and (ii) close to a minimum position of the plurality of data samples and (iii) have setpoints less than their associated positions, an alert associated with a low obstruction is indicated. In a case that a second subset of the data samples are determined to be (i) not in the first subset and (ii) close to the maximum position of the plurality of data samples and (iii) have setpoint greater than their associated position, an alert is indicated.

Abstract: A device for receiving, without play, a syringe in a fluid-dispensing apparatus has at least two elastically prestressable clamps that grip the flange of the syringe plunger, and an elongated hole is provided for each clamp, such that during operation the clamp grips the plunger flange and slides in the elongated hole while simultaneously moving in a rotational and translatory manner.

Abstract: A compact, on-airway, respiratory gas analyzer for performing pulmonary function tests incorporates an IR spectroscopy light guide having a curved, rather than linear, sample chamber that lies transverse to a direction of respiratory gas flow. Cooperating with the sample chamber is an impact plate that functions to steer respiratory and test gases impinging on the impact plate into the curved sample chamber. A source of IR energy is at one end of the sample chamber and an electro-optical sensor responsive to IR energy is disposed at an opposite end of the chamber. The respiratory gas analyzer also includes gas flow paths and valving for carrying out lung capacity and lung diffusion tests.