Abstract: The present invention is directed to a rest room control system including one or more sensors configured to monitor or control a function associated with the rest room. The system also includes a controller operably coupled to the one or more sensors, and configured to receive data therefrom associated with the function, and communicate a status condition associated with the function in response thereto.

Abstract: A method for controlling liquid delivery in a processing chamber. The method includes generating an analog input (AI) signal proportional to a process variable and calculating an analog output (AO) signal based on a setpoint and a deadband. The setpoint is a target value of the process variable and the deadband is an allowable tolerance around the setpoint that determines when the control logic is activated to control the process variable. The method further includes transmitting the AO signal to a control device and adjusting the process variable proportional to the value of the AO signal.

Abstract: Methods and apparatus for rapid gas recovery in a controlled gas atmosphere enclosure, which are particularly suited for maintaining incubator gas concentration levels, include the formulation of algorithms utilized for this purpose. The algorithms are included in the firmware for an embedded controller and operate gas solenoids that have inputs defined as specific gases at a defined pressure. An application of the rapid gas recovery method and apparatus to incubators is also disclosed.

Abstract: Described herein are apparatuses, methods and systems to monitor the performance of one or more mass flow controllers that supply gases to deposition, etching, and other manufacturing processes. A bypass loop is provided in fluid connection from either the process line or the vent line. In the bypass loop is a flow detector, such as a digitized mass flow controller. The flow detector takes one or more measurements of flow of gas from a mass flow controller, and data from such one or more measurements is used to provide information about the accuracy and/or precision of the mass flow controller. Also disclosed are ways to correct for back pressure or back vacuum in the process line.

Abstract: An acoustic flowmeter calibration method and sampling system address a variation in acoustic transducer delay time with increasing temperature. In one aspect, calibration of the path length between the sending and receiving transducers and calibration of the transducer delay time over a wide temperature range are optimized. In another aspect, the flowmeter output is temperature compensated based on the exhaust flowmeter gas temperature. These two aspects may be embodied in an ultrasonic flowmeter for exhaust gas measurement individually or in combination in accordance with the invention.

Abstract: The invention relates to a device for determining a measurement of mass flow of fluid for a combustion chamber comprising a fluid metering device and a means of measuring the position of the metering device being measured.

Abstract: An indicator for displaying either low liquid level or satisfactory liquid level conditions within a tank includes a sensor for detecting the liquid level conditions, a photodetector for detecting an ambient dark condition, a pair of indicator lights for indicating either the low liquid level or satisfactory liquid level conditions, and electrical circuitry operable to illuminate one of the indicator lights upon detection of the ambient dark condition by the photodetector and detection of either the low liquid level condition or satisfactory liquid level condition by the sensor.

Abstract: A method and system for vehicle emission testing measures pollutant concentration, but then provides for conversion of the measured pollutant concentration into its corresponding pollutant mass, thereby allowing for the calculation of a vehicle's emission test scores for one or more common pollutants in units of mass per distance. Through the use of the method and system of the present invention, significantly more accurate results can be obtained as compared to prior art test methods, and without the implementation, operating, and maintenance costs of comparable test methods.

Abstract: A portable apparatus for calculating respiratory oxygen consumption comprising a housing having a fluid inlet, a flow sensor, mounted within the housing, an oxygen sensor and means for calculating the respiratory oxygen consumption using data obtained from the oxygen sensor and the flow sensor. The invention also relates to a method of calculating respiratory oxygen consumption.

Abstract: A vehicle exhaust measurement system is provided includes that a conduit having a conduit inlet and a conduit outlet. A make-up air tube is connected to and is in fluid communication with the conduit inlet. The make-up air tube provides make-up air for mixing an exhaust gas. A mixed gas tube is connected to and is in fluid communication with the conduit outlet. The mixed gas tube conveys a mixture of make-up air and exhaust gas to analysis equipment. In the preferred embodiment, the exhaust gas tube extends through an outer wall of the conduit. A mixing plate is arranged in either the conduit or the mixed gas tube with the exhaust gas tube extending to a position adjacent to the mixing plate. The exhaust gas tube conveys the exhaust gas to the mixing plate to mix the exhaust gas and the make-up air at the mixing plate.

Abstract: Apparatus and methods of calibrating a microfluidic flow sensor, in which the flow of a fluid through a flow sensor is stopped and a first value is read from the flow sensor, then the fluid is pumped through the flow sensor sequentially at first and second selected rates, and readings from the flow sensor of the flow rate are taken for each of the rates. The readings are used in a polynomial equation to determine the actual flow rate, which is used to calibrate the sensor. The flow sensor can be connected to a computer programmed to perform the calibration method, determine the actual flow rate of the sensor, and make appropriate adjustments to the flow rate of a pump.

Abstract: A multi-component fluid mix ratio check nozzle includes a base engageable with a multi-component fluid dispensing gun for receiving fluid components dispensed from the gun. At least two hollow extensions extend from the base, wherein each of the extensions provides a passageway for at least one of the components of the multi-component fluid without mixing with the other fluid components of the multi-component fluid. In one embodiment, the mix ratio check nozzle forms part of a kit including a fluid flow adjusting means for adjusting the mix ratio of the fluid components.

Abstract: A flowmeter proving device and method for use in proving a flowmeter in situ under operating conditions comprises a pair of standard Coriolis based mass flowmeters (2, 3) which are connected together in series by a conduit (7) connecting the fluid outlet (23) of the first flowmeter (2) to the fluid inlet (32) of the second flowmeter (3). A valved fluid supply conduit (4) is connected to the fluid inlet (22) of the first flowmeter (2), and a valved fluid return conduit (8) is connected to the fluid outlet (33) of the second flowmeter (3). These supply and return conduits (4 and 8) enable the device to be connected to a fluid flow line containing a flowmeter which is to be proved such that fluid flowing in the flow line will flow in series through the flowmeter to be proved and the two flowmeters (2 and 3) of the proving device.

Abstract: Temperature compensation methods for physical property sensors are disclosed herein, based on a simple bridge circuit. An imbalance of the bridge circuit can be driven to a zero value, while a supply voltage thereof is simultaneously driven to a level required to bring the heating element to the temperature rise above ambient temperature that optimally compensates for a number of temperature-dependent effects. The heating element can be configured as a thin-film heating material. The resulting total temperature dependence of the measuring system, which includes the heating element, the bridge-circuit with amplifier and the fluid to be measured, can be reduced to a level at which the need for additional digital temperature compensation circuitry and its associated costs may be reduced.

Abstract: Descriptions are provided for implementing flowmeter zeroing techniques. In operating a flowmeter, it may be the case that, if not properly calibrated, the flowmeter will produce erroneous measurements, e.g., will indicate a non-zero flow during a period of zero flow. By determining a magnitude of such erroneous measurements, calibration values may be determined, which may later be used to adjust a measurement that is output by the flowmeter and thereby improve an accuracy of the flowmeter. Such calibration values may be determined for a plurality of operational conditions associated with the flowmeter, such as densities of materials being measured, and/or configurations of flow elements associated with transporting material to the flowmeter. Then, the calibration values may be correlated with the relevant operational conditions, and stored for later use.

Abstract: A vehicle exhaust measurement system is provided includes that a conduit having a conduit inlet and a conduit outlet. A make-up air tube is connected to and is in fluid communication with the conduit inlet. The make-up air tube provides make-up air for mixing an exhaust gas. A mixed gas tube is connected to and is in fluid communication with the conduit outlet. The mixed gas tube conveys a mixture of make-up air and exhaust gas to analysis equipment. In the preferred embodiment, the exhaust gas tube extends through an outer wall of the conduit. A mixing plate is arranged in either the conduit or the mixed gas tube with the exhaust gas tube extending to a position adjacent to the mixing plate. The exhaust gas tube conveys the exhaust gas to the mixing plate to mix the exhaust gas and the make-up air at the mixing plate.

Abstract: A gaseous fuel storage system included in a vehicle to supply fuel to a power source (e.g., an engine, fuel cell and the like) is diagnosed and controlled by a monitoring/evaluation and control system. Various parameters with reference to gas temperature, gas pressure, gas density and damage and shock of a vessel containing the pressurized gas are provided by respective sensors mounted on and in vessels of a gas storage system. A control module determines whether maintenance of the vessels is required based on the sensed parameters. If maintenance is necessary, the components will be replaced with new ones or the entire gas storage system or the vessel will be replaced. If necessary, a warning is provided to avoid operation of the power source and the vehicle.

Abstract: The present invention generally provides a closed feedback system for operating peripheral devices in response to environmental conditions. Illustrative environmental conditions include well bore pressure, line pressure, fluid levels, flow rates and the like. In one embodiment, a flow controller disposed in a fluid line is operated in response to operating variable readings (e.g., pressure and/or flow rate) taken in the flow line and/or a well bore. The variable measurements are then compared to target values. If necessary, the flow controller is closed or opened to control the rate of fluid flow through the flow line and thereby achieve the desired target values. In another embodiment, the operation of a pump motor is monitored. Operating variables, such as voltage, current and load, are measured and compared to target values.

Abstract: A method for detecting a malfunction of a sensor measuring a measured quantity is provided, in which a signal-range check for the output signal of the sensor is performed, provided that the measured quantity is within a permissible range. If the measured quantity is outside the permissible range, no signal-range check is performed, but the output signal is used for detecting the measured quantity and for further calculations. The sensor may be, for example, a hot-film air-mass meter. If this is the case, the measured quantity is the drawn-in air mass, and the signal-range check is performed, provided that the engine operating state and thus the drawn-in air satisfies specifiable conditions. In addition to the signal-range check, onboard diagnoses with regard to specifiable plausibility criteria relating to the offset-drift and/or the sensitivity-drift of the sensor may also be performed.

Abstract: A vacuum flow measurement device measures the quantity of air flowing into a high-volume evacuator (HVE) vacuum tip commonly found in dental treatment rooms. The device includes a tubular member constructed to mimic internal structural characteristics of a HVE tip. The tubular member includes a valve end coupleable with a HVE valve and an open end. A pressure gauge is connected to the tubular member via a port spaced from the open end of the tubular member. When the vacuum flow measurement device is coupled with the HVE valve, an air flow rate is determined as a function of pressure measured via the pressure gauge.

Abstract: An apparatus for measuring a gas concentration comprises a conduit through which an objective gas to be measured flows, a ultrasonic transmitting and receiving element fixed in a straight portion of the conduit and a reflecting plate fixed in the straight portion to face to the ultrasonic transmitting and receiving element. The apparatus further comprises a calibration gas source for supplying a calibration gas of which components and component ratio are preliminarily known, temperature sensors for measuring the temperature of the calibration gas flowing through the conduit, a propagation time calculating means for calculating the time period for propagation of the ultrasonic through the calibration gas in the conduit, a calibration means for calibrating the reference distance between the ultrasonic transmitting and receiving element and the reflecting plate based on the calculation results of the propagation time calculating means.

Abstract: A check rod (1) for apparatus for measuring properties of longitudinally permeable rods, the check rod (1) comprising a hollow cylindrical body (2) having first, second and third transverse walls (4, 5, 6); a first chamber (17) defined by body (2) and the first and second transverse walls (4, 5); a second chamber (8) defined by body (2) and the second and third transverse walls (5, 6); at least one first ventilation window for air to flow laterally into chamber (7); at least one second ventilation window for air to flow laterally into chamber (8); and tubes (9, 10, 11) which are open at each end and provide for laminar air flow therethrough which is the only flow of air through the transverse walls, said tubes comprising at least one short tube (9) which passes through wall (4) and opens into chamber (7); at least one intermediate length tube (10) which passes through walls (5, 6) and opens into chamber (8), and at least one long tube (11) which passes through all walls (4, 5, 6) to allow passage of air throu

Abstract: A method and apparatus for monitoring or calibrating a gas flow rate through a mass flow controller, for example, in a semiconductor fabrication process. A reference mass flow controller is disposed in a vent bypass loop for receiving gas flow from one of a plurality of mass flow controllers associated with a like plurality of supply gases. One of the gas supply mass flow controllers is selected and commanded to a specific gas flow rate. The gas flow through the selected mass flow controller also passes through the reference mass flow controller as the gas flows to a vent. Comparing the gas supply mass flow controller commanded flow rate with the actual flow rate as determined by the reference mass flow controller provides monitoring and calibration of the gas supply mass flow controller.

Abstract: A system and method is provided for remotely and automatically calibrating a mass-flow sensor in a yield monitor of a combine. The invention uses a wireless communication device installed on a combine and a remote wireless communication device installed on a grain carrier or truck carrier. Once an actual weight is obtained, calibration information is sent to the combine to calibrate the mass-flow sensor.

Abstract: A flowmeter proving device and method for use in proving a flowmeter in situ under operating conditions comprises a pair of standard Coriolis based mass flowmeters (2, 3) which are connected together in series by a conduit (7) connecting the fluid outlet (23) of the first flowmeter (2) to the fluid inlet (32) of the second flowmeter (3). A valved fluid supply conduit (4) is connected to the fluid inlet (22) of the first flowmeter (2), and a valved fluid return conduit (8) is connected to the fluid outlet (33) of the second flowmeter (3). These supply and return conduits (4 and 8) enable the device to be connected to a fluid flow line containing a flowmeter which is to be proved such that fluid flowing in the flow line will flow in series through the flowmeter to be proved and the two flowmeters (2 and 3) of the proving device.

Abstract: A low impedance encoder generally comprises a clock source and a switch. The clock source operates according to a predetermined duty cycle. The switch has a first position, closed, and a second position, opened. The duty cycle controls a current flow the switch. A high current flow through the switch indicates that the switch is closed and that the consumption of a utility as registered by the utility meter has occurred; the switch will continue to open and close throughout the process of metering. A low current flow through the switch indicates that the switch is open.

Abstract: A calibration rig for calibration and/or re-calibration of flow meters (5) and/or flow meter calibration carts (7) is described comprising: a source (1) of pure sterilized water or a source (40) of a sterile conductive solution, a piping manifold (3) connected to the source (1), at least one flow meter (5) connected to the source (1) via the piping manifold (3) and/or at least one flow meter calibration cart (7) connected to the source (1) via the piping manifold (3) and a drain pipe (23) connected to each flow meter (5) and to each flow meter calibration cart (7) to guide liquid from the flow meter (5) and/or the flow meter calibration cart (7) to a drain (23).

Abstract: A system, method, and software are disclosed that determine a proportion of a majority component of a fluid that is flowing through a Coriolis flowmeter. Circuitry receives pickoff signals and a temperature signal from the Coriolis flowmeter responsive to the fluid being flowed through the Coriolis flowmeter. The circuitry processes the pickoff signals and the temperature signal to determine a proportion of the majority component relative to the fluid. To determine the proportion of the majority component in one example, the circuitry determines a first volumetric flow rate based on a measured mass flow rate of the fluid and a reference density of the majority component. The circuitry then determines a second volumetric flow rate based on a measured volumetric flow rate, a temperature-varying density, and the reference density. The circuitry determines the proportion of the majority component based on the first volumetric flow rate and the second volumetric flow rate.

Abstract: A constant flow of air through a personal air sampler is provided regardless of changes in the air flow path, by altering the pump speed as a function of the power taken by the pump. The characteristics of the pump are precalibrated to provide a constant used together with the square of the voltage appearing across the motor armature coils (applied voltage minus back Emf), which reflects the power currently used, to adjust the motor speed and thus provide a constant flow of air under changing conditions of resistance.

Abstract: A calibration rig for calibration and/or re-calibration of flow meters (5) and/or flow meter calibration carts (7) is described comprising: a source (1) of pure sterilized water, a piping manifold (3) connected to the source (1), at least one flow meter (5) connected to the source (1) via the piping manifold (3) and/or at least one flow meter calibration cart (7) connected to the source (1) via the piping manifold (3) and a drain pipe (23) connected to each flow meter (5) and to each flow meter calibration cart (7) to guide water from the flow meter (5) and/or the flow meter calibration cart (7) to a drain (23).

Abstract: A method and apparatus for in-situ calibration of quantity measurement of a fluid flowing in a channel, in which a device for measuring the volume of the fluid is disconnected from the fluid flow, measuring fluid is accumulated in a pre-determined amount on site of the calibration, this pre-determined amount of measuring fluid is led through the measuring device with a pre-determined volume flow, in the course of which the volume values measured by the measuring device are saved, then the measured volume values and the real values of the fluid led through are compared to each other and, with this, the quantity measurement of the flowing fluid is calibrated.

Abstract: A system and method is provided for remotely and automatically calibrating a mass-flow sensor in a yield monitor of a combine. The invention uses a wireless communication device installed on a combine and a remote wireless communication device installed on a grain carrier or truck carrier. Once an actual weight is obtained, calibration information is sent to the combine to calibrate the mass-flow sensor.

Abstract: An apparatus 10,70 and method is provided that includes a spatial array of unsteady pressure sensors 15-18 placed at predetermined axial locations xl-xN disposed axially along a pipe 14.for measuring at least one parameter of a saturated vapor/liquid mixture 12, such as steam, flowing in the pipe 14. The pressure sensors 15-18 provide acoustic pressure signals P1(t)-PN(t) to a signal processing unit 30 which determines the speed of sound amix propagating through of the saturated vapor/liquid mixture 12 in the pipe 14 using acoustic spatial array signal processing techniques. The primary parameters to be measured include vapor/liquid concentration (i.e., steam wetness or steam quality), vapor/liquid mixture volumetric flow, mass flow, enthalpy, density and liquid droplet size. Frequency based sound speed is determined utilizing a dispersion model to determine the parameters of interest.

Abstract: A vacuum network control system includes a vacuum network controller hub communicating over a public high-speed network, where the hub has an address registered with respect to the non-local network and communicates over a first local high-speed network. Vacuum network controllers (VNCs) communicate with the hub over the first local network. Each VNC has a dynamically assigned local address and communicates with at least one component intrabus module over a second local high-speed network. Each module has a dynamically assigned local address and further communicates with one or more monitor and control end units over a local device network. Each monitor and control end unit has a dynamically assigned address. Monitor and control end units include taps, which provide at least one of analog, digital or serial I/O, and components, for example, vacuum pumps.

Abstract: A method and apparatus for testing sensors in a fluid flow conduit to verify the accuracy of the flowmeter of which the sensors are a part. Where two similar sensors are employed, active and reference sensor functions are interchanged to verify their functioning accuracy. Alternatively, different stimulation levels can be used to provide a basis for cross-correlation of sensor outputs. A single, or multiple, time-shared sensor can be employed in place of two sensors. Transient or steady state responses are employed. Many sensor types can be used.

Abstract: Fluid flow in a conduit is measured with an acoustic Doppler system installed in an opening in the pipe. The Doppler system may include transducers and driving circuitry to produce narrow beam pulses of acoustic energy. The transducers may be coupled to an acoustic refractive lens which is sealed in the opening.

Abstract: An apparatus and method for simulating a package pressure burst condition for calibrating a package pressure burst detector, where the package pressure burst detector is connected to a pressure tank, and the detector applies an air flow into the tank to gradually increase the tank pressure, and the tank has an output relief conduit connected to a pressure relief valve via a pressure switch, wherein the pressure relief valve is activated for a predetermined time when the pressure switch detects a preset pressure in the tank.

Abstract: A magnetically coupled, small volume, positive displacement, multi-axial, isokinetic, flow sensor calibrator or prover has one or more, serially interconnected flow tubes, through which a cylindrical, convoluted, displacer, with embedded, omni-directional magnet(s), and anti-compression device(s), sequentially, isokenetically dispenses calibration fluid through test flow sensor(s). An oscillating volume detector actuator magnetically coupled to the displacer has concentric, or parallel, outer rings connected to an inner, common center ring, with integral volume detector sensor initiator projection. The volume detector actuator outer ring(s) and center ring oscillate coaxially, respectively, with each flow tube, and a volume detector rod with integral volume detector sensors, sequentially activated by the initiator projection.

Abstract: A universal calibration apparatus and method to estimate the dispense output from a low volume, non-contact, liquid dispensing systems that may be applied for every hardware configuration (e.g., tube length, orifice diameter, tip design, etc), reagent solution property and environmental condition. This same calibration technique is applied to calibrate or tune these non-contact liquid dispensing systems to dispense desired volumes (in the range of about 0.050 &mgr;L to 50 &mgr;L), irrespective of the hardware configuration or the solution properties. That is, the calibration technique is not dependent on any variables, but the result (the actual dispense volume) is dependant on the variable mentioned. By actuating selected pulse widths, and measuring the resulting volume, a Calibration Profile can be generated correlating the liquid volume dispensed from the orifice to the respective pulse width of the dispensing valve thereof through calibration points..

Abstract: The present invention generally provides methods and systems for monitoring and controlling electroosmotic flow rates in microfluidic systems. Generally, such methods and systems monitor flow rates in electroosmotically driven microfluidic systems by flowing signaling elements within these channels and measuring the flow rate of these signals. The methods of monitoring flow rates are also applied to methods and systems for continuously monitoring and controlling these flow rates in electroosmotically driven microfluidic systems.

Abstract: A fluid system such as a fire sprinkler system or a device such as a pressure reducing valve is tested by fitting to the system or device at least one outlet device whose characteristics are known, causing fluid to flow under test conditions, and measuring the fluid flow through the outlet device to give an indication of which flow would take place under normal operating conditions. The outlet device may be a flow restrictor.

Abstract: A parameter sensor including a conduit configured to contain a material is controlled. A first excitation applied to the conduit is determined. Motion of the conduit in response to the first excitation is determined. A second excitation to apply to the conduit is determined from the determined first excitation, the determined motion in response to the first excitation, a desired motion for the conduit, and a frequency response for the conduit. In particular, excitations may be iteratively determined and applied to the conduit, and motion signals representing motion of the excited conduit may be processed to generate process parameter estimates, such as mass flow rate estimates. The frequency response may be assumed to be time-invariant, or may be adaptively estimated. The invention may be embodied as methods, apparatus and computer program products.

Abstract: A measuring instrument, especially a flowmeter, whose measuring operation consists in the quantification of an output value as a function of an input value. According to the invention, the input value can be varied, the output value corresponding to a given input value can be measured, and a malfunction of the measuring operation of the measuring instrument can be detected on the basis of a deviation, beyond an established threshold value, of the output values measured at different input values, from the output value expected as a function of the relationship between the input value and the output value. The measuring instrument thus permits reliable and simple determination of a malfunction in the measuring operation by virtue of a self-test.

Abstract: A flow meter system that calculates mass flow rate based only on a single pressure signal. A flow controller is arranged in parallel with a restriction such that a constant pressure differential is maintained across the restriction. The pressure, and temperature if not controlled, of the fluid flowing through the restriction is measured on either side of the restriction. The pressure is compared to a plot of pressure versus mass flow rate calculated for the specific restriction and fluid being measured. The constant pressure differential maintained across the restriction yields a linear relationship between pressure and flow rate. If temperature is not controlled, the plot of pressure versus mass flow rate will remain linear, but the slope of the curve will be adjusted based on the temperature of the fluid.

Abstract: A system for monitoring the emission of VOCs in a workstation is disclosed including a sensor to obtain a signal representative of the amount of coating discharged in the workstation, a database for storing data values representative of the signal, a network configured for allowing access to the database and at least one computing device for access to the database over the network and providing a user interface for presenting information representative of at least a portion of the data values. A method for monitoring the emission of VOCs in a workstation is disclosed.

Abstract: In one embodiment, A hydrogen gas detector calibration system comprises: a mixing tube; a first conduit in fluid communication with a hydrogen-free gas, wherein the first conduit comprises a first orifice in fluid communication with the mixing tube; an electrolysis cell for generating hydrogen gas; a second conduit in fluid communication with the hydrogen gas, wherein the second conduit comprises a second orifice in fluid communication with the mixing tube; and the hydrogen gas detector in fluid communication with the mixing tube.

Abstract: A method for testing a Coriolis transducer having a mass adapted vibrate along a vibratory direction in a resonant structure and undergo a displacement along a sensitive axis, perpendicular to the vibration, in response to an angular rate about a mutually perpendicular rate sensing axis. In the absence of an angular rate about the rate sensing axis, forces, FTEST VIBRATORY and FTEST SENSITIVE are applied on the mass along the direction of vibration and along the sensitive axis, respectively, in a predetermined ratio, N. The output VOUT TEST of the transducer is measured in response to the forces, FTEST VIBRATORY and FTEST SENSITIVE.

Abstract: Sensor failure in an oil and gas production system is monitored and detected by checking the consistency of the measurements of the sensor in question using a computer-based process model with the measurements of the other sensors in the system. The present invention also generates a back-up value for a failing sensor with the process model by identifying the value that is most consistent with the measurements of the other sensors in the system.

Abstract: A method for monitoring the performance of internal pumps in a plant in which a coolant is driven through plural internal pumps, said method comprising measuring the pump motor power input to the motor driving said pump; estimating the power input to said pump motor during a test performed outside said plant corresponding to the pump speed and the pump flow measured within said plant; computing a pump motor input power ratio based on said measured value and said estimated value; and detecting the variation in the performance of said internal pumps.

Abstract: A heat type mass flowmeter calibration apparatus includes standard heat type mass flowmeters and sonic nozzle type mass flowmeters connected in series. Periodically or when required, the national-standard-traceable sonic nozzle type mass flowmeter that is traceable with respect to a national standard is used to calibrate the standard heat type mass flowmeters. Actual flowmeter measurements are conducted using the calibrated standard heat type mass flowmeter values. Therefore, consistently high precision of calibrations and measurements is guaranteed.