Abstract: A device measures a frictional force and a film thickness of a lubricating oil film in different surface velocity directions. The device includes an experiment bench. A translation stage is mounted to the experiment bench, and is linearly movable. A main shaft system is mounted to the experiment bench. A glass disc is mounted to the main shaft system and is rotatable. An arcuate guide rail is disposed on the translation stage. A rotary base is mounted to the arcuate guide rail and is movable along the arcuate guide rail. A loading system is mounted to the rotary base. A steel ball of the loading system and the glass disc are movable relative to each other. A rotary bearing in the rotary base is configured to convert a frictional force generated from the relative movement to a pressure allowed to be collected by a pressure sensor on the rotary base.

Abstract: A computer implemented method system and apparatus for determining remaining life of engine oil in an engine includes generating reference engine profile data by determining reference engine parameters of a reference engine; determining reference engine oil lubrication data based on mechanical testing of an oil sample from the reference engine; generating a reference model by associating the reference engine profile data with the reference engine oil lubrication data; receiving the reference model at an engine apparatus; measuring engine parameters relating to operation conditions of an engine of the engine apparatus; and determining remaining life of engine oil in the engine of the engine apparatus using the reference model and the engine parameters.

Abstract: An abnormality detection device for a rolling bearing includes a filter that allows passage of lubricating oil, while preventing passage of metal pieces, from the bearing space between the outer ring and the inner ring of the rolling bearing to the exterior of the bearing space. The device further includes an electrical circuit including a pair of permanent magnets mounted, as a pair of electrodes, to the filter so as to be spaced apart from each other, and electrical lines extending from the respective electrodes to a power source. A state detector detects a change in electrical output from the electrical circuit when metal pieces adhere between the pair of permanent magnets, thereby detecting the state of the metal pieces contained in the lubricating oil.

Abstract: A working fluid monitoring system for monitoring a working fluid of working fluid system of a piece of equipment is provided. The working fluid monitoring system can include a filter member having an inlet, an outlet, and a filter media disposed between the inlet and the outlet. The filter member can be configured to permit fluid communication of the working fluid of the working fluid system from the inlet, through the filter media, and out the outlet of the filter member. A sensor is in operable communication with the working fluid within the filter member and is configured to monitor in situ a parameter of the working fluid and/or the working fluid system.

Abstract: A monitoring apparatus is adapted to monitor lubricant in a hydraulic fracturing pump system, and includes a gateway and one or more sensors configured to be in communication with the gateway. The one or more sensors are configured to measure quality of the lubricant, a pressure of the lubricant, and a temperature of the lubricant. The gateway is configured to receive sensor data associated with the quality of the lubricant, the pressure of the lubricant, and the temperature of the lubricant. To monitor the lubricant, the gateway is configured to: store the sensor data on the non-transitory computer readable medium; transmit to another computing device the sensor data and/or representative data based on the sensor data; visually indicate a status of the quality of the lubricant; visually indicate a status of the pressure of the lubricant; visually indicate a status of the temperature of the lubricant; or any combination thereof.

Abstract: An assembly providing a bearing, a lubricant and a contamination sensor for determining a level of contamination in the lubricant. The sensor includes an EM wave generator for generating an EM signal, and an EM sensing element arranged in contact with the lubricant. The EM sensing element receives the generated EM signal and transmits an output signal whose properties are responsive to real and imaginary parts of a complex relative permittivity of the lubricant. The output signal is received by an EM measuring device that measures first and second parameters of the output signal, which are respectively representative of the real and imaginary parts of the complex relative permittivity. The EM measuring device determines a level of water contamination in the lubricant, based on the measured first parameter alone and determines a level of metal particle contamination in the grease, based on the measured first and second parameters.

Abstract: The invention relates to a bearing cage including a bearing cage main body made of a polymer material and having pockets for receiving at least one row of rolling elements of a bearing. The cage is provided with a passive resonant circuit including an antenna coil attached to the cage main body. It is proposed that the antenna coil is formed as a conductive layer directly attached to the cage material of the bearing cage main body and is designed so as to have a breaking point less than or equal to a breaking point of the cage material. Thus, a rupture in the cage main body ruptures the antenna coil, changing the resonance behavior of the passive resonant circuit.

Abstract: An oil deterioration suppressing apparatus for an internal combustion engine comprises a first oil filter and a second oil filter, wherein the first oil filter comprises a first filter member for filtering oil from an oil pan in which oil is stored, and the second oil filter comprises a second filter member for filtering oil from the oil pan, and wherein the second filter member is made of a ceramic material and has a mean pore size smaller than the mean pore size of the first filter member.

Abstract: Provided is a working machine capable of accurately detecting a contaminant in grease contained in a slewing mechanism. The working machine includes a lower travelling body, an upper slewing body, and the slewing mechanism. The slewing mechanism includes: a ring gear fixed to the lower travelling body and having inner teeth; a pinion disposed on the upper slewing body and rotated in mesh with the inner teeth of the ring gear; and a grease bath disposed along an inner circumference of the ring gear for storing grease. The upper slewing body includes a sensor for detecting a contaminant having a potential for contaminating and deteriorating the grease, and a sensor supporting member supporting the sensor at a position that allows the sensor to revolve while being immersed in the grease in the grease bath.

Abstract: A spherical bearing comprising: a race; a ball; a wear lining; and a capacitive sensor positioned within or behind the wear lining to gauge wear of said wear lining.

Abstract: An H2S (hydrogen sulfide) monitor includes a hydrogen sulfide sensor and a moisture sensor. In some examples, the H2S monitor emits a moisture alarm if the moisture sensor detects liquid water in an amount that exceeds or approaches a moisture tolerance limit of the hydrogen sulfide sensor. In some examples, the moisture sensor prevents the hydrogen sulfide sensor from triggering a false H2S alarm caused by moisture contaminating the hydrogen sulfide sensor.

Abstract: A tool lubrication delivery monitoring system and a method of control. An accelerometer is provided to detect a position of a valve and fluid flow through the valve. Accelerometer data may be compared to a baseline profile to determine whether fluid flow or valve operation is within established parameters.

Abstract: A method is provided for determining remaining oil life prior to an oil change in an internal combustion engine that uses a body of oil. The method includes transferring the body of oil to the engine and determining a volume of the transferred body of oil. The method also includes determining quality of the transferred body of oil and determining the remaining oil life based on the determined quality and volume of the body of oil. The method additionally includes activating an oil change indicator when the remaining oil life reaches a predetermined level. A system for determining a number of engine revolutions permitted on a volume of oil is also disclosed.

Abstract: A tangible computer readable medium includes instructions executable by a processor to cause the processor to communicate with a multicast alert server to receive a multicast emergency alert message via a multicast-enabled network of an Internet Protocol television system. The multicast emergency alert message includes data related to a location code and data related to a set-top box action. The computer program further includes instructions to execute the set-top box action when the location code matches location information stored at a set-top box device.

Abstract: A window with built-in devices that senses carbon monoxide; powered only by the exterior daylight; that automatically opens by itself and sounds an alarm when a dangerous level of carbon monoxide is sensed to release the accumulated carbon monoxide and let the clean air with fresh oxygen enter the contaminated area to prevent or minimize poisoning and/or death of humans & animals without the need of any human physical action; the provided contacts can be connected to a private alarm station to alert the Fire & Police Departments to provide immediate assistance to the endangered humans & animals and protect the opened residence.

Abstract: To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Abstract: To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Abstract: To enable an air velocity of sampling air to be precisely measured, a smoke detector (S) includes: a smoke detection part (22) connected to a sampling pipe (11); a fan (12) that sucks sampling air (SA) into the sampling pipe; and an air velocity sensor (15) that measures an air velocity of the sampling air within the sampling pipe. The air velocity sensor (15) is disposed at a primary side of the fan (12), and a straightening vane (25) is disposed between the air velocity sensor (15) and a suction port (12a) of the fan (12).

Abstract: This invention pertains to evacuation systems, more particularly, it pertains to single or networked guiding devices that utilizing pre-programming and/or virtual programming, sensing and detecting means, illumination and alarming means, symbols and text messages to direct traffic to safety. The networked guiding devices of the system are configured to systematically and progressively direct traffic from one device to the next, directing traffic to safety. The system is configured to be controlled locally or remotely, on-demand. The evacuation system is applicable to people's traffic, vehicular traffic and/or other transportation modes. The evacuation system may be used in emergency or non-emergency situations.

Abstract: A self-contained backup power source such as a battery is provided for components within an electrically powered device such as a storage controller, photocopier or the like, to maintain diagnostic status data and to power a service indicator aid, or diagnostic indicator, such as an LED. A switch selects the backup power source when a primary power source of the electrically powered device is no longer available to the component, such as when the component is removed from the electrically powered device, the primary power source is disconnected as a safety precaution when servicing or replacing the component, or a higher-level assembly, in which the component is provided, is removed from the electrically powered device. The diagnostic indicator may be powered separately from the data storage device.

Abstract: The condition of a shoe roll is monitored by a device which continuously analyzes the lubricant used in a lubrication system (14) integrated with the shoe roll. The analysis determines the amount of contaminant particles which have entered the lubricant. Particles (19) originating from the belt (13) of a belt roll belonging to the shoe roll (10) are determined in the lubricant. The condition of the belt (13) of a belt roll belonging to the shoe roll (10), and especially the condition of the inner side of the belt (13), can be determined on the basis of the amount of the particles (19).

Abstract: A generator monitoring system and method includes a plurality of sensors (12) disposed within a generator enclosure (18) to sense health conditions of a generator (10) housed within the enclosure. The sensors are interconnected to provide a single communication path (14) for allowing communication with the plurality of sensors. A monitoring device (16) outside the generator enclosure receives health condition information from each of the plurality of sensors via the single communication path. A sensor may be disposed within the generator enclosure to detect particulates emitted from a monitored portion (e.g., 52) of the generator housed within the enclosure. A sensor may be disposed proximate a bus bar connection (130) of the generator to sense a health condition of the bus bar connection and generate corresponding health condition information provided to the monitoring device.

Abstract: A cell for the measurement of resistivity and/or permittivity of a liquid, under variable ac frequency energizing, preferably includes a first set of n+1 metal plates interleaved with a second set of n places, both sets of plates preferably being of the same size and shape for the liquid filling the spaces between facing plates. The two sets of alternating plates are separately electrically interconnected. The plates are supported at their peripheries in spaced apart and insulated relationship so that, during variable ac frequency testing, current flow through the liquid is in a path perpendicular to the facing plates.

Abstract: A self-contained backup power source such as a battery is provided for components within an electrically powered device such as a storage controller, photocopier or the like, to maintain diagnostic status data and to power a service indicator aid, or diagnostic indicator, such as an LED. A switch selects the backup power source when a primary power source of the electrically powered device is no longer available to the component, such as when the component is removed from the electrically powered device, the primary power source is disconnected as a safety precaution when servicing or replacing the component, or a higher-level assembly, in which the component is provided, is removed from the electrically powered device. The diagnostic indicator may be powered separately from the data storage device.

Abstract: The present invention relates to testing equipment 20 for a fire alarm 1. It includes a testing pole (21), a range spacer (23) connected to the testing pole (21), and a reflective means and/or scattering means situated in the inside of the essentially pot-shaped designed range spacer (23).

Abstract: The invention is a power strip with an internal smoke detection device, which cuts off AC electrical power to attached electrical devices if smoke is detected.

Abstract: A method and apparatus for detecting the location of an event from amongst a plurality (A to P) of locations. Lines of communication (R1 to R4, C1 to C4), commonly pipes of a smoke detection system, cover the locations in such a fashion that the location of an event can be determined uniquely but the number of pipes is minimized.

Abstract: In a lubricant application system, a prescribed volume of lubricant is transferred from a lubricant discharge port 8 of a prescribed liquid volume discharge device to a rolling element 703 of a rolling bearing 700 in a state in which the lubricant discharge port 8 is positioned directly above and sufficiently close to the rolling element 703, whereby the lubricant is applied to the interior of the rolling bearing 700. Further, the application system inspects whether or not a prescribed volume of lubricant is injected from the discharge device for injecting a lubricant into the interior of a rolling bearing 700.

Abstract: A non-ferrous component comprising a thermally-affected adhesive applied to a surface of the component, and at least one ferrous metal wire attached to the surface of the component by the thermally-affected adhesive.

Abstract: A device capable of reducing an erroneous operation with a simple configuration in which, when two or more conductors M1, M2, M3 (three of them in FIG. 1) are attracted by three or more magnets 1a, 1b, 1c, 1d (four of them in FIG. 1), the conductors M1, M2, M3 are electrically connected between the respective magnets to bring a series circuit 3 into conduction that causes an electric current Is to flow, whereby an electric signal (voltage) Vs(=V) indicating the detection of the conductors M1, M2, M3 is output.

Abstract: In a lubricant application system, a prescribed volume of lubricant is transferred from a lubricant discharge port (8) of a prescribed liquid volume discharge device to a rolling element (703) of a rolling bearing (700) in a state in which the lubricant discharge port (8) is positioned directly above and sufficiently close to the rolling element (703), whereby the lubricant is applied to the interior of the rolling bearing (700). Further, the application system inspects whether or not a prescribed volume of lubricant is injected from the discharge device for injecting a lubricant into the interior of a rolling bearing (700).

Abstract: A system and method for monitoring the composition of a magnetically permeable material, where the system comprises a first container containing a volume of magnetically permeable material; a flow path for flowing the magnetically permeable material out of the container; a sensor for determining the inductance of the magnetically permeable material; and a sensor for determining the density of the magnetically permeable material. The sensors for determining the density and inductance of the magnetically permeable material are flow connected to the flow path.

Abstract: An engine oil contamination sensor includes a first sensing electrode and a second sensing electrode. A sensing area is established between the electrodes. The sensor is oriented in an oil pan such that the sensing are is completely submerged in engine oil. A microprocessor is connected to the sensing electrodes and includes a program for determining whether antifreeze is dispersed in the engine oil.

Abstract: A combined oil quality and fuel contamination sensing system includes a capacitive dielectric sensor and pressure sensing arrangements for measuring the dielectric constant of the oil and the pressure of the oil, respectively, with the oil pressure being indicative of oil viscosity and contamination. The sensors take measurements as oil flows through an internal combustion engine and provide an indication of the cause of a problem with oil in an engine. The system may also include a microcomputer and circuitry for generating an indication of dielectric constant and circuitry for generating an indication of the presence of contaminants within the engine. The system may also include an additional sensor measuring the temperature of oil within the system to adjust oil dielectric constant and viscosity indications. The capacitive dielectric sensor constitute the principal restriction in the flow path between an input high pressure sensing port and an outlet low pressure port.

Abstract: A chip-detector assembly has a housing and a probe. The probe is adapted to be coupled to the housing. The chip-detector assembly also includes a locking mechanism comprising a locking ring and a sleeve member. The locking ring is fixedly coupled the housing, and includes a plurality of elongated tangs arranged circumferentially around the ring. The sleeve member is fixedly coupled to the probe, and includes a plurality of contact surfaces that form an outer circumference of the sleeve member. The tangs engage the sleeve-member contact surfaces when the probe is coupled to the housing. The engagement of the tangs and the contact surfaces inhibits the probe from disengaging from the housing once the probe and the housing are coupled.

Abstract: A sensor for detecting particles in a fluid including a housing having a cavity associated therewith, a magnet disposed adjacent the cavity to attract particles into the cavity, first and second coils wound around the outer surface of the cavity, the induction of the first coil being responsive to the particle accumulation within the cavity, the inductance of the second coil being responsive to the temperature of the fluid and being independent of the particle accumulation within the cavity, a first microprocessor coupled to the first and second coils for processing the signals received therefrom and for outputting signals indicative of the particle accumulation within the cavity, an rf transmitter for converting the signals received from the first microprocessor into rf signals, and an rf antenna for transmitting the processed signals to a remote location. The signals outputted from the first microprocessor are encoded with an identification code to identify and distinguish such signals.

Abstract: A bearing-sensor integration in which one or more multi-sensor lubrication sensing devices are positioned relative to the bearing to sense in situ certain parameters of the lubricating fluid. The lubrication sensing devices may be positioned on an interior surface of a bearing raceway (i.e, the outer raceway and/or the inner raceway), the bearing's cage, sealing cover, circulating system, a compliant structure positioned within the bearing chamber, a flowgate, and/or a reservoir. The lubrication sensing device(s) may include sensors for measuring certain parameters of the lubricating fluid, such as pH, chemical characteristics, electrical conductivity, temperature and/or viscosity. A processor receives lubrication-related data from the lubrication sensing device(s), processes the lubrication-related data, and provides information relating to lubrication health and/or health of the machine employing the lubricant.

Abstract: A sensor apparatus for detecting both ferrous and non-ferrous particles in a fluid including a housing adapted for insertion into a fluid line, the housing having a collection cavity formed therewithin for trapping and holding metallic particles which are suspended in the fluid as the fluid passes through the sensor. A first coil wound below the collection cavity and a second coil wound about the collection cavity, the inductance of the first coil being responsive to the temperature of the fluid passing through the sensor and the inductance of the second coil being responsive to the ferrous and non-ferrous particle accumulation within the collection cavity. An electromagnetic coil is spaced above the second coil to attract ferrous particles away from the vicinity of the second coil.

Abstract: A chip detector includes a probe having a locking portion and a housing that receives the probe. The housing comprises two lugs. The lugs engage a corresponding pair of slots defined in the locking portion when the probe is fully inserted in the housing. In particular, a first contact surface on the locking portion abuts a first sidewall on the lug when the probe is fully inserted, thereby securely coupling the probe to the housing. A second contact surface on the locking portion abuts a second sidewall on the lug when the probe is fully inserted, thus preventing the probe from rotating in relation to the housing.

Abstract: A multi-element fluid sensor system for determining the health state of a fluid. The sensor system includes at least two sensors for collecting data relating to a particular parameter (e.g., pH, temperature, conductivity, chemistry, viscosity) of the fluid. The at least two sensors may be integrated onto a semiconductor base so as to provide for a micro sensor for in situ monitoring of the fluid. The system also includes a data fusion processor operatively coupled to the at least two sensors. The data fusion processor processes the fluid data to at least compensate for information fragmentation attributed to using the at least two sensors. The data fusion processor may condense the data, combine the data, evaluate the data and interpret the data.

Abstract: The present invention includes a method of detecting contamination in a fluid sample includes bringing a fluid sample into contact with a pair of spaced apart electrodes and applying a plurality of voltages across the electrodes, wherein the plurality of voltages vary in magnitude between a first and second voltage level. The current is then measured between the electrodes at the plurality of voltages and a contamination level is determined using the measured currents. The present invention also includes a system for determining a particulate contamination level in a fluid sample. The system includes a sensor including a pair of spaced apart electrodes, wherein the fluid sample is brought into contact with the electrodes for detection of the level of particulate contamination therein, and a voltage application means for applying a voltage across the spaced apart electrodes. The system also further includes a current sensor coupled to one of the electrodes.

Abstract: A fluid contamination analyzer employs one or more micro-miniature sensors which provide for a substantial reduction in sensor dimensions form prior art dimensions of approximately 2 in.×2 in. to approximately 1 mm×1 mm. The sensors are incorporated into probes for easy lubricant fluid accessibility or alternatively may be employed in an on-line analyzer residing in the fluid flow path. The sensors sense an impedance of the fluid which is a function of its contamination and communicates the impedance to analysis circuitry via either a hard-wired or RF data link. An array of sensors may also be utilized in conjunction with a magnetic field intensity gradient to obtain a particulate distribution across the array. Impedance information, which is indicative of the particulate distribution, is communicated to analysis circuitry individually or in a multiplexed format for fluid contamination analysis.

Abstract: A monitor for detecting overheating of a critical component in a combustion turbine is provided. The monitor, when used in conjunction with a closed-loop cooling system, comprises a coating comprising an indicator material having an activation temperature. The coating is situated on the internal cooling passages of the critical component. The monitor further comprises a sensor connected to an outlet conduit of the cooling system for determining the amount of degradation of indicator material by monitoring the cooling fluid flowing through the outlet conduit. Embodiments further comprising "sniffer" tubes for use with open-loop air cooling systems also are provided.

Abstract: A device for detecting water leakage and preventing flooding from a water-utilizing appliance connected to water supply lines with water hoses, comprising a main electric unit which attaches to a power line. The main electric unit includes outlets, into which the power cords of the water-utilizing appliance are plugged, and a plurality of water sensor strips extending from the main electric unit for detecting the presence of water. The water leakage detection and flood prevention device further comprises solenoid-actuated cut-off valves connected between the water supply lines and the water hoses of the water-utilizing appliance. When a water leak is detected by the water sensor strips, a circuit breaker within the main electric unit shuts off, cutting power to the outlets and the solenoid-actuated cut-off valve, thereby disconnecting the water supply and electric power to the water-utilizing appliance in order to prevent a flood.

Abstract: A traffic-control sign that automatically displays a primary message, such as "STOP", when electrical power is absent, and an optional secondary message, such as "We Arrest Drunk Drivers", when electrical power is present. The motorless sign is continually encompassed by an enclosure having a transparent facade. A plurality of pivotally-mounted louver panels arranged in a louvered fashion are viewable through the transparent facade. A linkage rod interconnecting the panels provides for unison rotation of the panels. The linkage rod communicates with a solenoid so that the panels assume two distinct positions dependent on the state of the solenoid. These distinct positions reveal primary and secondary viewing surfaces to which the respective messages are affixed. Panel travel approximating 180 degrees allows the messages to be displayed on the overall viewing surfaces formed by the combined individual panel surfaces.

Abstract: A sensor is provided with a conductive sensing element that has a composition adapted to provide a resistance large enough that predetermined magnitudes of voltage noise do not create a false indication of removal, e.g. by abrasion or corrosion. Also, the sensing element composition is adapted to provide a temperature coefficient of resistivity small enough that measurements are substantially independent of temperature. Resistance is preferably greater than 10 ohms and the absolute value of TCR is preferably less than 1000 parts per million per .degree. C. The conductive sensing element may be formed from several materials, including alloys of palladium or lead, particularly palladium-gold, lead-bismuth, or lead-palladium. A combination sensor is provided that includes an abrasion sensing element and a corrosion sensing element on the same substrate.

Abstract: A high-sensitivity capacitive oil deterioration and level sensor includes a conductive housing member with an inner surface defining a ground electrode and conductive inner member with an outer surface defining a measuring electrode. The housing member is adapted to provide a fluidic connection between an oil container and a gap between the ground electrode and the measuring electrode. The sensor also includes electronics adapted to employ this capacitor geometry to generate signals indicative of a degree of deterioration and a level of the oil within the gap.

Abstract: A chip detector assembly includes a body member with a cylindrical passage for receipt of a chip detector. The chip detector includes a triangular flange which cooperates with a congruent triangular window in the housing to permit the chip detector to engage and lock to the housing in any one of three equally spaced, distinct positions.

Abstract: An apparatus for the detection and identification of metal particles, coolant or water in engine oil or hydraulic fluid. The apparatus comprising means for generating a high frequency oscillating field within the fluid, means for generating an electric field within the fluid, means for measuring the real and imaginary part of the complex impedance associated with the interaction of the electric field and the fluid, and means for determining at least one of the presence, the absence or the variation of metal particles, coolant or water in the fluid based upon the impedance measured. The high frequency oscillating field has a frequency range of approximately 2 megahertz to 10 gigahertz. Also, apparatus for the detection and characteristic identification of contaminants in engine oil or hydraulic fluid is provided.

Abstract: A lubricating/hydraulic fluid condition monitor in which a coaxial microwave resonator is placed in a fluid conduit to determine changes in the chemical properties and debris concentration is disclosed. Microwave radiation is applied to the resonator for measuring the resonant frequency and resonator Q. An externally powered electric or magnetic field is used to alternately align and misalign debris in the fluid while the resonator properties are being measured. A logic unit automatically generates tables of resonant frequency and Q versus resonator mode and external field strength. This set of tables constitutes a fingerprint of the fluid condition. By matching the fingerprint against a set of fingerprints taken under known conditions, the condition of the fluid is determined.