Abstract: A trenchduct (10) having an adjustable lid-supporting means (30, 40), the trenchduct (10) having either a bottom (14) or bottomless. The construction consists of metal side walls (12) each having an outward extending flange (18), adjuster bolts (22) mounted vertically upon the horizontally extending flanges (18), and galvanized steel Z-bar side members (30) having threaded openings (37) receiving the adjuster bolts (22) to support the Z-bar side members (30) in abutting relationship with vertical members (16) of the side walls (12). Aluminum side member extrusions (40) having diagonally opposed longitudinally extending slots (42, 43) are positioned upon and secured to the inwardly projecting flanges (34) of the Z-bar side members (30).

Abstract: An earthquake-proof structure is supported on a foundation comprising a plurality of spaced supports, each including a holder having spherical support members mounted thereon to support the structure. The members are preferably mounted in a cage and guide means are provided for reciprocally mounting the holder to guide vertical movements thereof. In addition, a cushioning system is preferably provided on the holder to resiliently cushion and restrain horizontal movements of the rollers.

Abstract: Fire-resistant expansion joint apparatus of a type having opposed base connectors secured to movable structures defining an expansion void therebetween, and a fire barrier assembly slidingly maintained between said base connectors with a saturated adsorbent contained within the barrier assembly that releases coolant liquid by a wicking process into cooling chambers formed within said base connectors during application of high heat condition.

Abstract: A structural log-like member for use in constructing walls, having an outer wooden wall and an inner wooden wall. Wooden spacer members connect the inner and outer walls together in spaced-apart parallel fashion. The spaces between the walls and spacer members can be filled with an insulation material. In use, the structural members can be stacked one on top of the other to form a wall.

Abstract: An apparatus and process for placement of prefabricated buildings at onsite foundations, by providing a plurality of prefabricated foundation piers secured to individual concrete footings via bolting or the like. Foundation piers would be spaced apart in order to accommodate the length of the trailer or the like, in pairs, the distance apart substantially equal to the double spanning beams along the length of the trailer. There is further provided an angle iron collar positioned on the first and last pairs of piers, for securing wooden or the like tracks spanning the entire length of the piers, with the tracks attached to the angle iron collar on the first and last set of piers via screwing or the like. There is further provided a single length of angle iron secured to the track, preferably on the inside of each track, to serve as a guide means in the utilization of the track.

Abstract: A construction element comprises a ribbed sheet metal core whose ribs are of trapezoidal cross section, at least partially embedded in plastic foam. Fretwork extends along the tops of the ribs, transversely or longitudinally thereof. Transversely, the fretwork can be spaced metal straps or wooden slats. Longitudinally, the fretwork can be undulant or twisted metal strips. The fretwork can be embedded in the plastic foam, or can disposed outside and spaced from the plastic foam so as to serve to improve the connection between the construction element and a layer of concrete cast thereon. The construction elements have overlapping edges of reduced thickness into which the metal core extends. The ends of the construction elements have Z-shaped members one wing of which is secured to the core and the other wing of which serves to secure the element to a support.

Abstract: In a roof or wall structure comprising ablong plates having lateral edge portions in the form of partially open cylindrical flanges and in which a flange of one plate is snap locked over a flange of an adjacent plate there is provided rigid beams having at each lateral edge a flange which flanges are snap locked to cylindrical flanges of adjacent oblong plates.

Abstract: A case sealing machine, wherein the position of cases moving through the machine is continuously monitored by a programmable controller that uses information about case position to control the operation of various flap folding and glue applying mechanisms, is disclosed. Cases are moved through the machine by a chain-driven flight bar conveyor mechanism. Case entry is prevented by a raised gate until the flight bar conveyor mechanism is synchronized. Thereafter, the gate is lowered and a power roller feeds the case into the machine. After entering the machine, a case is pushed through the machine by the flight bar conveyor mechanism. The programmable case sealing machine can be programmed to seal the top and/or bottom of the case. If the bottom is to be sealed, the bottom major flaps of the case are separated from the bottom minor flaps by a T-deck mechanism as the case enters the machine. If the bottom of the case was previously sealed, the T-deck is rendered inoperative by the program.

Abstract: The equipment of the present invention is one used in preparation of confectionary, cakes and other sweets of western and oriental fashion as well as of the Japanese fashion. Regardless of whether the viscosity of the materials is high or low, they can be disposed of in the manner of becoming easy to handle. When to bake them, they, in the state of raw material or contents, are wrapped in a heat-resistant film, which, rolled back, is continuously fed. Thus, if the raw material is baked into a desired product, its process is sanitary and efficient, and that inexpensive.

Abstract: Wrapping fragile or easily collapsible articles in foil, for example, aluminium foil by feeding the articles in succession along a track or slideway, forming a tube of foil about the articles, twisting the leading article and its surrounding foil about the main axis of the tube and severing the tube at the twist.

Abstract: A method and apparatus for forming and sealing bags in a continuous or intermittent manner where the bags can be filled during the forming operation. Specifically, there is disclosed an apparatus for supplying a sheet or film of bag material to a mechanism for forming the sheet into a tube having overlapping edges in a longitudinal direction. A series of plates are arranged in the forming apparatus for applying adhesive in spaced lines or strips on opposed surfaces of the overlapping edges. After the adhesive is applied in this manner the opposed surfaces of the overlapped edges are pressed together to seal the edges. The tube is sealed in a transverse direction at the bottom, filled in a conventional manner, sealed in a transverse direction at the top, and then cut to form the bag filled with food or other material, ready for distribution and sale.

Abstract: An automated bag filling machine particularly adapted to handle reclosable fastener strip profile-type plastic bags fed into the machine in a bag chain employs stations for opening, filling, reclosing, and separating filled and closed bags from the remainder of the chain. The drive means for conveying the chain through the filling mechanism include stroke control devices which enable the operation of the machine to be changed over for handling bags of different width sizes. Means are also provided for automatically preventing the bags in the chain from excessively over traveling their proper registration points with the various work stations.

Abstract: A form-and-fill packaging machine has a separator-folder at the cross-over for separating the web edges and folding one edge to form a fin seal in the back of the packaging tube. The separator-former is of one-piece construction generally U-shaped in section with an anti-friction surface. It reduces the effects of the friction of touching web surfaces and maintains direct control of the folding edge.

Abstract: An apparatus and method for continuous rotary ultrasonic sealing of form and fill machines to produce packages utilizes a rotary anvil and cutter knife and an ultrasonic horn having adjustable simulated rotary motion movable in synchronism with the anvil for providing an end seal on packages.

Abstract: Cigarette cartons 12 fed in by conveyor 13 are stacked in a group 14 and then laterally displaced by pusher 26 onto a turntable 27. A further pusher 29 then inserts the group into an awaiting, open ended shipping container 10 or 11, either with or without a 90.degree. turntable rotation depending upon the type of packaging being performed.

Abstract: A combine grain loss monitor system includes sensors adjacent the discharge ends of straw walkers and the upper sieve or chaffer of a cleaning shoe. The shoe sensor is carried in an assembly which is easily mounted on and dismounted from the chaffer without the use of tools. The mounting of the straw walker sensor includes a shield which protects the rear edge and underside of the sensor from damage by flying particles of grain and other material. Both mountings include a baffle designed so as to deflect grain onto the sensor working surface without snagging or holding longer pieces of material such as straw and husks.

Abstract: This invention provides a radio opaque fibre comprising polypropylene, a coupling agent and 55% to 70% of barium sulphate. The coupling agent is preferably isopropyl triisostearoyl titanate. The fibre finds particular application in manufacture of surgical swabs and dressings.

Abstract: A device for the uniform retrieval of yarn ends in an air spinning device. A suction force gradient is created between the air jet nozzle and the waste suction pipe. Gravitational force and the suction gradient cause broken yarn ends to drop from the air jet nozzle orifice toward the waste suction pipe. When yarn piecing is desired, a piecing suction pipe retrieves the yarn end from the nozzle orifice.

Abstract: A large cylindrical baler with a gauge for indicating the relative diameters of a bale being formed in the bale-forming chamber at two axially-spaced points on the bale periphery. The baler comprises a bale-forming chamber defined in part by a conveyor comprised of a plurality of endless loop belts. A belt-tensioning and take-up mechanism tensions all of the belts responsive to the diameter of the largest diameter portion of the bale during formation. The gauge has a pair of feelers engaging two of the belts in engagement with the periphery of the bale at two remote, axially-spaced points on the bale periphery. An indicator is positioned remotely of the bale-forming chamber and is interconnected with the pair of feelers through a signal transmitting means for transmitting a signal to the indicator responsive to the variation in tension of the two belts.

Abstract: In a turbine engine having a compressor with a bleed valve and a variable geometry apparatus is responsive to an operational control member for regulating the flow rate of fuel supplied the turbine engine as a function of atmospheric pressure and the temperature of air supplied to the compressor corresponding to movement of a power lever by an operator to a desired operation of the turbine engine. The power lever has an indicator member fluidically connected to a follower member linked to the operational control member. The fluidic connection is responsive to operational parameters of the turbine engine and limits the rotational input to the follower member when the rate of fuel flow could cause stalling and the development of an unacceptable operating temperature or overspeed condition in the turbine engine.

Abstract: A fuel control method for a gas turbine based on a digital computer. A control system for fuel control, an acceleration control system, an exhaust gas temperature control system, a speed (governor) control system, and a start-up control system are graded in the preference order of fuel control. When a negative feedback signal exceeds a target value in the respective control systems, the fuel control signal is selected in accordance with the grading of the preference order. Of the four control systems, the acceleration and exhaust gas temperature control systems are set to be of the first grade of the preference order and are subjected to an override fuel control preferentially to the other control systems.

Abstract: A gas generator for passing pressurized liquid monopropellants therethrough or causing exothermic decomposition of the monopropellants. A porous catalytic metal plate is used as the degeneration bed. The monopropellant decomposes exothermically upon contact with the catalytic plate. The porosity is obtained by making the plate from an alloy of the catalyst metal and one other metal, the other metal is then etched away by an acid that does not attack the catalyst metal. The porosity is controlled by the amount of other metal used. Surface areas of several hundred times the original plate surface area are obtainable. The mechanical characteristics of the metal plate allow for greater design flexibility than was available with decomposition beds made of refractory material.

Abstract: A system for utilizing exhaust heat and the like from an internal combustion engine, in which at least a part of the internal combustion engine is immersed in a heat transfer medium contained in a vessel provided at the top thereof with an opening. The internal combustion engine is supported by a member secured to the opening of the vessel, an anti-vibration member or members are interposed between the member and the vessel and/or an anti-vibration casing covering the support member is provided, thereby facilitating the anti-vibration and sound arresting measures.

Abstract: A control system has two fixed-displacement pumps for supplying pressurized fluid to a pair of steering cylinders via a steering valve and to a pair of implement cylinders via an implement valve. Connected next to the pumps is a demand valve which is pilot operated to deliver to the steering cylinder pair the pressurized fluid from only one pump upon slight displacement of the steering valve and the pressurized fluid from both pumps upon greater displacement of the steering valve. The demand valve is further pilot operated to deliver to the implement cylinder pair the pressurized fluid from only one pump when the implement valve is actuated in a direction to lower the implement assembly, and the pressurized fluid from both pumps when the implement valve is actuated in a direction to raise the implement assembly.

Abstract: A supercharging pressure control device for mixture-compressing internal combustion engines comprises a bypass valve in a bypass conduit circumventing exhaust gas turbine. A regulating unit of the bypass valve is acted upon by supercharging pressure in an opening direction and by an actuator connected downstream of a throttle valve in the closing direction. The actuator contains a pressure limiting valve and, in parallel thereto, a check valve.

Abstract: A combustor system for use with a turbocharged combustion engine comprises a combustor connected for continuous passage of engine exhaust gases. The combustor includes a relatively low pressure fuel injection system for atomizing fuel for combustion in a substantially vitiated atmosphere, and a fuel control system for supplying fuel to the combustor in response to engine operating conditions.

Abstract: A turbocharger, supercharger or like apparatus for delivering pressurized airflow to an engine, with a housing and valve structure associated with the compressor for permitting selective recirculating flow from the high pressure compressor exhaust to the inlet thereof. A diaphragm acts both as the valve and to define a signal chamber.

Abstract: A vacuum retaining arrangement for retaining a vacuum within a condenser of a steam power plant during a short term outage or shutdown. At least a portion of a turbine gland packing near the condenser, with respect to a sealing steam supply portion, is connected and communicated with an air extractor through a gland condenser. The sealing steam which would otherwise flow into the condenser from the turbine gland package is suctioned or extracted from the gland packing into the gland condenser and the air extractor during the short term outage or shutdown so as to prevent the sealing steam from leaking into the condenser.

Abstract: An air cooled vacuum producing condenser is disclosed for condensing vapors containing non-condensible gases, i.e. air. The condenser includes a condenser chamber with a bundle of condenser tubes across the chamber. Inlet and outlet headers are disposed at opposite ends of the chamber. Water is directed downwardly onto the bundle of condenser tubes, and air is discharged from the interior of the chamber to create a downward flow of air through the chamber across the bundle of condenser tubes.

Abstract: Apparatus for separating ice from concentrated liquid and washing the ice, including a vessel having a bottom and vertical wall joined to the bottom; a plurality of vertical tubular members in the vessel extending upwardly from the bottom; perforations in the upper portion of the tubular members through which concentrated liquid in the vessel can drain into the tubes; a first conduit for feeding a slurry of ice and concentrated liquid to the vessel; a second conduit communicating with the tubes for withdrawing concentrated liquid from the tubes; a concentrated liquid withdrawal third conduit communicating with the vessel lower interior portion for withdrawing concentrated liquid from the vessel; and control means to maintain a predetermined concentrated liquid level, and a predetermined pressure distribution, in the vessel.

Abstract: There is disclosed a heat pump water heater with supplemental heat supply wherein the heat pump is turned on when water has cooled below a predetermined temperature, and is turned off when the water has been heated to a predetermined temperature. In the event frost begins to form on the surface of the heat pump evaporator, the heat pump is turned off and the supplemental heat supply turned on automatically. This condition prevails until the water has been heated to a predetermined temperature, at which time the supplemental heat supply is turned off.

Abstract: A heat transfer system is disclosed in which heat is transferrable to a first primary user by means of a two-coil heat exchanger acting as a condenser which is in the high pressure path, while at the same time another two-coil heat exchanger used as a condenser is used to provide cooling to a record primary user. The system also includes a fan type heat exchanger, which acts as the condenser, when the first primary user does not need heating energy. The system is also operable to heat the second primary user whose heat exchanger acts as a condenser, connectible in series with the heat exchanger of the first primary user.

Abstract: The disclosed invention is an energy conservation system for heating and ventilating structures, particularly buildings with large refrigeration units such as convenience stores, grocery stores and restaurants. The system employs a plurality of manifold assemblies in conjunction with existing air conditioning and heating units to control air flow to recover heat from external heat exchangers of refrigeration units or provide interior ventilation with exterior air. The manifold assemblies preferably employ either a flexible damper gate sliding along tracks on a pivoted gate damper to control air flow.

Abstract: An environmental control system for controlling the environmental conditions in a swimming pool hall 1 comprises a heat pump having a multi-section evaporator 8, compressors 23a and 23b and a multi-section condensor 18.In the day-time, the dry bulb temperature in the pool hall is maintained by circulating space air through a duct 3 to the evaporator 8 where the latent heat is recovered from the moisture laden air. This heat is rejected via the condensor 18 either to the now drier recirculated air or fresh air from an inlet 13 or a mixture of air from the two sources. In a night mode of operation, circulation of space air through the duct 3 is prevented and instead it is recirculated via a direct recirculation duct 53 and is heated by the condensor 18, the heat used to do this being recovered from outside air inducted into the evaporator 8 via an inlet 50.

Abstract: A refrigerating apparatus including a refrigerant circuit constituted by a compressor, a condenser, a first expansion device, a gas-liquid separator, a second expansion device and an evaporator which are successively connected. An injection path interconnects an upper part of the gas-liquid separator and a cylinder of the compressor during the compression stroke thereof. An auxiliary path is formed by connecting a solenoid valve closed in the normal operation and an auxiliary expansion device, with the auxiliary path being provided between the gas-liquid separator and the evaporator so as to be parallel to the second expansion device, and connected to the gas-liquid separator at a position higher than the connecting position of the second expansion device to the gas-liquid separator. The solenoid valve is opened when the load on the refrigerating apparatus increases.

Abstract: A heat-pump type air conditioning apparatus comprising a compressor, a condenser, a throttle member, and an evaporator, which constitute a refrigerant circulation circuit, and an unloading circuit is connected to the compressor to carry out a load reduction control. The air conditioning apparatus further comprises a detector for detecting load condition applied on the compressor and generating a signal representing the detected load condition, and a detector for detecting a condition of a power source for driving the compressor and generating a signal relating to the detected condition of the power source. A control unit is operatively connected to the detectors for controlling the switching of the air conditioning apparatus from a normal, full-capacity operation to a controlled, reduced capacity operation or vice versa in accordance with the signals regarding the detected load and the detected condition of the power source.

Abstract: An aircraft cabin air conditioning system with an air mixing/water separation manifold providing accelerated mixing and attendant removal of water droplets, ice and snow so as to save fuel and to reduce maintenance requirements through lowering the temperature and reducing the supply rate of fresh input ventilation/pressurization air with make-ups of ventilation air requirements met by recirculation of cabin air through the manifold where such mixing and water removal occurs.

Abstract: An apparatus for continuous direct treatment of products by means of a fluid cooling medium comprises a chamber adapted to permit passage of the products. According to the invention this chamber is provided in its bottom plane with two slots spaced from each other in the direction of movement, to which slots the fluid cooling medium is adapted to be supplied in such a way that curtains will be formed at the slots, said curtains defining, together with sidewalls arranged on the sides of the bottom plane, a liquid bed formed of the fluid cooling medium on the bottom plane. The conveying means for the product consists of a perforate endless conveyor belt adapted to travel along the bottom plane of the chamber for moving the product through the liquid bed in order to effect the direct treatment of the product by means of the fluid cooling medium.

Abstract: An insulated modular cooler comprising in one embodiment a plurality of tubular housing sections and a plurality of tubular hollow-walled insert housings containing a refrigerant in the hollow walls of the insert housings. The tubular housing sections can be secured end to end to form an elongated tubular body into which the tubular insert housings are slidably received. The cooler further comprises a top end cap adapted to engage the top of the tubular cooler body as well as the top of each individual cooler housing sections, and a lower end cap adapted to engage the bottom of the tubular body as well as the bottom of each individual cooler housing section. Other embodiments are described in which the inserts are integral with the housing sections, in which several inserts are slidably receivable in a single housing section and in which a single insert is slidably received in each modular housing section.

Abstract: A fastener for the stud of an ornament for pierced ears includes a gripping member and a latch. The gripping member has a base portion, an aperture means in the base portion through which a stud can pass, and two resilient arms. The first resilient arm is affixed to the base portion such that it can flex to move toward the stud when the latter is positioned through said aperture, and the second resilient arm is also affixed to the base in opposed relation to the first arm, so that it can flex and move toward the first arm. The arms can contact a stud on opposite sides thereof and squeeze it, and the squeezing force is enhanced and secured by a latch which is pivotally connected to the first arm and is adapted to engage the second arm, in order to draw the two arms toward each other, thus squeezing a stud positioned between them.

Abstract: A method and setting for mounting ornamental beads and gems which avoids the use of claws. The setting is comprised of a flat planar sheet metal support with an aperture therein and a rectilinear strip that extends diametrically across the aperture. The strip has two ends, both of which are initially in one piece with the support. In keeping with the method of this invention, one of said ends of the strip is sheared from the support adjacent a side of the aperture. The strip is then deformable about its non-sheared end from a position coplanar with the aperture thereby enabling the threading of an ornamental bead or gem with a straight-through opening therein onto said strip. Subsequent to threading of the ornament on the strip, the strip is positioned in the plane of the aperture and is held in this position by frictional wedging of the sheared end of the strip against the portion of the support from which that end has been sheared.

Abstract: A high pressure steamer for continuous wet-heat treatment of a cloth has an inlet and an outlet for taking a cloth continuously in and out of the steamer body. The cloth inlet has an inlet side seal mechanism provided with a liquid seal tank and the cloth outlet has an outlet side seal mechanism provided with a slow cooling tank. A plurality of liquid application tanks and prewashing tanks are provided in the steamer for boiling the cloth passing through the steamer intermittently and repeatedly. A filter is provided for cleansing waste water exhausted from the slow cooling tank. A heat exchanger is provided for heating cleansed water by the use of high temperature waste liquor from the prewashing tank, and conduits supply the heated water to the liquid application tanks and prewashing tanks.

Abstract: The invention discloses a process of forging a sprocket segment for a track-type vehicle undercarriage. The forging process produces sprocket segments that conform to very restrictive tolerances without the necessity of additional machining or finishing.The process includes heating a metal billet (5') in an electric furnace (60), rough-shaping the billet (5'), then forging the billet (5') in a die (62) to form a sprocket segment (5) having a size and shape substantially equal to the desired finished shape of the segment (51). The forged sprocket segment (5) is trimmed and then placed in a coining die (8) wherein at least two nonparallel surfaces (A,B,C) are formed to a desired finished dimension.The invention also includes an apparatus (8) for forging a sprocket segment to a desired finished dimension. The apparatus (8) includes an upper die member (80), a lower die member (8'), and a transversely-moveable die member (82).

Abstract: A light weight heavy duty blind rivet setting tool having one piece upper housing containing a rivet setting mechanism and a one piece lower pressure vessel having an air activated piston operable to pressurize a medium in the upper housing to activate the rivet setting mechanism. The upper housing has a handle area containing a trigger which, through a trigger linkage, operates a valve on the bottom of the pressure vessel which is connectable to an air source. A muffler is positioned adjacent the valve to receive the exhausted air from the pressure vessel after the tool has been operated, to minimize the noise level of the tool operation. The trigger linkage is adjustable to eliminate the tolerance stack-up in the linkage.

Abstract: An automatic torque wrench testing machine uses a strain-gauge transducer to develop signals corresponding to the torque applied to the wrench. The machine is driven by pneumatic/hydraulic drive under the control of a microprocessor. Torque is initially applied at a relatively high rate but as the value of the torque sensed approaches that of a target value, the applied torque is automatically reduced to relatively low rate. When the target or click value is reached, the signal produced by the transducer drops sharply from its highest value. Thereafter, a predetermined number of additional torque values are sensed and compared with the highest value. If none of the succeeding values exceed the highest value, the highest value is displayed, and the direction in which torque is applied to the wrench is reversed until a neutral position is reached. The torque drive is then stopped. The wrench is then tested in the opposite direction.

Abstract: A device for applying imbalance to a rotor comprises a plurality of chambers disposed symmetrically around the rotor. Each has an opening and is adapted to contain a fluid. Each of a plurality of opening devices associated with the chambers is operable under remote control so as to open the opening of the associated chamber, so that the fluid contained in it may be evacuated from it. Each opening device comprises a pyrotechnic valve incorporating a piston rigidly attached to an assembly and movable from a first position in which the assembly closes the opening of the associated chamber to a second position in which the assembly opens the opening. Such movement is obtained in response to firing of the pyrotechnic valve. The opening device also includes a control circuit which incorporates a receiver responsive to a signal transmitted from a fixed source with no material transmission medium. This control circuit fires the pyrotechnic valve.

Abstract: A testing device for a flowmeter arranged in a pipe, has a bypass conduit connected with the pipe in which the flowmeter is arranged, a gauge container arranged in said bypass conduit and selectively connectable in series with the pipe, an element for selectively connecting said gauge container in series with the pipe, a measuring piston displaceable under the action of a fluid which flows into said gauge container over a measuring section having a beginning and an end, start and stop switches arranged at the beginning and at the end of the measuring section, respectively, and operative for starting and stopping of addition of electric impulses from the flowmeter during displacement of said measuring piston, a device for comparing the impulses being added with a gauge volume of the measuring section, and a measuring cylinder located in the interior of the gauge container, the measuring cylinder forming the measuring section and carrying the start and stop switches and the measuring piston, said gauge containe

Abstract: A solvent dumping apparatus is described having an inlet enclosure coupled to the inlet of a detector and an outlet enclosure coupled to the outlet of a detector. Venting means are provided for both enclosures, one of which is controllable; means are provided for introducing sample gas into the inlet enclosure; and means are provided for introducing gas into the outlet enclosure. During a detection mode, at least one of the venting means is so adjusted as to cause sample gas to flow through the detector and out the venting means for the outlet enclosure, and during a diversionary mode, at least one of the venting means is so adjusted as to cause the gas introduced into the outlet enclosure to pass back through the detector and carry any sample gas out through the venting means for the inlet enclosure. In preferred forms of the invention, one of the venting means is a back pressure regulator.

Abstract: A high-speed dynamic porosimeter including a device for removing accumulated debris is disclosed. The porosimeter has an apertured surface, preferably curved, across which a web whose porosity is to be measured is drawn while suction is applied to the apertures. A pressure transducer monitors the pressure in a sensor line or chamber, which pressure varies as a function of the porosity of the web. A scraper blade scrapes debris from the apertured surface from time to time. Preferably, vacuum suction is also applied to a slot at the upstream side of the apertured surface to ensure a good seal between the web and the surface.

Abstract: An apparatus and method for measuring the air leakage rate of a structure, such as a building, for the purpose of assessing the need to add caulking, weatherstripping or the like to the building to minimize energy loss. The equipment includes a panel which may conveniently fit into a doorway or window frame of the building and seal the same against air leakage except for an air pathway passing through the panel. The pathway has a fan or the like for causing air to flow through the pathway, preferably from the inside to the outside to create a partial vacuum inside the building. Pressure sensors are provided to measure the partial vacuum and the air pressure inside the air pathway. From these measurements and a knowledge of the total internal volume of the building structure, the air leakage rate of the structure can be determined and expressed, for example, as a number of total volume changes per hour. The apparatus is portable and can be used for almost any building without structural modification.