Embodiments of air admittance valve assembly and plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly to allow or stop a flow for use with enclosed environment includes a housing having, an inlet disposed at a first end of the housing fluidly coupled to environment surrounding housing, an outlet disposed at a second end of housing fluidly coupled to enclosed environment, and an interior volume divided into a first zone, a second zone, and a third zone; a first valve having a first valve seat and a first sealing member urged by an existing force between a closed or open position; and a second valve having a second valve seat and a second sealing member urged by an existing force between a closed or open position.

A microfabricated pressure transducer is formed in a multilayer substrate by etching a plurality of shallow and deep wells into the layers, and then joining these wells with voids formed by anisotropic etching. The voids define a flexible membrane over the substrate which deforms when a force is applied.

A system for indicating the pressure in an aircraft landing gear shock absorber is provided, the system comprising a source of collimated light and a target, the source of collimated light being attached to the aircraft, and being operable to emit light onto the target; the position of the point of incidence of the light emitted from the source of collimated light on the target being indicative of the pressure in the aircraft landing gear shock absorber. A kit for making such a system and a method of indicating the pressure in an aircraft landing gear are also provided.

A system for indicating the pressure in an aircraft landing gear shock absorber is provided, the system comprising a source of collimated light and a target, the source of collimated light being attached to the aircraft, and being operable to emit light onto the target; the position of the point of incidence of the light emitted from the source of collimated light on the target being indicative of the pressure in the aircraft landing gear shock absorber. A kit for making such a system and a method of indicating the pressure in an aircraft landing gear are also provided.

Embodiments of air admittance valve assembly and plumbing system incorporating the same are provided herein. In some embodiments, a valve assembly comprising a housing, a first valve comprising a first valve sealing member and a first valve seat, and a second valve comprising a second valve sealing member and a second valve seat, and a pipe, an inlet, an outlet, a first zone, a second zone, a third zone, the first and second valve sealing member is closed by gravity and open based upon the pressure differential between the first zone, second zone and third zone.

A syringe pump is disclosed that includes a pressure sensor assembly, a plunger, first and second pressure sensors, and a processor. The pressure sensor assembly senses a force and includes the plunger having a sensing surface configured to receive the force, the first pressure sensor operatively coupled to the plunger and configured to estimate the force applied to the sensing surface, and the second pressure sensor operatively coupled to the plunger and configured to estimate the force applied to the sensing surface. The processor is coupled to the first and second pressure sensors to estimate a magnitude of the force.

A syringe pump is disclosed that includes a pressure sensor assembly, a plunger, first and second pressure sensors, and a processor. The pressure sensor assembly senses a force and includes the plunger having a sensing surface configured to receive the force, the first pressure sensor operatively coupled to the plunger and configured to estimate the force applied to the sensing surface, and the second pressure sensor operatively coupled to the plunger and configured to estimate the force applied to the sensing surface. The processor is coupled to the first and second pressure sensors to estimate a magnitude of the force.

A syringe pump is disclosed that includes a body, a syringe seat, a syringe actuator, a memory, and one or more processors. The syringe seat is coupled to the body. The syringe actuator is configured to actuate a syringe secured within the syringe seat. The memory is configured to store a plurality of instructions. The one or more processors, in accordance with the plurality of instructions, is/are configured to: prime the syringe pump in a prime phase; determine if an occlusion exists during the prime phase using a first test; stop the prime phase; initiate fluid delivery into a patient; enter into a start-up phase; determine if an occlusion exists using a second test during the start-up phase; transition from the start-up phase into a steady-state phase; and determine if an occlusion exists during the steady-state phase using a third test.

A syringe pump is disclosed that includes a body, a syringe seat, a syringe actuator, a memory, and one or more processors. The syringe seat is coupled to the body. The syringe actuator is configured to actuate a syringe secured within the syringe seat. The memory is configured to store a plurality of instructions. The one or more processors, in accordance with the plurality of instructions, is/are configured to: prime the syringe pump in a prime phase; determine if an occlusion exists during the prime phase using a first test; stop the prime phase; initiate fluid delivery into a patient; enter into a start-up phase; determine if an occlusion exists using a second test during the start-up phase; transition from the start-up phase into a steady-state phase; and determine if an occlusion exists during the steady-state phase using a third test.

A height adjustable hitch receiver is disclosed and described.