A differential pressure indicator includes a multi-polar driving magnets train clamped on a piston pin that moves in response to the changes in pressure conditions, thereby driving a multi-polar follower magnet carrying an indicating member, to move across a scale for a total angular range of 90° to 270°. The exact angular displacement of the follower magnet per unit linear displacement of the driving magnets train is decided by varying the relative magnetic strengths of the driving and follower magnets or by varying the spacing between adjacent magnets of the driving magnetic train. Further, magnetic flux of an auxiliary magnet fitted on the piston pin at a 90° orientation relative to the driving magnet train is utilized for actuating a magnetic switch in the switch assembly.

Apparatus for measuring the operating parameters of espresso coffee machines, comprising: a filter-holder body configured to be associated with a water dispensing nozzle of an espresso coffee machine; said body internally defining a chamber for the passage of the water dispensed by said nozzle; a filling element arranged in said chamber and having a cavity for the passage of the water dispensed by the nozzle towards an outlet duct; a water outlet terminal element associated with said filter-holder body downstream of said chamber and defining said water outlet duct; and reading means for the water pressure and temperature values passing from the chamber to the outlet duct; said reading means comprise at least one pressure reading device operatively engaged with said water outlet terminal element and at least one temperature reading device operatively engaged at said cavity obtained in the filling element.

Apparatus for measuring the operating parameters of espresso coffee machines, comprising: a filter-holder body configured to be associated with a water dispensing nozzle of an espresso coffee machine; said body internally defining a chamber for the passage of the water dispensed by said nozzle; a filling element arranged in said chamber and having a cavity for the passage of the water dispensed by the nozzle towards an outlet duct; a water outlet terminal element associated with said filter-holder body downstream of said chamber and defining said water outlet duct; and reading means for the water pressure and temperature values passing from the chamber to the outlet duct; said reading means comprise at least one pressure reading device operatively engaged with said water outlet terminal element and at least one temperature reading device operatively engaged at said cavity obtained in the filling element.

A gauge for a hybrid pressure and flowgauge regulator includes first indicia and second indicia. The first indicia provides an indication of a flow rate of a gas exiting an outlet of the hybrid pressure and flowgauge regulator when the gas exits with a pressure below a gauge threshold pressure. The second indicia provides an indication of the pressure of the gas exiting the outlet of the hybrid pressure and flowgauge regulator when the pressure of the gas exiting the outlet is above the gauge threshold pressure.

A gauge for a hybrid pressure and flowgauge regulator includes first indicia and second indicia. The first indicia provides an indication of a flow rate of a gas exiting an outlet of the hybrid pressure and flowgauge regulator when the gas exits with a pressure below a gauge threshold pressure. The second indicia provides an indication of the pressure of the gas exiting the outlet of the hybrid pressure and flowgauge regulator when the pressure of the gas exiting the outlet is above the gauge threshold pressure.

An air inflation device includes an inflation unit having an air outlet channel extending along a first axis, and an insertion channel extending along a second axis transverse to the first axis and partially communicating with the air outlet channel. A pressure gauge unit is rotatably mounted on the inflation unit and includes a pressure gauge, and a shaft extending outwardly from the pressure gauge and inserted into the air outlet channel. The shaft has an annular groove formed in an outer peripheral surface thereof and corresponding to and communicating with the insertion channel. An air guide unit includes a manifold inserted into the insertion channel and engaging the annular groove.

An air inflation device includes an inflation unit having an air outlet channel extending along a first axis, and an insertion channel extending along a second axis transverse to the first axis and partially communicating with the air outlet channel. A pressure gauge unit is rotatably mounted on the inflation unit and includes a pressure gauge, and a shaft extending outwardly from the pressure gauge and inserted into the air outlet channel. The shaft has an annular groove formed in an outer peripheral surface thereof and corresponding to and communicating with the insertion channel. An air guide unit includes a manifold inserted into the insertion channel and engaging the annular groove.

A depth selector or current depth provider for use by a variable speed air system. As a depth selector it is preferably in the form of a rotary switch on the user interface for the air system. The rotary switch can have 3 positions for maximum depth selections, such as, without limitation 15, 25, and 65 feet. Other depth values and number of depth selections provided can be used and all are considered within the scope of the disclosure. A microcontroller of the system reads the voltage from the voltage divider created by the rotary switch selection to determine which position the rotary switch is in. The microcontroller uses this information to set the upper and lower pressure limits for the dive.

A depth selector or current depth provider for use by a variable speed air system. As a depth selector it is preferably in the form of a rotary switch on the user interface for the air system. The rotary switch can have 3 positions for maximum depth selections, such as, without limitation 15, 25, and 65 feet. Other depth values and number of depth selections provided can be used and all are considered within the scope of the disclosure. A microcontroller of the system reads the voltage from the voltage divider created by the rotary switch selection to determine which position the rotary switch is in. The microcontroller uses this information to set the upper and lower pressure limits for the dive.

A measuring system for detecting pressure and/or density, having at least one process connector, a diaphragm, a measuring unit, a housing and a display, wherein a process pressure acts via the process connector on the diaphragm and the measuring unit converts a stroke of the diaphragm caused thereby into a rotational movement of a pointer when the process pressure is changed via the measuring unit, and the pointer on the display shows the pressure applied on the diaphragm on a scale. The measuring system includes a connecting piece which includes the process connector, a meter base and a tubular extension.