Pressure transducer

A pressure transducer comprising:

• a base;
• an elastic magnetic film on the base;
• a magnetic core base;
• a ring shaped magnetic core having a ring-like channel mounted to the core base;
• a coil in the ring-like channel of the magnetic core;
• the core base being mounted to the base and a gap being formed between the elastic magnetic film and magnetic core;
• a condenser;
• an FM (frequency modulation) circuit means electrically connected to the coil and condenser so that when the elastic magnetic film deforms through pressure application, a corresponding change of inductance of the coil results causing the FM circuit means to produce an output signal whose frequency changes so that by testing the change of frequency, a change of the value of the pressure applied can be obtained;
• and
• on said base a piston type ring-like film front cover means being mounted for adapting the transducer for soil pressure testing.

A pressure transducer comprising:

• a base;
• an elastic magnetic film on the base;
• a magnetic core base;
• a ring shaped magnetic core having a ring-like channel mounted to the core base;
• a coil in the ring-like channel of the magnetic core;
• the core base being mounted to the base and a gap being formed between the elastic film and magnetic core;
• a condenser;
• an FM (frequency modulation) circuit means electrically connected to the coil and condenser so that when the elastic magnetic film deforms through pressure application, a corresponding change of inductance of the coil results causing the FM circuit means to produce an output signal whose frequency changes so that by testing the change of frequency, a change of the value of the pressure applied can be obtained;
• and
• a filtering device means being provided on the base for blocking solid substances for adapting the transducer for liquid pressure testing.

A pressure transducer, comprising:

• a base;
• an elastic magnetic film on the base;
• a magnetic core base;
• a ring shaped magnetic core having a ring-like channel mounted to the core base;
• a coil in the ring-like channel of the magnetic core;
• the core base being mounted to the base and a gap being formed between the elastic magnetic film and magnetic core;
• a condenser;
• a FM (frequency modulation) circuit means electrically connected to the coil and condenser so that when the elastic magnetic film deforms through pressure application, a corresponding change of inductance of the coil results causing the FM circuit means to produce an output signal whose frequency changes so that by testing the change of frequency, a change of the value of the pressure applied can be obtained;
• and
• the elastic magnetic film being a high elastic ferrite alloy material.

A pressure transducer, comprising:

• a base having a central aperture therein, and a relatively smaller diameter aperture in a floor of the central aperture and at an end of which opposite the floor an elastic magnetic film is mounted;
• a magnetic core base engageable in the central aperture;
• a magnetic core mounted to the magnetic core base;
• a coil associated with the magnetic core;
• a gap formed between the core and the elastic magnetic film;
• spacing means for adjusting said gap between the core and film;
• and
• FM circuit means electrically connected to the coil for detecting a change of inductance of the coil as a result of pressure applied to the elastic magnetic film.

A method for manufacturing a pressure transducer, comprising the steps of:

• providing a sensing element formed of an inner base, an elastic magnetic film mounted across an aperture in the inner base, and a core base containing a core and coil mounted within the inner base such that a gap is formed between the core and the elastic magnetic film;
• providing an outer base having an aperture in which the inner base is received;
• painting threads in the outer base aperture with a sealant and then threading the sensing element inner base into the aperture of the outer base such that it is sealed there;
• providing a piston type front cover which receives the outer base and sensing element, a cavity being formed between the outer base and inner base and the piston-type front cover;
• vacuumizing the cavity and filling it with oil;
• providing in the outer base a filling aperture in communication with the cavity and filling the cavity with the oil through the filling aperture;
• sealing the filling aperture;
• providing a condenser and an FM circuit device, placing them in at least one aperture in the outer base, and sealing them there;
• placing a back cover over the outer base which mates with the front cover;
• and
• applying a waterproof layer over the front and back covers.

A method for manufacturing a pressure transducer comprising the steps of:

• providng a sensing element formed of a base, an elastic magnetic film mounted across an aperture in the base, and a core base containing a core with a coil mounted within the aperture in the base such that a gap is formed between the core and the elastic magnetic film with the core base mounted in the base;
• providing said base with a cavity above the core base;
• providing a filtering device adjacent the elastic film for blocking solid substances;
• providing a condenser and an FM circuit device with a cable, placing them in said base cavity and sealing the cavity by filling it with a sealant;
• after the sealant has solidified, placing a back cover rubber ring and screw member having a hole onto the cable in succession from an end thereof;
• and
• then the back cover is attached to the base above the cavity and the screw member is tightened in an aperture in the back cover.

A pressure transducer, comprising:

• a base having a central aperture passing completely therethrough, and at least one cavity outwardly of the central aperture;
• an elastic magnetic film on the base;
• a magnetic core base;
• a ring shaped magnetic core having a ring-like channel mounted to the core base;
• a coil in the ring-like channel of the magnetic core;
• the core base being mounted to the base in the central aperture and a gap being formed between the elastic magnetic film and magnetic core;
• a condenser;
• and
• an FM (frequency modulation) circuit means received in the outer cavity and electrically connected to the coil and condenser so that when the elastic magnetic film deforms through pressure application, a corresponding change of inductance of the coil results causing the FM circuit means to produce an output signal whose frequency changes so that by testing the change of frequency, a change of the value of the pressure applied can be obtained.

A pressure transducer, comprising:

• a base;
• an elastic magnetic film on the base comprising Ni50W2Al;
• a magnetic core base;
• a ring shaped magnetic core having a ring-like channel mounted to the core base;
• a coil in the ring-like channel of the magnetic core;
• the core base being mounted to the base and a gap being formed between the elastic magnetic film and magnetic core;
• means for adjusting the gap by moving the core base relative to the base;
• a condenser;
• and
• an FM (frequency modulation) circuit means electrically connected to the coil and condenser so that when the elastic magnetic film deforms through pressure application, a corresponding change of inductance of the coil results causing the FM circuit means to produce an output signal whose frequency changes so that by testing the change of frequency, a change of the value of the pressure applied can be obtained.