1. A transducer assembly, comprising:
a housing;
a sealing diaphragm;
a removable diaphragm radially constrained to the housing;
a piezoelectric crystal disposed within the removable diaphragm; and
a sleeve;
wherein the sealing diaphragm is located at an end of the sleeve;
wherein the removable diaphragm and at least a portion of the housing are disposed within the sleeve; and
wherein the removable diaphragm is biased towards the sealing diaphragm.
2. The transducer assembly of claim 1, wherein the sleeve comprises a threaded portion.
3. The transducer assembly of claim 1, further comprising a biasing mechanism disposed about the housing to bias the removable diaphragm towards the sealing diaphragm.
4. The housing assembly of claim 3, wherein the biasing mechanism is radially constrained to the housing.
5. The transducer assembly of claim 1, wherein the transducer assembly is configured to be disposed on a spool piece.
6. The transducer assembly of claim 1, further comprising:
a sealing element disposed about the housing, wherein the sealing element provides a seal between the sleeve and the housing.
7. The transducer assembly of claim 5, further comprising:
a sealing element disposed about the sealing diaphragm, wherein the sealing element provides a seal between the sealing diaphragm and the spool piece.
8. The transducer assembly of claim 1, wherein the piezoelectric crystal is secured to the removable diaphragm with an adhesive.
9. The transducer assembly of claim 1, wherein the transducer assembly is intrinsically safe.
10. The transducer assembly of claim 1, wherein the transducer assembly is zone 0 certified.
11. A spool piece used to measure flow of a fluid, the spool piece comprising:
a transducer assembly disposed on the spool piece,
wherein the transducer assembly comprises:
a housing at least partially disposed within a wall of the spool piece;
a sealing diaphragm disposed within the wall of the spool piece;
a removable diaphragm radially constrained to the housing and disposed within the wall of the spool piece;
a piezoelectric crystal disposed on the removable diaphragm; and
a sleeve;
wherein the removable diaphragm is disposed within the sleeve;
wherein at least a portion of the housing is disposed within the sleeve; and
wherein the removable diaphragm is biased towards the sealing diaphragm.
12. The spool piece of claim 11, wherein the sleeve threadedly engages with the spool piece.
13. The spool piece of claim 11, further comprising a biasing mechanism disposed about the housing to bias the removable diaphragm towards the sealing diaphragm.
14. A method of replacing a transducer assembly from a spool piece, the method comprising:
providing the transducer assembly having a housing, a removable diaphragm, a sleeve with the removable diaphragm and at least a portion of the housing disposed within the sleeve, a sealing diaphragm located at an end of the sleeve, and a biasing mechanism disposed about the housing and biasing the removable diaphragm towards the sealing diaphragm;
removing the housing and the removable diaphragm from an opening of the spool piece; and
preventing fluid from escaping within the spool piece with the sealing diaphragm while the housing and the removable diaphragm are removed from the opening of the spool piece.
15. The method of claim 14, wherein a piezoelectric crystal is disposed within the removable diaphragm.
16. The method of claim 14, further comprising:
replacing the removable diaphragm; and
inserting the housing and the removable diaphragm into the opening of the spool piece.
17. The method of claim 14, wherein the sleeve comprises a threaded portion and threadedly engages with the spool piece.
18. The method of claim 14, wherein the biasing mechanism is radially constrained to the housing.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A powerline communication transmission module for transmitting a signal over a three-line electrical mains supply comprising:
at least two coupling transformers, each transformer for coupling the signal to first and second line-pairs of a three-line electrical mains supply, the first and second line-pairs different from one another;
driving circuitry for driving a first version of the signal over the first line-pair, and for driving a second version of the signal over the second line-pair; and
at least one inversion circuit for selectively causing one version of the signal to be inverted relative to the other version of the signal prior to transmission, dependent upon an enacted transmission mode.
2. The powerline communication transmission module of claim 1, wherein a line common to both the first and second line-pairs of the mains electrical supply lines comprises an Earth or Ground line.
3. The powerline communication transmission module of claim 1, wherein in a first transmission mode:
the inversion circuitry is operable to process the first and second versions of the signal so they are non-inverted relative to one another; and
the driving circuitry is operable so that the first and second versions of the signal are not inverted relative to the other with the signal transmitted as a differential-mode signal on both line-pairs simultaneously.
4. The powerline communication transmission module of claim 1, wherein in a second transmission mode:
the inversion circuitry is operable to invert one of the first and second versions of the signal relative to the other; and
the driving circuitry is operable to transmit the first and second versions of the signal as a common-mode signal on both line-pairs.
5. The powerline communication transmission module of claim 1, further comprising gain circuitry operable to vary the signal gain of one or both of the first and second versions of the signal.
6. The powerline communication transmission module of claim 5, wherein the gain circuitry comprises line driving circuitry.
7. The powerline communication transmission module of claim 5, wherein the gain circuitry comprises a digital to analog converter having variable gain.
8. The powerline communication transmission module of claim 5, wherein the gain circuitry is operable to transmit the signal repeatedly at a plurality of different relative gain settings so as to determine a best gain for transmission.
9. The powerline communication transmission module of claim 1, wherein the transmission circuitry is operable to transmit the signal repeatedly using a plurality of modes to determine a best performing transmission mode.
10. The powerline communication transmission module of claim 1, further comprising reception circuitry having a switch network and operable to support reception of incoming signals on multiple combinations of line-pairs of the three-line electrical mains supply.
11. The powerline communication transmission module of claim 10, wherein the transmission module is operable to receive incoming signals on each combination of line-pairs to determine a best performing line-pair combination.
12. The powerline communication transmission module of claim 10, wherein the switch network comprises a plurality of selectable resistances in each reception path.
13. The powerline communication transmission module of claim 10, further comprising a table of preferable transmission andor reception settings for at least some of the other nodes of a network in which it forms a node.
14. A method for operating a powerline communication transmission module to transmit a signal over a three-line electrical mains supply, the method comprising:
coupling the signal to first and second line-pairs of a three-line electrical mains supply via at least two coupling transformers, the first and second line-pairs different from one another;
driving a first version of the signal on the first line-pair;
driving a second version of the signal on the second line-pair; and
selectively inverting one version of the signal relative to the other version of the signal prior to transmission, dependent upon an enacted transmission mode.
15. The method of claim 14, further comprising, in a first transmission mode, transmitting the first and second versions of the signal on both line-pairs simultaneously such that they are not inverted relative to one another as a differential-mode signal.
16. The method of claim 14, further comprising, in a second transmission mode:
inverting one of the first and second versions of the signal relative to the other; and
transmitting the first and second versions of the signal as a common-mode signal on both line-pairs simultaneously.
17. The method of claim 14, further comprising varying the signal gain of one or both of the first and second versions of the signal.
18. The method of claim 14, further comprising transmitting the signal repeatedly at a plurality of different relative gain settings so as to determine a best gain for transmission.
19. The method of claim 14, further comprising transmitting the signal repeatedly using a plurality of modes to determine a best performing transmission mode.
20. The method of claim 14, further comprising receiving incoming signals on multiple combinations of line-pairs of the three-line electrical mains supply.
21. The method of claim 20, further comprising receiving incoming signals on each combination of line-pairs to determine a best performing line-pair combination.