Abstract: A nondestructive evaluation method for determining the material used in a below ground service line includes inserting a probe with a wave measurement device therein into an area corresponding to a location of a service line; inciting a service line wave through an exposed portion of the service using a vibratory shaker; measuring, by the wave measurement device, a substrate wave created by the service line wave passing thought the service line and into the substrate; identifying, by a data acquisition system, the service line wave velocity; comparing the service line wave velocity to a known set of wave velocities in service line according to a service line material; and identifying the service line material in the service line by comparing the wave velocity in the service line with the known set of wave velocities.

Abstract: A nondestructive evaluation method for determining the material used in a below ground service line includes inserting a probe with a wave measurement device therein into an area corresponding to a location of a service line; inciting a service line wave through an exposed portion of the service using a vibratory shaker; measuring, by the wave measurement device, a substrate wave created by the service line wave passing thought the service line and into the substrate; identifying, by a data acquisition system, the service line wave velocity; comparing the service line wave velocity to a known set of wave velocities in service line according to a service line material; and identifying the service line material in the service line by comparing the wave velocity in the service line with the known set of wave velocities.

Abstract: An oxygen sensor arrangement is arranged to sense the oxygen in a breathing loop of a breathing apparatus. The sensor arrangement comprises at least one primary oxygen sensor arranged to operatively measure the oxygen in the breathing loop, and a control arrangement for obtaining measures from the oxygen sensor. A test channel arrangement is adapted to operatively provide a first gas having a first fraction of oxygen from a first supply to the primary oxygen sensor at a position adjacent to or directly adjacent to the primary oxygen sensor. A first test valve arrangement is arranged to operatively open and close the flow of the first gas through the test channel arrangement. The control arrangement is arranged to operatively actuate the first test valve arrangement so as to provide an amount of the first gas to the primary oxygen sensor via the test channel arrangement.

Abstract: The invention is directed to an oxygen sensor arrangement 8 for sensing the oxygen in a breathing loop 29 of a breathing apparatus 100. The sensor arrangement 8 comprises at least one primary oxygen sensor 30 arranged to operatively measure the oxygen in the breathing loop 29, and a control arrangement 40 for obtaining measures from said oxygen sensor. A test channel arrangement 15, 362 is adapted to operatively provide a first gas having a first fraction of oxygen from a first supply 20 to said primary oxygen sensor 30 at a position 267 adjacent to or directly adjacent to said primary oxygen sensor. A first test valve arrangement 41 is arranged to operatively open and close the flow of said first gas through said test channel arrangement 15, 362. Said a control arrangement 40 is arranged to operatively actuate said first test valve arrangement 41 so as to provide an amount of said first gas to said primary oxygen sensor 30 via said test channel arrangement 15, 362.

Abstract: A soil specimen rests on a porous support. The support may be a porous ceramic plate or other body, for instance rated at 15 bar (1,500 kPa) or greater. The plate overlies a reservoir full of water that hydraulically contacts either an elastic membrane, that is fitted with a strain gauge, or a pressure transducer. As the soil specimen dries out, water is drawn from the pore space, which decreases the amount of water surrounding the soil particles, causing an increase in the pore water tension. The tension draws water from the saturated plate and reservoir, causing a change in the output of the strain gauge or pressure transducer. The tension is transduced by the strain gauge or pressure transducer, and is continuously recorded. The entire apparatus described above may rest on a balance. As the soil dries out, and its mass is reduced, the change in mass can be measured, and from the change, the mass of the remaining soil and water can be determined.