A sensor system is for sensing a substance in a fluid (1), comprising a first sensor (10) and a second sensor (12) of the same type. The first sensor (10) is used until a calibration event, during which the second sensor (12) is used. The second sensor (12) is used only during the calibration event. The first sensor (10) is calibrated using the sensor information from the second sensor (12).

A testing apparatus employs an interface module removably attached to a filter testing device. The interface module includes a first flowpath communicating with an outlet of the testing device and a housing of the filter device, a first valve disposed in the first flowpath, a second flowpath communicating with the housing of the filter device and an exhaust, a second valve disposed in the second flowpath, and an enclosure enclosing the first flowpath, the first valve, the second flowpath, and the second valve. The interface module is cleanable and/or sterilizable, and replaceable. A filter integrity testing method uses an interface module to prevent contamination of the testing device and cross-contamination of different filter devices and avoid liquid ingress into the testing device.

Turbidity measurement systems and methods of using the same are described. A turbidity measurement system comprises a vessel configured to hold a wellbore fluid, wherein a porous media is positioned in the vessel; a light source positioned to direct light at the vessel; a light detector positioned to measure light intensity of light emitted by the light source and passing through the vessel; a backscatter detector configured to measure the light intensity of reflected light emitted from the light source; and a computer system communicatively coupled to at least one of the light source, light detector, or light detector.

A triaxial test apparatus for measuring eroded soil particles under action of seepage force includes a constant-flow seepage system, a soil particle transport grading measurement system, a large-range volume pressure control vacuum system and a data processing and analyzing system, where the constant-flow seepage system is connected to the soil particle transport grading measurement system and the large-range volume pressure control vacuum system by means of pipelines separately, the data processing and analyzing system includes a data acquisition device and a computer, the constant-flow seepage system, the soil particle transport grading measurement system and the large-range volume pressure control vacuum system are connected to the data acquisition device by means of lines separately, and the computer is connected to the data acquisition device by means of a line.

An apparatus adapted to examine a paper web includes a rotatable first bobbin, a rotatable second bobbin, and a first testing device. The first bobbin has a paper we wound thereabout that has transverse bands spaced apart along a length thereof. The second bobbin is arranged to receive the paper web from the first bobbin with a paper web path defined between the first and second bobbins. The first testing device is disposed along the paper web path and is arranged to nondestructively measure a diffusivity of one of the transverse bands of the paper web.

An in-situ hydraulic jet exploiting device and method of a low-permeability natural gas hydrate reservoir. The device includes a high-pressure reaction kettle configured for formation, fracturing and exploiting of a hydrate, a stable-pressure gas supply module configured to adjust and control a gas flow rate, a constant-speed constant-pressure liquid supply module configured to control a liquid flow rate or keep liquid injection pressure constant, a thermostatic water bath configured to provide a constant-temperature environment for a device system, a back-pressure module configured to automatically control an exploiting rate or exploiting pressure, an in-situ hydraulic jet permeability enhancement module, a data collection and processing module configured to collect and process basic system parameters, and a pipeline connecting various components.

A method of integrity testing a porous material is disclosed, providing a porous material suitable for filtration to be tested, said porous material having a first surface and a second surface; wetting said porous material with a wetting liquid; providing a gas stream comprising at least first and second gases humidified with said wetting liquid below the saturation vapor pressure of said wetting liquid and wherein said humidified gas stream has a humidity of 50-99%; introducing said gas stream to said first surface of said porous material; causing said first and second gases to flow through said porous material; measuring the concentration of at least one of said first and second gases in the permeate stream exiting said second surface of said porous material; and comparing the measured concentration to a predetermined concentration.

A date tree waste-based lost circulation material (LCM) is provided. The date tree waste LCM may include includes fibers from the date tree waste produced from processing date trees in the production of date fruits. The date tree waste may include fibers from one or more of the following: date tree trunks, date tree rachis, date tree leaflets, date tree panicles, and date tree roots. The date tree waste LCM may include fibers having lengths in the range of 5 millimeters (5 mm) to 15 mm, diameters in the range of 0.5 mm to 0.8 mm, and having an aspect ratio range of 6 to 30. Methods of lost circulation control using and manufacture of a date tree waste LCM are also provided.

Methods and systems for detecting leakage in a permeability measurement system. The method includes connecting a plurality of flow lines to a first dimension of a core sample assembly, connecting one or more flow lines to a second dimension of the core sample assembly, placing the core sample assembly with the connections in a measurement cell such that the flow lines are accessible from outside of the measurement cell, connecting one or more gas sensors to one end of each of the flow lines, connecting an inlet of the measurement cell to a gas tank, setting fluid pressure inside the measurement cell to a predetermined value, and detecting a leakage in the core sample assembly by the one or more gas sensors coupled to the flow lines.

The present invention relates to method of testing the bacterial filtering efficiency of a fabric, the method including the steps of preparing a solution including bacteria, peptone water and NaCl, feeding said solution including bacteria to a nebulizer, generating an aerosol of said bacterial solution and flowing said solution through a cascade impactor to provide a plurality of bacteria colonies in a plurality of plates present in a plurality of stages of said cascade impactor, characterized in that the concentration of NaCl in the peptone water used to prepare said bacterial solution is in the range of 30 g/L to 150 g/L and in that the temperature of said cascade impactor is in the range of −15° C. to 15° C.