356 results about "Differential pressure" patented technology

The invention discloses a pressure-controlled drainage gas production method and system for a coal-bed gas well. The pressure-controlled drainage gas production method comprises the steps that drainage is conducted through the first daily drainage amount, wherein the first daily drainage amount meets the eliminating demand for production interference objects in a coal bed; and a pressure-supplementing medium is injected while drainage is conducted, and the downhole flow pressure daily drop amount is maintained as a first differential pressure value so as to avoid retracting and closing of pores and cracks in the coal bed. According to the pressure-controlled drainage gas production method for the coal-bed gas well, the drainage speed at the drainage state can be conveniently determined, the eliminating demands for drilling and completion fluids, pulverized coal and slack coal in the coal bed can be met, and meanwhile, retracting and closing of the pores and the cracks in the coal bed can also be avoided; and compared with the prior art, the pressure-controlled drainage gas production method is simple in process, the production efficiency of the coal-bed gas well can be greatly improved, and quite high practical value and popularization value are achieved.

The invention discloses a flowmeter-oriented embedded multi-parameter fusion calibration control method and system, relates to the technical field of industrial measurement and embedded control, and is used for solving the problem of unstable calibration caused by misalignment of multi-link flow signals, compensation lag and fusion oscillation. The method relates to synchronous acquisition, pretreatment and calibration of differential pressure type, ultrasonic wave and thermal type mass measurement links and environment parameters such as temperature, pressure and density. All-channel unified time scales are established through ternary binding, filtering and denoising, zero snapshot and alignment rules, a stability scoring mechanism is constructed in combination with offset behavior recognition, event classification and feature aggregation, and dynamic switching of a compensation path and a fusion strategy is driven. In a double-path fusion structure, table look-up compensation, model estimation, multi-algorithm parallelism and fusion track recording are adopted, version traceability and calibration result closed-loop control are achieved, and the stability and rechecking performance of mass flow output under complex disturbance are effectively improved.

The invention discloses a fixed-point calibration and precision compensation method of a differential pressure type flowmeter and related equipment, and relates to the field of fluid measurement, and the method comprises the following steps: connecting the differential pressure type flowmeter to be calibrated and a standard flowmeter in series in the same gas path, and respectively collecting front-end pressure, front-back pressure difference of a laminar flow element and gas temperature; and a volume flow calculation model is established based on the structure parameters of the laminar flow element. Under the condition that a standard flowmeter outputs constant flow, fixed-point calibration is conducted on the flowmeter at a plurality of discrete temperature nodes and a plurality of discrete pressure nodes, a temperature compensation factor and a pressure compensation factor are determined respectively, and a continuous temperature compensation function and a continuous pressure compensation function are constructed through B-spline curve fitting. And substituting the compensation function into a volume flow calculation model to form a compensation volume flow model, and correcting the output of the differential pressure type flowmeter. And the influence of temperature change and pressure change on the flow characteristics and geometric characteristics of the laminar flow element can be effectively eliminated.

The invention relates to the technical field of equipment compensation control, and discloses a medical suction device with an altitude compensation function and a control method thereof. The method comprises the following steps: reading ambient air pressure data of a first pressure sensor, reading molecular sieve tank differential pressure data of a second pressure sensor, collecting pressure data of an output end of a third pressure sensor, and determining a real-time altitude according to the ambient air pressure data; a breathing pressure fluctuation value is calculated based on the molecular sieve tank differential pressure data, when the breathing pressure fluctuation value is lower than a preset negative pressure threshold value, the current breathing frequency is recorded, and nitrogen removal time, pressure equalizing time and flushing time are determined to control an electromagnetic valve to work; and when the oxygen concentration is lower than a first concentration threshold value and the real-time altitude height is lower than a preset height, increasing the nitrogen removal time by a first preset proportion and increasing the target rotating speed by a second preset proportion, and when the oxygen concentration is lower than a second concentration threshold value, stopping the operation of the compressor and closing all the electromagnetic valves. According to the invention, the false alarm rate is effectively reduced, and the equipment safety is improved.

The invention relates to a DDPF regeneration control method, system and program product based on a differential pressure transducer, when a vehicle is in a parking regeneration control state, an engine is controlled to increase the idle speed, and when the upstream temperature of the DDPF exceeds an ignition temperature limit value, the vehicle enters the parking regeneration state; during regeneration, the amount of fuel injected into the engine is determined according to the DDPF upstream temperature, the set temperature target value and the waste gas amount, and engine rear injection is controlled for DDPF regeneration; according to the method, the pressure difference between an inlet and an outlet of the DDPF is obtained, the peak pressure difference P of the DDPF is determined when the regeneration state continues till the pressure difference begins to drop, and the fuel injection quantity is corrected or a prompt signal is sent out according to the size relation between the P and a set limiting value. A temperature sensor at the rear end of the DDPF is omitted, the characteristic that the pressure difference is increased and then reduced due to oxidation heat release of carbon particles and hydrocarbon during regeneration is utilized, regeneration control is achieved based on a pressure difference sensor, and the risk of local overheating damage is dealt with by comparing a pressure difference peak value with a set limiting value.

The invention provides a mixed flow velocity and flow measuring device and method, and particularly relates to the technical field of measuring instruments, and the device comprises a gas mixing assembly, a flow field optimization assembly, a flow velocity sensing assembly and a signal processing assembly. The gas mixing assembly comprises a differential channel mixer and a mixing cavity, and gas premixing is achieved. The flow field optimization assembly comprises a plurality of air duct partition plates and straight pipe sections, and the mixed gas conveying pipeline is divided into a plurality of independent divided air ducts; the flow velocity sensing assembly comprises a rectification assembly and a pressure sensing assembly, the rectification assembly comprises a pore plate and / or a grid, and the pressure sensing assembly comprises a plurality of uniformly distributed pressure sensing elements; the signal processing assembly comprises a differential pressure sensing transmitter, a static pressure sensing transmitter, a temperature sensing transmitter, an atmospheric pressure sensing transmitter and a data processing module. The pressure sensing element detects differential pressure signals, the differential pressure sensing transmitter converts the signals, the data processing module calculates the average flow velocity and flow of the mixed gas based on the signals and measurement data, and the measurement precision and accuracy are improved.

The present application belongs to the field of smelting coal gas recovery, and particularly relates to an optimized control method and system for combustible gas recovery. The method divides the smelting process into N measurement time periods, and calculates the average secondary combustion coefficient of each time period in real time. Meanwhile, M target smelting time zones and their weights are set, and a dynamic target value sequence is established. Based on the initial fan speed, the measured coefficient is adjusted through multiple iterations of the furnace, and when the measured coefficient is greater than the target value, the speed is reduced in steps, and a thermal imager and a differential pressure instrument are introduced to monitor the smoke emission. A smoke emission rate statistics and tolerance threshold judgment mechanism is established to trigger speed backtracking adjustment, and finally the average secondary combustion coefficient of each time period is minimized to generate an optimal fan speed model. The present application maximizes the improvement of the calorific value of coal gas and the recovery of carbon monoxide under the premise of preventing smoke from the furnace mouth.

The invention belongs to the technical field of gas field water flow meter measurement, and particularly discloses a two-phase flow measuring device and method resistant to oil and gas field water corrosion. The device is used for measuring gas field water in a pipeline and is matched with a flow totalizer. Comprising a first differential pressure flowmeter used for measuring the mass flow of gas in a pipeline, a second differential pressure flowmeter used for measuring the mass flow of liquid in the pipeline, a temperature sensor used for measuring the temperature of the gas in the pipeline, and a liquid level differential pressure transmitter used for measuring the liquid level in the pipeline. The temperature sensor, the first differential pressure flow meter, the second differential pressure flow meter and the liquid level differential pressure transmitter are respectively connected with the flow totalizer. According to the invention, the problems of gas and liquid two-phase flow measurement, accurate sulfur-containing gas field water measurement and the like can be solved under the condition that gas field water components contain corrosive (especially sulfur-containing components), non-full pipe flow and liquid phase flow velocity.

The invention relates to the technical field of fan control, and discloses a fan rotating speed adjusting method and system based on a dynamic pollution load. The method comprises the following steps: collecting a target PM2.5 concentration, a target VOC concentration and a target microorganism concentration of each monitoring point, and calculating a comprehensive pollution load index of each monitoring point; traversing boundary critical points in all the monitoring points based on the comprehensive pollution load index and generating a boundary identification vector; the real-time pressure drop of the air inlet side and the air outlet side of the filter element in each fan is collected, and the pressure difference compensation gain is calculated; calculating a target reference rotating speed for all monitoring points in the responsible sector of each fan; and calculating the average pollution load index of the responsible sector of each fan, executing fuzzy reasoning to obtain a rotating speed increment, and generating a PWM duty ratio according to the target reference rotating speed and the rotating speed increment to drive each fan. The technical problems of space pollution response lag and energy consumption imbalance are solved, and the performance of the air purification system is improved.

The invention relates to the technical field of chemical equipment, in particular to a special online density precision detector for a full-automatic chlorination process. The device comprises an instrument desk assembly installed on a reaction kettle, a compressed air inlet pipe used for air inlet is connected to the side of the instrument desk assembly, an air inlet main valve and a pressure reducing valve are arranged on the compressed air inlet pipe, a rotor flow meter is arranged in the instrument desk assembly, the bottom end of the instrument desk assembly is connected with an H air blowing pipe and an L air blowing pipe, and the two air blowing pipes are both connected into the reaction kettle. The bottom end of the L-shaped air blowing pipe is higher than the bottom end of the H-shaped air blowing pipe, a pressure difference transmitter is arranged on the top of the instrument desk assembly, and the L-shaped air blowing pipe and the H-shaped air blowing pipe are sleeved with sampling pipes. Through the arrangement of the sampling pipe, it is ensured that the measurement environment is stable, and the measurement precision is ensured; the direct contact between an instrument and reaction liquid is directly avoided, indirect measurement is carried out by adopting pressure difference, the service life of equipment is greatly prolonged, and the device is suitable for production of various highly corrosive materials.

The application relates to the technical field of sealing performance detection, and discloses a detection system and a detection method for detecting bidirectional leakage of a spherical sealing valve of an aircraft bleed air system; the system comprises an air inlet device, a sealing device and a detection device; the air inlet device provides pressure-controllable and clean test gas; the sealing device is used for fixing the spherical sealing valve and simulating two sealing states of the spherical sealing valve in a high-pressure stage regulator, thereby forming two independent test gas paths; the detection device is connected to the outlet of the sealing device and is used for quantitatively or qualitatively detecting leakage gas and comprises a flow monitoring unit and a differential pressure monitoring unit; the sealing device can test the sealing performance of a ceramic ball and a poppet valve seat and the sealing performance of the ceramic ball and a valve mounting seat by replacing or adjusting a limiting structure; the application realizes component-level bidirectional sealing performance detection, improves test precision and maintenance efficiency, can identify defects before assembly, and reduces the rework rate.

The application provides a double-side opening cabin type negative pressure air gun source and a firing method thereof, and belongs to the field of marine seismic exploration.The application comprises two upper and lower symmetrical firing units on the basis of the existing negative pressure air gun source and the single-side negative pressure air gun source, the firing cabin is surrounded by the firing cabin housings of the two firing units, each firing unit comprises a pushing cabin and a returning cabin, the pushing cabin is in a high pressure state, the returning cabin is in a vacuum state, the differential pressure makes the firing unit realize the effect of rapid opening of the cabin, and the implosion energy can be fully released.In addition, the two firing units of the application are synchronously fired, the opening speed can be further improved, the stress during the opening process is uniform, and the shaking of the cabin body is reduced.The double-side opening cabin mode can improve the consistency of the wavelet and improve the quality of the seismic data.

The application relates to the technical field of ball valves, in particular to a large-pressure-difference-operated half-ball valve, which comprises a valve body, flanges are fixedly connected to two ends of the valve body, an upper pressure cover is fixedly connected in communication with the top of the valve body, an upper actuator is fixedly connected to the top of the upper pressure cover, and a lower shaft sleeve is fixedly connected in communication with the bottom of the valve body; through the design of staged pressure reduction and step-by-step opening and closing, the actuator load is significantly reduced, the service life of the valve is prolonged, and the manufacturing cost is reduced; specifically, channel two is first opened to balance the pressure of the upstream and downstream, then channel one is opened, the staged pressure reduction is realized, the medium force required to be overcome by the actuator is greatly reduced, meanwhile, double actuators are adopted to replace a single actuator, two small-torque actuators are used to control two valve cores, the total cost is much lower than that of a single large-torque actuator, and two valve seat rings are independently arranged, bidirectional sealing is realized by matching corresponding half spheres and O-shaped small ball valve cores, and the sealing reliability is effectively improved.

The application provides a high-static-pressure differential pressure gauge convenient to assemble, and belongs to the field of differential pressure gauges, to solve the problem that impurities in the delivered liquid or gas cannot be conveniently filtered and collected, and comprises a gauge body and a connecting pipe, the connecting pipe is installed on the gauge body, a spring is fixedly connected in a rotating disc, the other end of the spring is fixedly connected with a limiting plate, and the limiting plate is fixedly connected with a clamping block. The application is provided with a treatment box; when the connecting pipe is used to deliver liquid or gas, the liquid or gas passes through the treatment box, the residual impurities can be filtered and collected through the internally-installed filter screen, and the adaptability of the gauge body is avoided from being affected by the impurities; when the filter screen needs to be cleaned, the rotating rod can be rotated to drive the first bevel gear to rotate, the first bevel gear can drive the threaded rod to rotate through the second bevel gear, the threaded rod drives the extrusion box to move inward through the moving plate, the extrusion box is separated from the positioning plate, and after being unobstructed, the extrusion box can be taken out for subsequent cleaning and use.

This invention relates to the field of construction monitoring equipment technology, specifically a settlement observation instrument for roadbed safety construction. The instrument includes a string strain gauge and a differential pressure static level. The differential pressure static level has connecting pipes on both its air and water inlets, which are fixed to a conduit support. The signal line of the string strain gauge is fixed within the conduit support. The two ends of the string strain gauge are fixed to a fixed end and a floating end, respectively. The floating end includes a movable end seat fixedly fitted onto one end of the string strain gauge. This invention allows adjustment of the floating end's height position through a sliding fit between the upper ball joint and the rotating sleeve. The orientation and tilt angle of the floating end can be freely adjusted through the universal joint between the upper ball joint and the upper spherical shell, and between the lower ball joint and the lower spherical shell. During on-site installation, adjusting the floating end position ensures that the string strain gauge's measuring rod remains in a natural, unloaded, and unstressed state, thus avoiding measurement errors introduced by initial stress and effectively improving the accuracy and stability of roadbed settlement and tilt monitoring.

The invention discloses an integrated double-hole friction stress sensor based on pressure gradient detection, and belongs to the field of friction sensors. The sensor adopts flow field surface pressure to detect the magnitude of friction stress, and a friction pressure sensitive module, a pressure detection module and a friction calculation module are integrated in the sensor. When the pressure sensing double-hole structure is subjected to an incoming flow effect, the wall surface has a pressure gradient due to friction resistance, the differential pressure is amplified through the double-hole structure, the differential pressure and the static pressure are detected through the high-precision differential pressure sensitive core body and the high-precision absolute pressure sensitive core body, and then the friction resistance stress is solved. The sensitive core body adopts an integrated packaging scheme, and a double-hole sensitive structure, a pressure cavity, an absolute pressure sensitive core body, a differential pressure sensitive core body and a detection circuit module can be integrally packaged in a single tube shell, so that application under a high static pressure background is realized. The friction resistance stress sensor is excellent in performance, compact in structure, high in robustness and capable of achieving friction resistance stress detection of the hypersonic flight vehicle under the extreme working condition.

This invention provides a low-temperature flow resistance testing device for microchannel radiators, comprising a control device and a testing device. The control device includes a temperature environment chamber, an electric valve, a manual valve, a filter, a check valve, and a computer. The testing device includes a temperature sensor, a pressure transmitter, and a differential pressure transmitter. This invention enables the testing of microchannel radiators under various low-temperature conditions, automatically adjusting the liquid coolant flow rate and inlet temperature according to set requirements during the testing process. This invention eliminates the drawbacks of manual control of various parameters, simultaneously satisfying low-temperature flow resistance testing under various conditions, thus improving the accuracy and efficiency of the test.

The utility model provides a mounting structure of an oxygen supply assembly and an oxygen generator. The mounting structure of the oxygen supply assembly comprises a cavity, and an atmospheric pressure cavity, a circuit board and an oxygen spraying valve which are arranged in the cavity, the circuit board is provided with a differential pressure type respiration sensor and an oxygen storage tank pressure sensor, the atmospheric pressure cavity is communicated with the atmosphere, and a valve seat of the oxygen spraying valve is provided with an air inlet used for being connected with an oxygen storage tank, an oxygen supply port used for supplying oxygen to the outside and a tank pressure monitoring port connected with the oxygen storage tank pressure sensor. The respiration sensor interface is connected with the differential pressure type respiration sensor; the differential pressure type respiration sensor is connected with the atmospheric pressure cavity and the respiration sensor connector, the accuracy of the detection result can be improved, the oxygen storage tank pressure sensor can be connected with the oxygen storage tank through the valve seat and detect the oxygen pressure, no hole needs to be additionally formed in the oxygen storage tank, and therefore the integrity of the oxygen storage tank is higher, and the air tightness is better.

To provide a method for flattening a carrier body by suppressing warpage of the carrier body and processing a contact surface of a correction tool into a reverse geometric surface to offset thermal stress.SOLUTION: The device comprises an upper carrier pressing device 10 and a lower carrier pressing device 20, wherein the upper carrier pressing device is provided with a first heater 12, a first sealed space 14 and an air bag 13, the lower carrier pressing device is provided with a second heater 23, a second sealed space 24 and a correction jig 23, a carrier body 30 is disposed between the air bag and the correction jig and is kept at an operating temperature and an operating pressure of the air bag and the correction jig, and a pressure difference formed by the air bag and the correction jig is used to effectively suppress warpage and deformation of the carrier body. In addition, through simulation or actual measurement, the first surface 31 of the carrier is a geometric curved surface, and the upper contact surface of the correction jig is processed into an inverse geometric curved surface to offset the thermal stress and flatten and shape the carrier.SELECTED DRAWING: Figure 1

The invention discloses an air-cooled heat exchange system adaptable to crosswind and a control method thereof.The system comprises an air-cooled heat exchanger, a differential pressure sensor, a fan and two temperature sensors, the fan is arranged on the outer side or the inner side of the air-cooled heat exchanger, and the fan can form a forward working mode or a reverse working mode; the pressure difference sensor detects the air pressure difference between the external environment air pressure outside the outer side of the air-cooled heat exchanger and the air pressure inside the air-cooled heat exchanger, the two temperature sensors detect the temperature of the inlet end and the outlet end of the air-cooled heat exchanger respectively, or one temperature sensor detects the temperature of the outlet end of the air-cooled heat exchanger, and the other temperature sensor detects the temperature inside the air-cooled heat exchanger. The differential pressure sensor, the air-cooled heat exchanger outlet end temperature sensor, the air-cooled heat exchanger inlet end temperature sensor and the fan are electrically connected with the control system. In the control method, the control system controls the fan to work according to the air pressure difference and the temperature difference of the two sensors. According to the invention, the system can run stably when encountering crosswind.

This utility model relates to a differential pressure gauge mounting structure for a static pressure chamber. A differential pressure gauge is installed on the left side of the static pressure chamber shell near the top. The gauge is mounted on a mounting plate, which is then connected to a mounting recess in the static pressure chamber shell via the mounting plate. The gauge dial is mounted on the front side of the mounting plate, and the gauge body passes through a through hole and a rear guide housing before extending into the static pressure chamber shell. Positioning grooves are provided on both sides of the mounting recess, and positioning protrusions matching these grooves are provided on both sides of the rear side of the mounting plate. This utility model first mounts the differential pressure gauge on the mounting plate, then mounts the entire structure onto the static pressure chamber. This ensures timely replacement and maintenance of the gauge regardless of whether the panel has an inspection window.

The utility model discloses a pre-filter detection tool which comprises a first water storage device, a heater, a first test tube, a first booster pump, a first manual valve, a first stop valve, a pre-filter to be detected, a differential pressure gauge, a second test tube, a flow meter, a second water storage device, a third test tube and a second stop valve. A heater is arranged in the first water storage device; the first water storage device, the first test tube, the pre-filter to be tested, the second test tube and the second water storage device are connected in sequence; the first booster pump, the first manual valve and the first stop valve are sequentially arranged on the first test tube from upstream to downstream; the flow meter is arranged on the second test tube; the differential pressure gauge is connected to pipelines at two ends of the pre-filter to be tested; the third test tube is connected in parallel with the test tube between the first manual valve and the flow meter; and the second stop valve is arranged on the third test tube. The tool can be used for completing detection of all items such as purified water flow, pressure drop and rejection rate of the pre-filter, and is simple in structure and easy to control.

The invention provides a high-sulfur natural gas metering and pressure guiding device, method and system, and the device is characterized in that pressure measurement equipment is communicated with a natural gas pipe wall through a first pipeline, the pressure measurement equipment is communicated with differential pressure measurement equipment through a second pipeline, and the differential pressure measurement equipment is connected with the natural gas pipe wall through a third pipeline; the differential pressure type flowmeter is installed in the natural gas pipeline, the second pipeline and the third pipeline are communicated with the pressure liquid accumulation tank through branch pipes respectively, and the liquid inlet ends of the differential pressure liquid accumulation tank, the pressure liquid accumulation tank and the differential pressure liquid accumulation tank are all provided with switch valves electrically connected with the pressure measuring device and the differential pressure measuring device. According to the invention, the state of the gas flow of the natural gas pipeline is firstly judged by the differential pressure type flowmeter, and then pressure and differential pressure detection is carried out on the natural gas in a steady state by the pressure measurement equipment and the differential pressure measurement equipment, so that the accuracy of the detection data is guaranteed, and the corresponding switch valves are opened in time; therefore, the maintenance workload of high-sulfur-content field equipment is reduced.

The application discloses a multiphase fluid flowmeter, which comprises a flowmeter base, at least two pressure sensors and at least one pressure reducing device; the pressure reducing device is arranged in the flowmeter base, and the pressure sensors are arranged at two ends of the pressure reducing device. The flowmeter does not need movable structures such as impellers to calculate flow, so that the flowmeter is simple and exquisite in structure, differential pressure measurement and flow conversion can provide a wider linear region, and the design without movable structures can ensure accuracy and facilitate replacement, so that the flowmeter can not be limited by fluid types and viscosity, and has a wider application range.

This system allows for greater flexibility in the installation location of the differential pressure power generation cooling unit, and the electricity and cooling generated during differential pressure power generation can be used for computational processing in data centers and other facilities where high demand is expected in the future, thereby contributing to energy conservation and decarbonization. [Solution] The control device S performs a cooling quantity tracking calculation allocation control, which allocates the calculation amount to a plurality of calculation processing devices CS1 and CS2 in such a manner that the predicted cooling quantity per unit time during the prediction period, which is generated by calculations performed by the calculation processing devices CS1 and CS2 corresponding to the differential pressure power generation cooling units SEC1 and SEC2, is matched to the predicted cooling quantity per unit time during the prediction period, which is generated by the differential pressure power generation cooling units SEC1 and SEC2, through cooling quantity prediction control.

The application discloses an air loop detection method and system based on a standard table method, and relates to the field of gas flow detection. The method comprises the following steps: collecting temperature, static pressure, humidity and geometric parameters, generating a working condition benchmark and calculating air density; correcting the time scale of differential pressure, temperature and humidity pressure and a reference signal to generate a compensated differential pressure sequence; calculating instantaneous volume flow according to the compensated differential pressure and the air density, updating the Reynolds number, and forming a nominal flow sequence by calling a standard table conversion relationship; reconstructing the cross-sectional velocity distribution based on the geometric parameters, and correcting the flow sequence; generating a robust leakage index through the inter-segment energy relationship and the pressure drop-flow balance, identifying abnormalities and forming an abnormality mask; weighting and removing the flow sequence to finally generate a robust flow sequence and record data, and forming traceable detection information. Through dynamic working condition correction, abnormality identification and data traceability mechanism, the accuracy, reliability and data traceability of the air loop detection are significantly improved.

The invention relates to a system and method for cooling system pump control. A method of controlling a coolant distribution unit is disclosed. The method includes: initiating, by a controller, a pump control mode; measuring, by a sensor, a differential pressure at a filter connected to the pump; determining, by the controller, whether the differential pressure is greater than a first predetermined value; when it is determined that the differential pressure is larger than the first preset value, whether the differential pressure is larger than a second preset value or not is determined, and the second preset value is larger than the first preset value; and generating a first output upon determining that the differential pressure is less than or equal to a second predetermined value.

To provide an improved electronic device for aerosol delivery equipment that can extend the usefulness of the device. [Solution] The aerosol delivery device includes at least one housing, a heating element, a sensor, and a microprocessor coupled to the heating element and the sensor. The at least one housing surrounds a reservoir configured to hold an aerosol precursor composition. The sensor generates a measurement of the differential pressure between the ambient atmospheric pressure and the pressure caused by the airflow through at least a portion of the aerosol delivery device. The sensor also converts the measurement of the differential pressure into a corresponding electrical signal. The microprocessor receives the corresponding electrical signal and operates in active mode only when the differential pressure is at least a threshold differential pressure. In active mode, the microprocessor controls the heating element to activate and vaporize the components of the aerosol precursor composition.

A power take-off device for use in a wave energy converter unit has a power take-off hull connectable to a mooring device and connected to or connectable to the buoy, and a power extracting device connected to the power take-off hull. The power extracting device is adapted to extract power as the buoy moves with the waves, by applying a control force within a predetermined range. The power take-off hull has a first shell movable relatively to a second shell, and the first and second shells together define an inner volume. A seal is provided to separate the inner volume from water outside of the power take-off hull, and the differential pressure between water surrounding the power take-off hull and the inner volume provides a nearly constant pre-tension force from the first and second shells being pushed together by surrounding water pressure.