scholarly journals AIR PRESSURE CONTROLLED MASS MEASUREMENT SYSTEM

2013 ◽  
Vol 24 ◽  
pp. 1360002
Author(s):  
RUILIN ZHONG ◽  
JIAN WANG ◽  
CHANGQING CAI ◽  
HONG YAO ◽  
JIN'AN DING ◽  
...  

Mass measurement is influenced by air pressure, temperature, humidity and other facts. In order to reduce the influence, mass laboratory of National Institute of Metrology, China has developed an air pressure controlled mass measurement system. In this system, an automatic mass comparator is installed in an airtight chamber. The Chamber is equipped with a pressure controller and associate valves, thus the air pressure can be changed and stabilized to the pre-set value, the preferred pressure range is from 200 hPa to 1100 hPa. In order to keep the environment inside the chamber stable, the display and control part of the mass comparator are moved outside the chamber, and connected to the mass comparator by feed-throughs. Also a lifting device is designed for this system which can easily lift up the upper part of the chamber, thus weights can be easily put inside the mass comparator. The whole system is put on a marble platform, and the temperature and humidity of the laboratory is very stable. The temperature, humidity, and carbon dioxide content inside the chamber are measured in real time and can be used to get air density. Mass measurement cycle from 1100 hPa to 200 hPa and back to 1100 hPa shows the effective of the system.

Author(s):  
Narciso F. Macia ◽  
Ha Van Nguyen

This paper presents a fluidic device capable of generating electrical micro-power from a steady air pressure source. The Fluidic Driven Piezoelectric Generator (FDPG) relies on a fluidic pressure-controlled oscillator, a fluidic linear proportional amplifier with its output ports connected to its input ports, to convert a steady air pressure into an oscillating air pressure. The piezoelectric device then converts the oscillating air pressure into an AC electrical voltage that is available for rectification and subsequent source of electrical power. This project has demonstrated that the FDPG produces 0.55W of electrical power, with an air pressure supply of 2.0 psig. This translates to an efficiency of 35%. This paper compares the predicted power level output of an analytical model to the proof-of-concept plastic model. The fluidic oscillator model was implemented in an equivalent electrical circuit using PSPICE. This approach has applications in remote or portable pneumatic applications where intelligent instrumentation and control are needed yet no battery or auxiliary electrical power is available to drive an electronic microcontroller.


2011 ◽  
Vol 301-303 ◽  
pp. 147-152
Author(s):  
Xiu Wu Sui ◽  
Xiao Guang Qi ◽  
Da Peng Li ◽  
Guo Xiong Zhang ◽  
Yu Ming Fan

The paper presents the measurement system of the air plane fuel mass consisting of cylinder shell resonating density meter and double cylinders capacitance level meter. The finite element analysis method of ANSYS10.0 is used to analyze the performance of cylinder shell resonator density meter and double cylinders capacitance fuel level sensor. On the base of simulation, the cylinder shell is 45mm in length, 9mm in radius, and 0.08mm in thickness, the material is 3J53; the double cylinders capacitance is 8mm in inside diameter, 23.6mm in outside diameter, and 550 mm in length. The experiments show the uncertainty of cylinder shell resonating density meter is only 0.12%, the uncertainty of double cylinders capacitance level meter is only 0.2%, and the uncertainty of the fuel mass measurement system is 0.4%.


Author(s):  
Achmad Faris Nasyarudin ◽  
Ritzkal Ritzkal ◽  
Arief Goeritno

 The design and construction of a device prototype for a water level measurement system in a tank and controlling a number of garden light analogies has been carried-out and the prototype can be integrated into smarthome system. Three topics are discussed in this paper, including the manufacture, programming, and performance measurement of device prototypes. The formation of prototype of the device is done through wiring integration between electronic devices, in order to obtain the hardware handshacking. Programming the prototype of device is done through the creation of algorithms and preparation of syntax, in order to obtain the software handshacking. The performance of the prototype of device is measured when integrated into the Smarthome system, in order to obtain the hardware and software handshacking. The performance of prototype of the device when monitoring in the form of information about the water level in the water tank with 3 (three) conditions, namely the criteria of "empty", "medium", and "full", while the control in the form of information about the operation of ON/OFF of the LED as an analogy to the lamp garden are done for 3 (three) positions, namely position #1, #2, and #3. The manufactured subsystem prototype can be integrated into the smarthome system when a validation test is performed. Prototype of the device for monitoring and control based-on web that can be integrated into the smarthome system.


PEDIATRICS ◽  
1982 ◽  
Vol 69 (3) ◽  
pp. 351-354
Author(s):  
Clyde G. Smith ◽  
Jack L. Paradise ◽  
Tina I. Young

Tympanograms with peaks located in the high-positive air pressure range (≥ 50 mm H2O) are infrequently recorded in clinical practice and have been little discussed in the literature. Such tympanograms accounted for 1.2% of a series of 8,011 tympanograms recorded at various times from 1,556 subjects ranging in age from 7 months through 12 years. Correlations between otoscopic diagnoses and tympanometric findings in the case of 65 of the high-positive air pressure tympanograms form the basis of the present report. Of the 65 high-positive air pressure tympanograms, 51 showed relatively high compliance (≤5.5 Madsen units), and of these 46 (90%) were associated with ears considered normal otoscopically. Fourteen of the high-positive air pressure tympanograms showed low compliance (>5.5 Madsen units), and of these, six (43%) were associated with ears considered normal, six (43%) with ears showing signs of acute infection, and two (14%) with ears in which the presence of effusion seemed probable. A previously presented zonal schema for classifying tympanograms has been modified on the basis of these findings.


Author(s):  
Takeshi Mizuno

Abstract A mass measurement system which uses a dynamic vibration absorber as measuring device is developed. It can measure mass even under weightless conditions like in space stations. In this system, an object to be measured is fixed to a rotating table (rotor) at a distance from the rotational axis. Since it makes the rotor unbalanced, a centrifugal force causes the supporting structure to vibrate during rotation. A dynamic vibration absorber attached to the structure is tuned or controlled to cancel the excitation force. When the structure does not vibrate, the amplitude of motion of the auxiliary mass equals the ratio of the amount of unbalance to the auxiliary mass. Therefore, the mass of the object is determined from the motion of the auxiliary mass. According to the measurement principles, the vibration of the supporting structure must be eliminated. A servocompensator with the performance of automatic frequency tracking is applied to reduce the vibration. Experimental results demonstrate that mass can be measured accurately with the developed measurement system.


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