analogue methods of measuring pressure

Main Issues :

-Change in pressure -----> change in material (expanding/contracting, bending)

-Change in pressure -----> changes sealed gaseous liquid (aneroid device), liquid (alcohol, water, oil, mercury)

-Scale enlargement

Need to address:

Pressure Differential

Deflection

Air/Gas/Liquid expansion

Aneroid Barometer (Leibnitz 1844)

(means without water/liquid)

an=without

aer (air)

eidos (form)

-capsule device that moves with changes in pressure (an alloy of beryllium and copper)

-when the air has been partially removed from the box the surface depresses or expands with variation of air pressure on it.

-increase in atmospheric pressure increases air density

-expansion or contraction of the vacuum chamber is caused by change in air pressure

Article "Remote query pressure measurement using magnetoelastic sensors"

-inexpensive sensors

-no internal power supply

-remote query sensing of environmental parameters

Hanging Water Experiment

-the air around us is always pushing against something - it pushes in every direction

-the greater the air pressure pushing on the nylon/paper/silicon/vinyl is greater than the pressure of the weight of the water ie. air pressure.

http://www.elmhurst.edu/~chm/vchembook/180pressurefs.html

Denis Dingens article "Weatherinstruments" discusses the invention and development of different types of barometers and calibration of barometers for various sea levels.

http://www.barometers.com/images/meteo_english.pdf

feedback

Desk Crit:

-will need some sort of a transducer - a device that converts one type of energy to another. (Types of transducers - sensor, actuator, or a combination. A sensor is used to detect a parameter in one form and report it in another form of energy - usually an electrical and/digital signal). For example a pressure sensor might detect pressure (a mechanical form of energy) and convert it to electricity for display at a remote gauge. An actuator accepts energy and produces movement (action). The energy supplied to an actuator might be electrical or mechanical (pneumatic, hydraulic, etc.). An electric motor and a loudspeaker are both transducers, converting electrical energy into motion for different purposes. (source: wikipedia.com)

-sound is determined by pressure - fluctuations in pressure - make the sound audible

-building pressure (actuator) changes with heat/temperature/wind

-play with pressure and respond to it

-the issue is how to amplify and record the changes in pressure

-try to detect and make device to detect that

-pressure picks up movement - the ether - picks up displacements at all levels

-web cam - reverse lens - microscope - microelectronics - hack web cams - can't actually see but pays respect to

-if scale of pressure changes actual scale of actuator changes

-find ways of making things lightweight and small with large, delicate, sensitive spans

-make a material so responsive - with a large surface area - allow for deflection - something like balloons, inflatables? using helium, as pressure changes - is responsive ad how can make this work

-issue of calibration!!!!!! (will need to research this)

-exploring materiality what can do - materials sensitive to pressure

-issue of scale

-pressure - liquid/gaseous - changes

Searches: (MIT Press, Leonardo)

Soundstorm-email the artists

Department of Meteorology - to ask about measuring barometric pressure

Milieu- notion of milieu

Latour/Simondon

-how we negotiate a milieu determine where boundaries are

-interesting ways of looking at the world

ether - air/oxygen/locus of spirits - fluxes -moisture/pressure /energy/19th century biilluminescence

- how the world was described

Bruno Latour

"We have never been modern"

"Leviathan and the Air-pump" - Thomas Hobbes and Robert Boyle

-air-pump and proving the vacuum

-withnessing

-actor-network theory - parliment of things - the apparatus will determine what the experiment will be.

Georges Canguilhem

The Knowledge of Life in "The Living and it's Milieu"

-no distinction between fluid/gas/milieu/ether started to describe patterns in the world.

-perturbations - displaced not coming in or out

Will need to look at devices of amplifying and magnifying

**sensitivity

Look at barometers of the 18th Century - how was pressure monitored before it was digital?

-material amplification change ie. temperature in thermostat, use old devices to search for clues to measuring pressure

-find sensibility that can work with and that will determine what can work with

-barometric pressure -thin pipets - measuring change in length

those working with pressure

"In interactive art, mapping problem becomes increasingly complex, seeing that the public is invited to become an equal partner in the construction of meaning. This role is far more than merely fulfilling a role as an interpreter of (artistically) implied meaning.

"...'create an autonomous virtual social agent that is able to communicate...' such agents should be able to deal with capabilities of both synthesis and analysis. In order to do so, it is necessary to have a mapping strategy that is deduced from objective measurements, ideally cross-referenced with an analysis of subjective experience. This mapping strategy should also have a more universal nature than a mapping available to the public based solely on the artist's decisions. "

Interactivity and biometrics - "The choice for using a heart rate sensor is very much related to the belief that change in heart rate is an involuntary corporeal function, and thus it should behave on a more subliminal level than responses induced by cognition."

from "Coming from the heart: heart rate synchronization through sound" at http://biblio.ugent.be/input/download?func=downloadFile&fileOId=926016

Installation artists that use pulse pressure

Pulse Room

Soundstorm Installation

pressure sensors

Looking at converting a digital barometer to analogue in some manner. Need to develop a simple digital/analogue device, a device in registering something. Could be sound, inaudible at such a slow rate of change but compressed in time to make something more present.

A pressure sensor to act like a breathing mechanism, like lungs breathing as pressure changes, a heart beat is pressure changing. Flexing a material - becomes a system in and of itself. The approach of an observer changes the absolute pressure of the space, therefore no longer just being the observer but becoming part of of the environment.

Kinds of pressure: absolute

differential -moving from a high pressure to a low pressure can carry a force that can be converted to an electrical current - energy

gauge

(switch)

vacuum

Miniature Pressure Transducer

-designed to minimize sensor size while maintaining usable bandwidth.

-a foil strain gauge is coupled to a flat support plate, which is then mounted to the edges of a dome-like cover. When pressure is applied to the MPT, the support plate deforms, elongating the strain gauge.

-may need to connect to a Wheatstone bridge circuit to maximize the output of the sensor. This is the most commonly employed sensing technology for general purpose pressure measurement. Generally, these technologies are suited to measure absolute, gauge, vacuum, and differential pressures.

Altitude Sensing

-uses the relationship between changes in pressure relative to the altitude. Barometric pressure sensors can have an altitude resolution of less than 1 meter.

Strain Gauge Sensor

- simple accurate way to measure even sight deformation of a solid surface or object.

-Classified by material - usually a bended wire, metal foil, as a semiconductor

physical size

resistance

gauge factor - defined as the ration of the fractal change in resistance over the fractional change in length along the gauge axis

Force Sensitive Resistor (FSR)

-forcing sensing resistor has a variable resistance as a function of applied pressure therefore making it more of a pressure sensor.

Piezoelectricity - piezoelectric effect

-many materials exhibit piezoelectricity - biological tissues, ie. tendons, intestine, silk, bone, and wood

sensorwiki.org - exploration of various sensors

Barometric Pressure Power

Deriving Power from Atmospheric Pressure Differences over Geographically-Spaced Sites

Barometric Pressure Power

"A company called Cold Energy, claim they can tap into the energy consistently present in atmospheric pressure differences over long distances or elevation differences. The pressure differences creates a great deal of wind energy that can theoretically be challenged through a pipe to produce electrical energy, as air naturally rushes to the lower pressure end of the pipe. We witness this effect occurring every time a low pressure weather system passes over our area and wind rushes into the low pressure system, creating the wind that is a typical component of a storm. This is a novel, yet unproven, approach to tapping into a clean renewable energy source with tremendous energy potential.

"Anyone who has seen a weather report has seen maps with high pressure systems on one part of the map; and low pressure systems on another part of the map. Between these pressure systems, there are isobars - those wavy white lines that lie across the space between these pressure zones, indicating equal amounts of pressure, which create a pressure gradient (hill) that allows wind to flow naturally from high pressure to low pressure."

-The proposal is to run a pipe between the high to low pressure areas, you could tap into a tremendous amount of energy as the air rushes from the high pressure area to the low pressure area, and spin electric generating turbine from the flow of air between the two locations.

http://peswiki.com/index.php/Directory:Barometric_Pressure_Power

phenomenon of pressure

Pressure

[noun]

1 continuous physical force exerted on or against an object by something in contact with it; the force per unit area exerted by a fluid against a surface with which it is in contact

2 the use of persuasion or intimidation to make someone do something; the influence or effect of someone or something; a sense of stressful urgency caused by having too many demands on one's time or resources

[verb]

-attempt to persuade or coerce (someone) into doing something

Pressure (the symbol: P) is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.

Pressure is a scalar quantity. It is transmitted to solid boundaries or across arbitrary sections of fluid normal to these boundaries or sections at every point.

The standard atmosphere (atm) is an established constant. It is approximately equal to typical air pressure at earth mean sea level and is defined as follows:

standard atmosphere = 101325 Pa = 101.325 kPa

atmospheric pressure

ambient pressure

altitude sensing

surface pressure

dynamic pressure

internal pressure

pressure differential

dispersed pressure

concentrated pressure

directed pressure

negative pressure

vapor pressure

-pressure in relation to temperature changes, humidity, drafts, vibration, sound pressure are several potential explorations.

-wind speed and direction will also fluctuate the barometer

-air conditioning may create a pressure differential between the inside and outside of the room.

-use of a hygrometer to measure air humidity or the water vapor in the air.

the quasi-object

"Being or relating, that is the whole question."

"the quasi-object is not an object, but it is one nevertheless, since it is not a subject, since it is in the world; it is also a quasi-subject, since it marks or designates a subject who, without it, would not be a subject.

"the thread in his hands is our simple relation."

"This quasi-object, when being passed, makes the collective, if it stops, it makes the individual...The moving furet weaves the "we," the collective; if it stops, it marks the "I."

"Over there, on the ground, it is nothing; it is stupid; it has no meaning, no function, and no value. Ball isn't played alone."

"The ball is the subject of circulation; the players are only the stations and relays. The ball can be transformed into the witness of relays."

"The ball shuttles back and forth like the furet, weaving the collective, virtually putting to death each individual."

"This quasi-object that is a marker of the subject is an astonishing constructer of intersubjectivity...The "we" is made by the bursts and occultations of the "I." The "we" is made by passing the "I." And by substitution and vicariance of the "I."

"Words, bread, and wine are between us, beings or relations. We appear to exchange them between us though we are connected at the same table or with the same language."

"A symbol, but especially a symbol of the other. The symbolic is there; it is divided and is not divided. It is also a quasi-object. The quasi-object itself is a subject. The subject can be a quasi-object."

"Reciprocally: without referent, we are only blind men. We live only by relations."

studio 10/11

observer: pertubation device

the project brief:

"anything said is said by an observer. In his discourse the observer speaks to another observer, who could be himself: whatever applies to the one applies to the other as well. The observer is a human being, that is, a living system, and whatever applies to the living system applies to him." -Maturana and Varela

"...the building envelope inhabits a boundary condition that is often ambiguous... the complex layering of building materials that compose the interface of the surface address and modulates their own specific micro environmental conditions. These environmental (technical) elements have their own variable scale that are both molecular (capillary action) as well as human.

"As a dynamic system, the building envelop mitigates a variety of environmental and energetic systems. These systems may include, temperature differentials, light and solar energy, wind pressure, humidity and water infiltration and even the sonic conditions between these environments. Each of these conditions has the potential to develop into interplay between a sensing condition (both electronically and passively) as well as an opportunity for actuation. ... These conditions of environmental interplay are also polyscalar and polytemporal. ... The opportunity to develop and interactive script based on a temporal complexity resides in the relationship that is immediately available within a typical environmental interplay of a building membrane.

1. the device must sense immaterial phenomenon. In this sense, anything that is exposed to, surrounds or effects the environment of a building. This would include: sound, vibration, pressure, hydrology, humidity, light, heat, electromagnetic energy, radio waves etc. Any immaterial phenomenon that is affected or modulated by a building condition.

2. the device must translate this immaterial condition into a sensible analogue. ie. a phenomenological condition that reveals to the senses and makes apparent this immaterial condition. Hence in its action and monitoring of something that is invisible, it must make it tangible. Tangible to the point where its behaviors, its sensibilities can be tracked through time and space.

In interactive systems, we refer to this as mapping; where phenomenon that are unperceivable can be transformed into the perceivable by the calibration and the manipulation of the phenomenon; some strategies include, material translation, scaling (both in time and space) and even amplification.

"Our problem is the living organization and therefore our interest will not be in properties of components, but in the process and relations between processes realized through components." - Maturana and Varela