Amperometric Sensor
Electrochemical gas sensors operate by reacting with the analyte and
producing an electrical signal. Most electrochemical gas sensors are
amperometric sensors, generating a current that is linearly proportional
to the gas concentration. The principle behind amperometric sensors is
the measurement of the current-potential relationship in an
electrochemical cell where equilibrium is not established. The current
is quantitatively related to the rate of the electrolytic process at the
sensing electrode (also known as working electrode) whose potential
commonly is kept constant using another electrode (the so-called
reference electrode).
Working Principle
A MEMBRAPOR electrochemical gas sensor works as follows: Target gas
molecules that come in contact with the sensor first pass an
anti-condensation membrane which serves also as a protection against
dust. Then the gas molecules diffuse through a capillary, potentially
through a subsequent filter, and then through a hydrophobic membrane to
reach the surface structure of the sensing electrode. There the
molecules are immediately oxidized or reduced on active catalytic sites,
consequently producing or consuming electrons, and thus generating an
electric current.
It is important to note that with this approach the amount of gas
molecules entering the sensor is limited by the diffusion through the
capillaries. By optimizing the pathway, in accordance with the desired
measurement range, an adequate electrical signal is obtained.
The design of the sensing electrode is crucial in order to both achieve a
high reactivity towards the target gas and to inhibit undesired
responses to interfering gases. It involves a system of three phases:
solid, liquid and gaseous, and all are involved in the chemical
recognition of the analyte gas. MEMBRAPOR is passionately dedicated to
tailor this system and obtain high-performance gas sensors.
The electrochemical cell is completed by the so-called counter electrode
which balances the reaction at the sensing electrode. The ionic current
between the counter and sensing electrode is transported by the
electrolyte inside the sensor body, whereas the current path is provided
through wires terminated with pin connectors.
Commonly, a third electrode is included in an electrochemical sensor
(3-electrode sensor). The so-called reference electrode serves to
maintain the potential of the sensing electrode at a fixed value. For
this purpose and generally for the operation of an electrochemical
sensor a potentiostatic circuit is needed.
Sensor Signal
The output signal of a MEMBRAPOR gas sensor corresponds to the
concentration of a gas rather than to its partial pressure. Hence, it is
possible to use a MEMBRAPOR sensor at different altitudes or even
underground, independent at which atmospheric pressure the device was
calibrated.
A deeper and scientific explanation of the sensor output and the pressure dependence can be found in the document MEM4.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
2016年3月2日星期三
Absorption biased single beam NDIR gas sensor
An Absorption Biased (AB) methodology for NDIR gas sensors is used with a
single infrared source and a detector to detect a single gas of
interest by using a motion device to change the path length between that
of the signal and reference channels.
As in the case of the AB designed NDIR gas sensor, the ratio of the output of the Signal channel, measured during location arrangement X, over that of the Reference channel, measured during location arrangement Y, will be used to process the gas measurement.
Multiple gases of interest can be detected by using one detector to detect multiple gases and/or by locating a second detector to detect multiple gases more distant from the source than the first detector, thereby creating longer path lengths for the second detector.
BACKGROUND OF THE INVENTION
All molecules vibrate and rotate at characteristic frequencies in the electromagnetic spectrum. These vibration/rotational frequencies cause asymmetric molecules such as CO2 and H2O, but not symmetric molecules like N2 or O2, to absorb light at very specific wavelengths, particularly in the infrared. The NDIR gas measurement technique targets these characteristic absorption bands of asymmetric molecules of gases in the infrared for their detection. The term “non-dispersive” which actually implies “non-spatially-dispersive” as used herein refers to the apparatus used, typically a narrow-band infrared transmission filter instead of a spatially-dispersive element such as a prism or diffraction grating, for isolating for the purpose of measurement the radiation in a particular wavelength band that coincides with a strong absorption band of a gas to be measured.
The NDIR technique has long been considered as one of the best methods for gas measurement. In addition to being highly specific, NDIR gas sensors are also very sensitive, relatively stable and easy to operate and maintain. In contrast to NDIR gas sensors, the majority of other types of gas sensors today are in principle interactive. Interactive gas sensors are less reliable, short-lived and generally non-specific, and in some cases can be poisoned or saturated into a nonfunctional or irrecoverable state.
Despite the fact that interactive gas sensors are mostly unreliable and that the NDIR gas measurement technique is one of the best there is, NDIR gas sensors still have not enjoyed widespread high volume usage to date. The main reasons for this can generally be attributed to their high unit production cost, relatively large size and output drifts over time.
Just about all gas sensors ever designed and manufactured to date, irrespective of what technology is being employed, invariably have significant output drifts over time. While NDIR gas sensors can be recalibrated as part of a periodic maintenance program or service, the cost of such recalibration has prevented NDIR gas sensors from being widely adopted for many applications.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
As in the case of the AB designed NDIR gas sensor, the ratio of the output of the Signal channel, measured during location arrangement X, over that of the Reference channel, measured during location arrangement Y, will be used to process the gas measurement.
Multiple gases of interest can be detected by using one detector to detect multiple gases and/or by locating a second detector to detect multiple gases more distant from the source than the first detector, thereby creating longer path lengths for the second detector.
BACKGROUND OF THE INVENTION
All molecules vibrate and rotate at characteristic frequencies in the electromagnetic spectrum. These vibration/rotational frequencies cause asymmetric molecules such as CO2 and H2O, but not symmetric molecules like N2 or O2, to absorb light at very specific wavelengths, particularly in the infrared. The NDIR gas measurement technique targets these characteristic absorption bands of asymmetric molecules of gases in the infrared for their detection. The term “non-dispersive” which actually implies “non-spatially-dispersive” as used herein refers to the apparatus used, typically a narrow-band infrared transmission filter instead of a spatially-dispersive element such as a prism or diffraction grating, for isolating for the purpose of measurement the radiation in a particular wavelength band that coincides with a strong absorption band of a gas to be measured.
The NDIR technique has long been considered as one of the best methods for gas measurement. In addition to being highly specific, NDIR gas sensors are also very sensitive, relatively stable and easy to operate and maintain. In contrast to NDIR gas sensors, the majority of other types of gas sensors today are in principle interactive. Interactive gas sensors are less reliable, short-lived and generally non-specific, and in some cases can be poisoned or saturated into a nonfunctional or irrecoverable state.
Despite the fact that interactive gas sensors are mostly unreliable and that the NDIR gas measurement technique is one of the best there is, NDIR gas sensors still have not enjoyed widespread high volume usage to date. The main reasons for this can generally be attributed to their high unit production cost, relatively large size and output drifts over time.
Just about all gas sensors ever designed and manufactured to date, irrespective of what technology is being employed, invariably have significant output drifts over time. While NDIR gas sensors can be recalibrated as part of a periodic maintenance program or service, the cost of such recalibration has prevented NDIR gas sensors from being widely adopted for many applications.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
Receptor Function and Response of Semiconductor Gas Sensor
Theoretical approaches to receptor function and response of semiconductor gas sensor are described, following the illustrations of
some relevant key issues such as tunneling transport. Depletion in small
semiconductor crystals is characterized by the occurrence of new type
depletion (volume depletion) after conventional one (regional
depletion), and inclusion of both types makes it possible to formulate
the receptor function and response to oxygen (air base), oxidizing gas
(nitrogen dioxide), and reducing gas (hydrogen). The equations derived
theoretically using physical parameters of the semiconductor side and
chemical parameters of the gases side appear to reproduce satisfactorily
the sensing behavior to the aforementioned gases as well as the
influence of changes in physical parameters such as grain size and donor
density. Extension to the semiconductor crystals dispersed with surface
electron-traps shows that the traps act as a sensitizer to promote
sensor response.
1. Introduction
A semiconductor gas sensor (called device hereafter) possesses an electrical resistance made with a porous assembly of tiny crystals of an n-type metal oxide semiconductor, typically SnO2, In2O3, or WO3. The crystals are often loaded with a small amount of foreign substance (noble metals or their oxides) called a sensitizer. When operated at adequate temperature in air, the resistor changes its resistance sharply on contact with a small concentration of reducing gas or oxidizing gas, enabling us to know the concentration from the resistance change. For its inauguration with a report by Seiyama et al. and a patent by Taguchi, this group of sensors has been subjected to a tremendous amount of R&D efforts world wide aiming at improvements of sensing performances and extensions to new applications. Thanks to these researches, the group not only has grown to provide important tools to detect and/or control gases in places in modern society but also has pioneered to founding a new technology field where the devices are called chemical sensors. Speaking more exactly, semiconductor gas sensors have been classified into two subtypes, that is, surface-sensitive type operating at temperatures below 500∘C and bulk-sensitive one operating at high temperature (typically at 800∘C) . This article is concerned with those of the former type only.
Apart from such remarkable achievements in practical applications, basic understandings of this group of sensors have hardly been satisfactory, despite tremendous efforts of so many researchers as summarized in reviews [5–8]. This is partly because there are many complex factors which affect sensing properties. Not only the selection of a proper oxide semiconductor is important but also the methods and conditions for fabricating sensor devices exert profound influences on gas sensing properties through changes in donor density, crystallite size, contacting geometry between crystals, packing density (or porosity), packing thickness, and so on. In addition, the sensing properties are often modified largely with loading with foreign substances such as sensitizers. Understandings of these phenomena indeed have required interdisciplinary knowledge among semiconductor physics, surface chemistry, solid-state chemistry, and so on. In order to facilitate the understandings, we have proposed to assume that the sensing properties are determined by three main factors, that is, receptor function, transducer function, and utility factor, as schematically shown in Figure 1. The first factor is concerned with how each constituent crystal responds to the surrounding atmosphere containing oxygen and target gases (intraparticle issue).
It is unanimous that oxygen is adsorbed on the crystals as negatively charged species, accompanied by the formation of a depletion layer inside the crystals. The target gases disturb the equilibrium through being adsorbed competitively or reacting with the adsorbed oxygen. The foreign substances like sensitizers dispersed on the crystals are assumed to affect these processes anyhow. The second factor is concerned with how the response of each particle is transformed into that of the whole device, and apparently this is related with the mechanism of electron transport between adjacent crystals (inter-particle issue). For a long time a double Schottky barrier model [9], which assumes migration transport of electrons over the barrier as shown, has been advocated for this process without critical check. The third one is concerned with the attenuation of the response due to the effect of diffusion and reaction of reactive target gases through the pores of the assembly of crystals (assembly issue) . The above scheme has explained rather well qualitative nature of semiconductor gas sensors in several respects. However, it has failed to give quantitative understandings and, most importantly, to give new insights leading to innovations of this group of sensors. There should have been some serious defaults included in the scheme, particularly regarding the receptor and transducer functions.
Figure 1: Three factors determining the response of semiconductor gas sensors.
Fortunately, we encountered an interesting finding several years ago that thin film devices fabricated from hydrothermally prepared colloidal suspensions of SnO2 by a spin-coating technique showed temperature—almost independent resistances in air in the temperature range 150–400∘C, as shown in Figure 2. Such thermal behavior of resistances is hardly consistent with the double Schottky barrier model mentioned above. Instead, tunneling transport of electrons across the contacts (or gaps) between adjacent crystals is strongly suggested. In addition, this transport mechanism has made much easier the theoretical modeling of receptor and transducer functions recently carried out [14–16], because the constituent crystals can now be treated independently from each other. As revealed during this process, depletion in small crystals easily goes beyond conventional one (regional depletion) to enter new type one (volume depletion). Obviously, it is a lack of such information that has delayed fundamental understandings of this group of sensors, for most of their valuable gas sensing properties show up in the stage of volume depletion or nearby.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
1. Introduction
A semiconductor gas sensor (called device hereafter) possesses an electrical resistance made with a porous assembly of tiny crystals of an n-type metal oxide semiconductor, typically SnO2, In2O3, or WO3. The crystals are often loaded with a small amount of foreign substance (noble metals or their oxides) called a sensitizer. When operated at adequate temperature in air, the resistor changes its resistance sharply on contact with a small concentration of reducing gas or oxidizing gas, enabling us to know the concentration from the resistance change. For its inauguration with a report by Seiyama et al. and a patent by Taguchi, this group of sensors has been subjected to a tremendous amount of R&D efforts world wide aiming at improvements of sensing performances and extensions to new applications. Thanks to these researches, the group not only has grown to provide important tools to detect and/or control gases in places in modern society but also has pioneered to founding a new technology field where the devices are called chemical sensors. Speaking more exactly, semiconductor gas sensors have been classified into two subtypes, that is, surface-sensitive type operating at temperatures below 500∘C and bulk-sensitive one operating at high temperature (typically at 800∘C) . This article is concerned with those of the former type only.
Apart from such remarkable achievements in practical applications, basic understandings of this group of sensors have hardly been satisfactory, despite tremendous efforts of so many researchers as summarized in reviews [5–8]. This is partly because there are many complex factors which affect sensing properties. Not only the selection of a proper oxide semiconductor is important but also the methods and conditions for fabricating sensor devices exert profound influences on gas sensing properties through changes in donor density, crystallite size, contacting geometry between crystals, packing density (or porosity), packing thickness, and so on. In addition, the sensing properties are often modified largely with loading with foreign substances such as sensitizers. Understandings of these phenomena indeed have required interdisciplinary knowledge among semiconductor physics, surface chemistry, solid-state chemistry, and so on. In order to facilitate the understandings, we have proposed to assume that the sensing properties are determined by three main factors, that is, receptor function, transducer function, and utility factor, as schematically shown in Figure 1. The first factor is concerned with how each constituent crystal responds to the surrounding atmosphere containing oxygen and target gases (intraparticle issue).
It is unanimous that oxygen is adsorbed on the crystals as negatively charged species, accompanied by the formation of a depletion layer inside the crystals. The target gases disturb the equilibrium through being adsorbed competitively or reacting with the adsorbed oxygen. The foreign substances like sensitizers dispersed on the crystals are assumed to affect these processes anyhow. The second factor is concerned with how the response of each particle is transformed into that of the whole device, and apparently this is related with the mechanism of electron transport between adjacent crystals (inter-particle issue). For a long time a double Schottky barrier model [9], which assumes migration transport of electrons over the barrier as shown, has been advocated for this process without critical check. The third one is concerned with the attenuation of the response due to the effect of diffusion and reaction of reactive target gases through the pores of the assembly of crystals (assembly issue) . The above scheme has explained rather well qualitative nature of semiconductor gas sensors in several respects. However, it has failed to give quantitative understandings and, most importantly, to give new insights leading to innovations of this group of sensors. There should have been some serious defaults included in the scheme, particularly regarding the receptor and transducer functions.
Figure 1: Three factors determining the response of semiconductor gas sensors.
Fortunately, we encountered an interesting finding several years ago that thin film devices fabricated from hydrothermally prepared colloidal suspensions of SnO2 by a spin-coating technique showed temperature—almost independent resistances in air in the temperature range 150–400∘C, as shown in Figure 2. Such thermal behavior of resistances is hardly consistent with the double Schottky barrier model mentioned above. Instead, tunneling transport of electrons across the contacts (or gaps) between adjacent crystals is strongly suggested. In addition, this transport mechanism has made much easier the theoretical modeling of receptor and transducer functions recently carried out [14–16], because the constituent crystals can now be treated independently from each other. As revealed during this process, depletion in small crystals easily goes beyond conventional one (regional depletion) to enter new type one (volume depletion). Obviously, it is a lack of such information that has delayed fundamental understandings of this group of sensors, for most of their valuable gas sensing properties show up in the stage of volume depletion or nearby.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
2016年3月1日星期二
List of temperature sensors
Mechanical temperature sensors
Thermometer
Therm
Electrical temperature sensors
Thermistor- Thermistors are thermally sensitive resistors whose prime function is to exhibit a large, predictable and precise change in electrical resistance when subjected to a corresponding change in body temperature. Negative Temperature Coefficient (NTC) thermistors exhibit a decrease in electrical resistance when subjected to an increase in body temperature and Positive Temperature Coefficient (PTC) thermistors exhibit an increase in electrical resistance when subjected to an increase in body temperature.
Thermocouple
Resistance thermometer
Silicon bandgap temperature sensor
Integrated circuit sensors
Manufacturers
Analog Devices
Microchip
Texas Instruments
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
The umbrella that KNOWS when it's going to rain: 'Oombrella' uses humidity sensors to warn you
If you've ever been caught in a rain shower without your umbrella, or
left it on a bench or bus, this high-tech version may be for you.
Not only is the 'Oombrella' brightly coloured so you won't miss it, it will send you a reminder if you unwittingly leave it behind or if it's about to rain.
What's more, the world's first 'smart and connected' umbrella can predict the weather for the next half hour, using its humidity sensors as well as data from a social media community.
The umbrella sends the user updates on weather, as well as reminders if they have left the brolly behind. The 'Oombrella' will also share data with people already using the weather app Wezzoo in order to gather and share information on local weather with its users
The colourful brolly connects with a social weather service and shares weather information collected from the service to let users know when it's going to start raining.
The reflective multi-coloured Oombrella uses built-in sensors to record light, humidity, and temperature.
All of this information is collated and analysed before being sent to the owner's smartphone, providing instant local weather updates.
This transforms its customers into into 'mobile weather stations', the company said, which can predict rain half an hour before it hits.
The reflective multi-coloured Oombrella uses technology to record light, humidity, and temperature, before it is collated, analysed and broadcast back to smartphones, providing almost instant local weather updates
The reflective multi-coloured Oombrella transforms its users into into mobile weather stations, which can predict rain half an hour before it hits
The umbrella will also send alerts if it realises its owner has accidentally left it at home or in a restaurant for example, using a built-in GPS tracker.
Oombrellas are not for sale yet but they will be available on Kickstarter this March and in shops and online in Autumn.
'The retail price is €79 (£62.09/$86) and early bird price is €59 (£46.36/$64.20) on Kickstarter', a company spokesman told MailOnline.
The product will ship globally, he added.
And while the current design is bulky to carry around, a smaller version is in development.
The designers, French-based company Wezzoo, call the umbrella 'smart' because it collects weather-related data on the go and 'connected' because it sends hyperlocal weather data and receives real time severe weather alerts.
The Oombrella will send alerts to your mobile phone if it realises you accidentally leave it at home or in a restaurant, using its GPS tracker
Oombrellas are not for sale yet but they will be available on Kickstarter this winter. The weather app Wezzoo is already used in 189 countries and in five different languages. Oombrella users will connect and share their weather data with the Wezzoo community
The Oombrella will also share data with people already using their weather app Wezzoo - to gather and share information on local weather.
Wezzoo is a social and real-time weather service that lets users share their local weather and look at the weather elsewhere.
Users can share their location and photographs of the weather to keep each other up to date.
The app additionally adds data coming from mobile sensors including temperature, humidity, pressure and light.
It is available on both iOS and Android and is already used worldwide in 189 countries and in 5 languages.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
Not only is the 'Oombrella' brightly coloured so you won't miss it, it will send you a reminder if you unwittingly leave it behind or if it's about to rain.
What's more, the world's first 'smart and connected' umbrella can predict the weather for the next half hour, using its humidity sensors as well as data from a social media community.
The umbrella sends the user updates on weather, as well as reminders if they have left the brolly behind. The 'Oombrella' will also share data with people already using the weather app Wezzoo in order to gather and share information on local weather with its users
The colourful brolly connects with a social weather service and shares weather information collected from the service to let users know when it's going to start raining.
The reflective multi-coloured Oombrella uses built-in sensors to record light, humidity, and temperature.
All of this information is collated and analysed before being sent to the owner's smartphone, providing instant local weather updates.
This transforms its customers into into 'mobile weather stations', the company said, which can predict rain half an hour before it hits.
The reflective multi-coloured Oombrella uses technology to record light, humidity, and temperature, before it is collated, analysed and broadcast back to smartphones, providing almost instant local weather updates
The reflective multi-coloured Oombrella transforms its users into into mobile weather stations, which can predict rain half an hour before it hits
The umbrella will also send alerts if it realises its owner has accidentally left it at home or in a restaurant for example, using a built-in GPS tracker.
Oombrellas are not for sale yet but they will be available on Kickstarter this March and in shops and online in Autumn.
'The retail price is €79 (£62.09/$86) and early bird price is €59 (£46.36/$64.20) on Kickstarter', a company spokesman told MailOnline.
The product will ship globally, he added.
And while the current design is bulky to carry around, a smaller version is in development.
The designers, French-based company Wezzoo, call the umbrella 'smart' because it collects weather-related data on the go and 'connected' because it sends hyperlocal weather data and receives real time severe weather alerts.
The Oombrella will send alerts to your mobile phone if it realises you accidentally leave it at home or in a restaurant, using its GPS tracker
Oombrellas are not for sale yet but they will be available on Kickstarter this winter. The weather app Wezzoo is already used in 189 countries and in five different languages. Oombrella users will connect and share their weather data with the Wezzoo community
The Oombrella will also share data with people already using their weather app Wezzoo - to gather and share information on local weather.
Wezzoo is a social and real-time weather service that lets users share their local weather and look at the weather elsewhere.
Users can share their location and photographs of the weather to keep each other up to date.
The app additionally adds data coming from mobile sensors including temperature, humidity, pressure and light.
It is available on both iOS and Android and is already used worldwide in 189 countries and in 5 languages.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
Breath alcohol test | Industry sourcing
A breath alcohol test determines how much alcohol is in your blood by
measuring the amount of alcohol in the air you breathe out (exhale).
How the Test is Performed
There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual.
One common manual tester requires you to blow up a balloon in one continuous breath until it is full, then release the air into a glass tube. The tube is filled with bands of yellow crystals. The bands in the tube change colors (from yellow to green), depending on the alcohol content. Carefully read the instructions before using the test to make sure you get an accurate result.
If an electronic alcohol meter is used, follow the instructions that come with the meter.
How to Prepare for the Test
Wait 15 minutes after drinking an alcoholic beverage and 1 minute after smoking before starting the test.
How the Test Will Feel
There is no discomfort.
Why the Test is Performed
When you drink alcohol, the amount of alcohol in your blood goes up. This is called your blood-alcohol level.
When the amount of alcohol in the blood reaches 0.02 to 0.03%, you may feel a relaxing "high."
When that percentage reaches 0.05 to 0.10%, you have:
• Reduced muscular coordination
• A longer reaction time
• Impaired judgment
Driving and operating machinery under the influence of alcohol is dangerous. A person with an alcohol level of 0.08% and above is considered legally intoxicated (drunk) in most states. (Some states have lower levels than others.)
The alcohol content of exhaled air accurately reflects the alcohol content of the blood.
Normal Results
Normal is when the blood alcohol levels are not elevated.
What Abnormal Results Mean
When 1 band is green, it means that the blood-alcohol level is 0.05% or lower. 2 green bands mean levels of 0.05% to 0.10%. 3 green bands indicate levels between 0.10% and 0.15%.
Risks
There are no risks.
Considerations
The test does not take into account the driving abilities of the test subject. Driving abilities vary among people with the same blood-alcohol levels. Some people with blood-alcohol levels below 0.05% may not be able to safely drive. For occasional drinkers, judgment problems occur at blood-alcohol levels of just 0.02%.
The breath alcohol test helps you to know how much alcohol it takes to raise the blood-alcohol level to a dangerous level. Each person's response to alcohol varies. The test may help you make better decisions about driving after drinking.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
How the Test is Performed
There are various brands of breath alcohol tests. Each one uses a different method to test the level of alcohol in the breath. The machine may be electronic or manual.
One common manual tester requires you to blow up a balloon in one continuous breath until it is full, then release the air into a glass tube. The tube is filled with bands of yellow crystals. The bands in the tube change colors (from yellow to green), depending on the alcohol content. Carefully read the instructions before using the test to make sure you get an accurate result.
If an electronic alcohol meter is used, follow the instructions that come with the meter.
How to Prepare for the Test
Wait 15 minutes after drinking an alcoholic beverage and 1 minute after smoking before starting the test.
How the Test Will Feel
There is no discomfort.
Why the Test is Performed
When you drink alcohol, the amount of alcohol in your blood goes up. This is called your blood-alcohol level.
When the amount of alcohol in the blood reaches 0.02 to 0.03%, you may feel a relaxing "high."
When that percentage reaches 0.05 to 0.10%, you have:
• Reduced muscular coordination
• A longer reaction time
• Impaired judgment
Driving and operating machinery under the influence of alcohol is dangerous. A person with an alcohol level of 0.08% and above is considered legally intoxicated (drunk) in most states. (Some states have lower levels than others.)
The alcohol content of exhaled air accurately reflects the alcohol content of the blood.
Normal Results
Normal is when the blood alcohol levels are not elevated.
What Abnormal Results Mean
When 1 band is green, it means that the blood-alcohol level is 0.05% or lower. 2 green bands mean levels of 0.05% to 0.10%. 3 green bands indicate levels between 0.10% and 0.15%.
Risks
There are no risks.
Considerations
The test does not take into account the driving abilities of the test subject. Driving abilities vary among people with the same blood-alcohol levels. Some people with blood-alcohol levels below 0.05% may not be able to safely drive. For occasional drinkers, judgment problems occur at blood-alcohol levels of just 0.02%.
The breath alcohol test helps you to know how much alcohol it takes to raise the blood-alcohol level to a dangerous level. Each person's response to alcohol varies. The test may help you make better decisions about driving after drinking.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
High accuracy air flow sensor for industrial applications
The EE75 air velocity transmitters (air flow sensors) are optimized for
high accuracy up to 40 m/s (8000 ft/min) over the temperature range
-40...120 °C (-40...248 °F).
ISweek - Industry sourcinghe robust sensing probe and enclosure allow for EE75 use in harsh industrial environment as well as in applications with pressure rating up to 10 bar (145 psi).
Beside measuring air velocity and temperature, EE75 calculates the volumetric flow rate in m³/h or ft³/min based on the cross section of the duct, with an appropriate factory correction. The EE75 can be used to measure the velocity of various non-flammable and non-corrosive gases.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
ISweek - Industry sourcinghe robust sensing probe and enclosure allow for EE75 use in harsh industrial environment as well as in applications with pressure rating up to 10 bar (145 psi).
Beside measuring air velocity and temperature, EE75 calculates the volumetric flow rate in m³/h or ft³/min based on the cross section of the duct, with an appropriate factory correction. The EE75 can be used to measure the velocity of various non-flammable and non-corrosive gases.
iSweek（http://www.isweek.com/）- Industry sourcing & Wholesale industrial products
订阅：
博文 (Atom)