Determination of ec ,temp , oil & greaseJenson Samraj
Here, my topic is based on the Determination of Oil and grease which is a rare topic and in it its all discussed in a very easiest concept so that all the users can improve their knowledge by this presentation.
Determination of ec ,temp , oil & greaseJenson Samraj
Here, my topic is based on the Determination of Oil and grease which is a rare topic and in it its all discussed in a very easiest concept so that all the users can improve their knowledge by this presentation.
A Comparison Study Between Two Hydrogen Sensorsijtsrd
In this research work, a comparison study has been carried out between Palladium Pd coated PMMA Poly Methyl Meth acryl ate optical sensor and Palladium thin films sensor that have been prepared on glass substrates. PMMA were sputter coated with Palladium using a sputter coating facility offered by the He riot Watt University, during sputter coating the target palladium is showered with argon gas such that atoms from the target are ejected by the ionized gas and then deposited on the PMMA substrate. Palladium thin films have been prepared on glass substrates by vaporization deposition technique with annealing temperature is around 600 C. Relative inertness of the sensors to relative humidity makes it specific to detect hydrogen at low concentration. Target environments for the proposed sensors are fuel cell cabinets, industrial process plants, submarines, nuclear fuel power generation and decommissioning plants. Results showed that optical characteristics of the prepared sensors are highly sensitive, but their properties considerably vary when the measurements conducted in vacuum or in air. In the two sensors the response-recovery time of Pd materials to hydrogen gas characterized to be extremely short. Dr. Albashir Zomrawi "A Comparison Study Between Two Hydrogen Sensors" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-6 , October 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18443.pdf
Presentation given by Luis Pereira (on behalf of Antonin Chapoy) from Heriot-Watt University on "Impacts of impurities on thermophysical properties and dehydration requirements of CO2-rich systems in CCS" in the Effects of Impurities Technical Session at the UKCCSRC Biannual Meeting - CCS in the Bigger Picture - held in Cambridge on 2-3 April 2014
Analytical Measurements: Troubleshooting, Maintenance and the FutureISA Boston Section
Focuses on measurement of pH, ORP (Redox), and Conductivity and aspects related to inline measurement of these critical analytical parameters. Discussion topics include scientific theory, measurement challenges, proper troubleshooting, installation, key applications, and the future of analytical measurements
pH Measurement Principles and Best Measurement Practices | WebinarXylem Inc.
The pH presentation begins with an introduction of how a pH electrode actually works.
After establishing these basics, we cover the different structures that make up an electrode, which will lead us into electrode selection.
Perhaps the most practical portion of this webinar is focused on calibration, measurement, maintenance, and storage tips. After selecting an electrode, these tips will ensure the data you collect is accurate… and repeatable.
IQ Academy Lunch & Learn Webinar | Cost Effective Water Quality Monitoring wi...IQ_UK
Lots of water quality monitoring is undertaken by the quarrying industry as part of demonstrating environmental permit compliance to the Regulator as well as day to day operational control. Cost is a very important driver in monitoring design and implementation but must not be at the expense of quality and effectiveness. This webinar will discuss how to maximise the effectiveness of water quality monitoring whilst also minimising cost.
Delivered by Dr Craig Speed, an Associate Director and Hydrochemist in Wardell Armstrong’s Water team. Craig has over 13 years of water consultancy experience and 4 years’ experience working for the Environment Agency. His expertise includes design, management and review of water quality monitoring (both groundwater and surface water), hydrochemical interpretation, providing lectures on water quality monitoring at Birmingham University, knowledge of UK water legislation (including environmental permits and abstraction licensing) and detailed knowledge of the Water Framework Directive (WFD) including WFD Compliance Assessments.
His recent project experience includes historic metal mine impact assessments, a quarry lake hydrochemistry project, a quarry conceptual model review, hydrogeology lead in major infrastructure projects, key expert in groundwater monitoring for a project in Turkey and conducting an investigation and adjudication following lime stabilisation impacts on water quality for an electrical infrastructure company.
A Comparison Study Between Two Hydrogen Sensorsijtsrd
In this research work, a comparison study has been carried out between Palladium Pd coated PMMA Poly Methyl Meth acryl ate optical sensor and Palladium thin films sensor that have been prepared on glass substrates. PMMA were sputter coated with Palladium using a sputter coating facility offered by the He riot Watt University, during sputter coating the target palladium is showered with argon gas such that atoms from the target are ejected by the ionized gas and then deposited on the PMMA substrate. Palladium thin films have been prepared on glass substrates by vaporization deposition technique with annealing temperature is around 600 C. Relative inertness of the sensors to relative humidity makes it specific to detect hydrogen at low concentration. Target environments for the proposed sensors are fuel cell cabinets, industrial process plants, submarines, nuclear fuel power generation and decommissioning plants. Results showed that optical characteristics of the prepared sensors are highly sensitive, but their properties considerably vary when the measurements conducted in vacuum or in air. In the two sensors the response-recovery time of Pd materials to hydrogen gas characterized to be extremely short. Dr. Albashir Zomrawi "A Comparison Study Between Two Hydrogen Sensors" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-2 | Issue-6 , October 2018, URL: http://www.ijtsrd.com/papers/ijtsrd18443.pdf
Presentation given by Luis Pereira (on behalf of Antonin Chapoy) from Heriot-Watt University on "Impacts of impurities on thermophysical properties and dehydration requirements of CO2-rich systems in CCS" in the Effects of Impurities Technical Session at the UKCCSRC Biannual Meeting - CCS in the Bigger Picture - held in Cambridge on 2-3 April 2014
Analytical Measurements: Troubleshooting, Maintenance and the FutureISA Boston Section
Focuses on measurement of pH, ORP (Redox), and Conductivity and aspects related to inline measurement of these critical analytical parameters. Discussion topics include scientific theory, measurement challenges, proper troubleshooting, installation, key applications, and the future of analytical measurements
pH Measurement Principles and Best Measurement Practices | WebinarXylem Inc.
The pH presentation begins with an introduction of how a pH electrode actually works.
After establishing these basics, we cover the different structures that make up an electrode, which will lead us into electrode selection.
Perhaps the most practical portion of this webinar is focused on calibration, measurement, maintenance, and storage tips. After selecting an electrode, these tips will ensure the data you collect is accurate… and repeatable.
IQ Academy Lunch & Learn Webinar | Cost Effective Water Quality Monitoring wi...IQ_UK
Lots of water quality monitoring is undertaken by the quarrying industry as part of demonstrating environmental permit compliance to the Regulator as well as day to day operational control. Cost is a very important driver in monitoring design and implementation but must not be at the expense of quality and effectiveness. This webinar will discuss how to maximise the effectiveness of water quality monitoring whilst also minimising cost.
Delivered by Dr Craig Speed, an Associate Director and Hydrochemist in Wardell Armstrong’s Water team. Craig has over 13 years of water consultancy experience and 4 years’ experience working for the Environment Agency. His expertise includes design, management and review of water quality monitoring (both groundwater and surface water), hydrochemical interpretation, providing lectures on water quality monitoring at Birmingham University, knowledge of UK water legislation (including environmental permits and abstraction licensing) and detailed knowledge of the Water Framework Directive (WFD) including WFD Compliance Assessments.
His recent project experience includes historic metal mine impact assessments, a quarry lake hydrochemistry project, a quarry conceptual model review, hydrogeology lead in major infrastructure projects, key expert in groundwater monitoring for a project in Turkey and conducting an investigation and adjudication following lime stabilisation impacts on water quality for an electrical infrastructure company.
An ideal I.S.E. consists of a thin membrane across which only the
intended ion can be transported.
The transport of ions from a high conc. to a low one through a selective binding with some sites within the membrane creates a
Blood gas analyser & blood gas analysis with clinical significanceerohini sane
A comprehensive presentation on Blood Gas Analyzer and Blood Gas Analysis for self- learning undergraduate medical ,dental, ,pharmacology and biotechnology students . Laboratory determination of blood gas analysis –Micro method & technical errors involved are described.
Blood sample collection for blood gas analysis is illustrated.
Principle & Important components of Blood gas Analyzer are presented in lucid language.
Polari graphic method for PO₂ Measurement using pO₂ electrode is explained. Integral parts of pO₂ electrode ie platinum electrode, silver /silver chloride reference electrode & their working (reaction at electrode) is presented here.
Design of pCO2, & pH electrodes along with their working principles are elucidated for perusal of technologist.
Typical reference ranges in blood gas analysis are mentioned and are useful to classify acid base imbalance. Nomogram of acid base disorder is illustrated for clinical applications.
Laboratory determination of blood gas analysis along with its standardization is presented step wise. The Henderson’s Hassel Balch equation pursuing interrelation of TCO₂, Bicarbonate, Carbonic acid, PCO ₂, & p H is presented for manual calculation of certain parameters.
Google images are used for impact of subject on self-learners.
Gas chromatography- “It is a process of separating component(s) from the given crude drug by using a gaseous mobile phase.”
Principle- The principle of separation in GC is “partition.”
The mixture of components to be separated is converted to vapor and mixed with the gaseous mobile phase.
The component which is more soluble in the stationary phase travels slower and eluted later.
The component which is less soluble in the stationary phase travels faster and eluted out first.
No two components have the same partition coefficient conditions.
So the components are separated according to their partition coefficient.
The partition coefficient is “the ratio of solubility of a substance distributed between two immiscible liquids at a constant temperature.’
It involves a sample being vaporized and injected onto the head of the chromatographic column.
The sample is transported through the column by the flow of inert, gaseous mobile phase.
The column itself contains a liquid stationary phase which is adsorbed onto the surface of an inert solid.
Two major types:
1. gas-solid chromatography: Here, the mobile phase is a gas while the stationary phase is a solid.
Used for separation of low molecular gases,
e.g., air components, H2S, CS2, CO2, rare gases, CO, and oxides of nitrogen.
2.Gas-liquid chromatography: The mobile phase is a gas while the stationary phase is a liquid retained on the surface as an inert solid by adsorption or chemical bonding.
Advantages-
Both qualitative and quantitative analyses are possible.
The instrument is simple, time of analysis is short.
High sensitivity.
The method is applicable to about 60% of organic compounds.
Very small sample sizes can be used.
Analysis can be highly accurate and precise.
Applications-
Quality control and analysis of drug products like antibiotics (penicillin), antivirals (amantadine), general anesthetics (chloroform, ether), sedatives/hypnotics (barbiturates), etc.
Assay of drugs – purity of a compound can be determined for drugs like :
Atropine sulfate
Clove oil
Stearic acid
In determining the levels of metabolites in body fluids like plasma, serum, urine, etc
Estimation of spoilage components, such as histamine and carbonyls, that cause rancidity.
Proposal written by a team of chemical engineers at UC Berkeley in order to suggest alternative solutions for effectively irrigating and restoring the Dow Wetlands site in Antioch, CA.
A new technique to measure oxygen reduction kinetics underneath coatings using hydrogen permeation from the back side. Huge step towards characterising buried interface reactivity.
Polarographic technique is applied for the qualitative or quantitative analysis of electroreducible or oxidisable elements or groups.
It is an electromechanical technique of analyzing solutions that measures the current flowing between two electrodes in the solution as well as the gradually increasing applied voltage to determine respectively the concentration of a solute and its nature.
The principle in polarography is that a gradually increasing negative potential (voltage) is applied between a polarisable and non-polarisable electrode and the corresponding current is recorded.
Polarisable electrode: Dropping Mercury electrode
Non-polarisable electrode: Saturated Calomel electrode
From the current-voltage curve (Sigmoid shape), qualitative and quantitative analysis can be performed. This technique is called as polarography, the instrument used is called as polarograph and the current-voltage curve recorded is called as polarogram
Voltage drop calculator for street lights. Works with Excel 365. Get file by downloading presentation.
Open object presentation. Click 'Enable Content'. Right click over object for "Package Shell Object"->"Activate Content"->Press "OPEN" button to see VDROP folder. Open folder for the files.
This is provided "AS IS" with no warranty or guarantees or liability.It is accurate, but make sure to check with your standards to be sure.
Wiring a pH and Conductivity Probe to a Zeno3200TAMUK
Short guide explaining how wire a pH and conductivity sensor to a Zeno 3200 data logger. The models mentioned may not be manufactured anymore at this time.
A user guide for setting up a stock Zeno 3200 data logger to work with wind speed, wind direction, and input voltages from an air monitor. Includes how to log in to Zeno 3200 with Hyperterminal and building the serial cable.
This model is probably not made anymore. This user guide explained how to assemble some hardware and use the software to set up an SDI water depth sensor.
Draft of a lab manual. Talks about the use of tape, using a balance, DI water, care of pH probes, pictures and descriptions of equipment. Still working on it.
A short slide presentation showing how to calibrate a Dasibi 1008 series ozone monitor and some numbers to look for to determine whether it is a leak or valve issue.
A short document describing how to set up a datalogger, ozone generator, and ozone monitor to expose rats to ozone. I had help set this up some time ago for a pharmacy research project. It is not necessarily the only way or best way since there many other similar items available, but it did work.
Instructions for Submissions thorugh G- Classroom.pptxJheel Barad
This presentation provides a briefing on how to upload submissions and documents in Google Classroom. It was prepared as part of an orientation for new Sainik School in-service teacher trainees. As a training officer, my goal is to ensure that you are comfortable and proficient with this essential tool for managing assignments and fostering student engagement.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The Art Pastor's Guide to Sabbath | Steve ThomasonSteve Thomason
What is the purpose of the Sabbath Law in the Torah. It is interesting to compare how the context of the law shifts from Exodus to Deuteronomy. Who gets to rest, and why?
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
The Indian economy is classified into different sectors to simplify the analysis and understanding of economic activities. For Class 10, it's essential to grasp the sectors of the Indian economy, understand their characteristics, and recognize their importance. This guide will provide detailed notes on the Sectors of the Indian Economy Class 10, using specific long-tail keywords to enhance comprehension.
For more information, visit-www.vavaclasses.com
Unit 8 - Information and Communication Technology (Paper I).pdfThiyagu K
This slides describes the basic concepts of ICT, basics of Email, Emerging Technology and Digital Initiatives in Education. This presentations aligns with the UGC Paper I syllabus.
Welcome to TechSoup New Member Orientation and Q&A (May 2024).pdfTechSoup
In this webinar you will learn how your organization can access TechSoup's wide variety of product discount and donation programs. From hardware to software, we'll give you a tour of the tools available to help your nonprofit with productivity, collaboration, financial management, donor tracking, security, and more.
Ethnobotany and Ethnopharmacology:
Ethnobotany in herbal drug evaluation,
Impact of Ethnobotany in traditional medicine,
New development in herbals,
Bio-prospecting tools for drug discovery,
Role of Ethnopharmacology in drug evaluation,
Reverse Pharmacology.
1. 9/17/2013
1
• pH
• Conductivity
• Temperature
• Dissolved oxygen
Each of these is described by standard method
published by the EPA or ASTM
http://www.standardmethods.org/
National Environmental Methods Index
https://www.nemi.gov/
Standard Operating Procedures: Continuous Water
Quality Monitoring Network (TCEQ)
http://www.tceq.texas.gov/waterquality/monitoring/cwqm_sops.html
Aquatic Sensor Workgroup
http://www.watersensors.org/
Surface Water Quality Monitoring
http://www.tceq.texas.gov/waterquality/monitoring/index.html
2. 9/17/2013
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• ORP – oxidation/reduction potential
• Turbidity – cloudiness or haziness. Measured with a nephelometer.
• Nitrate (NO3-)
• Ammonium (NH4+) / ammonia (NH3-)
• Chloride (Cl-)
• Rhodamine – for monitoring dyes
• Chlorophyll
• Reference: http://www.ysi.com/parameters.php
A measurement of the average kinetic energy of particles
in a substance.
Thermistor – a semiconductor material that has a change in
resistance in proportion to the change in temperature
Calibration standards are based on a constant room temperature
of 25ºC (77ºF)
3. 9/17/2013
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• In chemistry, a measurement of the acidity or alkalinity of a solution
which is determined by the number of H+ or OH- ions in solution.
• First introduced by a Danish chemist in 1909 and revised to the modern
version in 1924.
• Origins of ‘pH’: The subscript ‘h’ referenced in first papers. Could have
been ‘power’ or ‘power of hydrogen’ (from German or French).
• Based on a logarithmic scale (10x) and is from the range of 0 to 14 where 7
is defined as neutral
• Streams, creeks, rivers, lakes, groundwater
• Affected by: bedrock and soil composition, organic growth in the water,
dumping of chemicals, acid rain, drainage waste (from mine tailings for
example)
• References: http://www.all-about-ph.com/ ,
http://en.wikipedia.org/wiki/PH
Always remember:
● Logarithmic
● 10x for pH
4. 9/17/2013
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The pH probe is made up of a few essential parts.
The glass bulb, KCL referencegel, Silver Chloride coated wire,
and the reference junction.
The glass bulb is filled with a stable pH solution, usually pH 7,
that experiences constant binding of Hydrogen ions.
The outside of the bulb is exposed to the water, where the
Hydrogen ions vary.
The difference in Hydrogen ions creates a potential that is read
versus the stable potential of the referenceelectrode.
This signal is sent via the Silver Chloride coated wire to the
instrument, where it is measured as a voltage and then
converted to pH units.
References: http://www.all-about-ph.com/ph-electrode.html
http://www.ysi.com/media/support/YSI-Making-Good-pH-Measurements-web.pdf
Based on the Nernst Equation which is
Mathematical description of an ideal pH electrode
Behavior. Introduced by the German chemist
Hermann Nernst in 1889.
For a (3) point calibration, buffers 4, 7, 10 used.
One can do a 1, 2, or 3 point calibration.
The figure to right shows the effecton the electrode
signal at various temperatures. The isothermal point
of a pH electrode is defined as the intersection
point of different temperature lines, see the figure.
The isopotential point, or the zero point, is then
point where electrode output is 0.0 mV.
For an ideal pH electrode, this would represent an
isothermal intersectionat the zero point
(0 mV at pH 7) for different temperatures.
5. 9/17/2013
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Do’s:
• Be sure you always store your pH probe in a moist environment, at the least, to prevent it
from drying out.
• Water-saturated air is the minimum you would need to store your probe in a short-term
situation. Short-term is three weeks or less.
• The best way to store your probe when not in use is submerged in pH 4 buffer or pH storage
solution. This is also recommended for long-term storage, which is longer than three weeks.
• Do develop a routine maintenance program that includes reconditioning the pH probe prior
to the field season.
• Do maintain good calibration records to track your probes performance.
Don’ts:
• Never store pH Probe submerged in DI water. It will dilute the internal electrolyte and
shorten the probe’s life.
• Never allow your probe to sit in dry air for extended periods of time. If the probe has been
improperly stored or allowed to dry out, it is very likely the probe will need to be replaced.
• Be sure to prevent probes from being subjected to below freezing temperatures or exposed to
excessive heat.
• When cleaning, avoid using a brush or any other material that could scratch the surface of the
glass bulb. Scratches will affect your probe’s stability.
Reference: http://www.ysi.com/media/support/YSI-Making-Good-pH-Measurements-web.pdf
Conductivity is a measure of the ability of water to pass an electrical current.
Conductivity in water is affected by the presence of inorganic dissolved solids
such as chloride, nitrate, sulfate, and phosphate anions (ions that carry a
negative charge) or sodium, magnesium, calcium, iron, and aluminum cations
(ions that carry a positive charge).
Organic compounds like oil, phenol, alcohol, and sugar do not conduct electrical current very well
and therefore have a low conductivity when in water.
Conductivity is also affected by temperature: the warmer the water, the higher the conductivity.
For this reason, conductivity is reported as conductivity at 25 degrees Celsius (25 C).
● Units: milli-Siemens/cm, micro-Siemens/cm
Reference: http://water.epa.gov/type/rsl/monitoring/vms59.cfm
6. 9/17/2013
6
Fig 2: Most conductivity meters have a
two-electrode cell (see illustration)
available in either dip or flow-through
styles. The electrode surface is usually
platinum, titanium, gold-plated nickel, or
graphite.
● Fig 1: The basic unit of conductance is the
siemen (S), formerly called the mho. Since
cell geometry affects conductivity values,
standardized measurements are
expressed in specific conductivity units
(S/cm) to compensate for variations in
electrode dimensions. Specific
conductivity (C) is simply the product of
measured conductivity (G) and the
electrode cell constant (L/A), where L is
the length of the column of liquid between
the electrodes and A is the area of the
electrodes (see illustration). C = G x (L/A)
Reference: http://www.coleparmer.com/TechLibraryArticle/78
Varies slightly from manufacturer, but typically a (1) point
calibration. TCEQ uses 1413 uS.
The procedure is to rinse the probe in DI water, and shake
and wipe excess water. Place the probe into the calibration
solution and make sure to dunk the entire probe into the
solution.
Once the reading is settled, set the calibration point
(depends upon meter).
Conductivity solution maybe a potassium chloride,
sodium chloride, or TDS 442 (mix of mixture of sodium
sulfate (40%), sodium bicarbonate (40%) and sodium
chloride (20%). The 442 mixture is designed to mimic the
ions often present in natural fresh water systems.
7. 9/17/2013
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Each is a measure of salts dissolved in sample.
● Conductivity – how well the water conducts
electrical current which is proportional to the
dissolved ions in a sample
● Salinity - is a special measure of dissolved solids
based upon concentration of ocean salts. Technically,
the measurement of salinity requires comparing a
sample's TDS (Total Dissolved Solids), conductivity,
or other physio-chemical property with that of a
standard sea water.
● Salinity is the usual measure of salts in sea water
and in brackish water derived from mixing of fresh
and sea water.
8. 9/17/2013
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The amount of oxygen (O2) dissolved in water.
Also referred to sometimes as oxygen saturation.
Cold water can hold higher levels than warm water.
Correction factors for solubility and salinity
Typical units: millilitres O2 per liter (ml/L), millimoles O2 per liter (mmol/L),
milligrams O2 per liter (mg/L) and moles O2 per cubic meter (mol/m3),
'percent saturation‘
Percent saturation - the amount of oxygen in a liter of water relative to the total
amount of oxygen that the water can hold at that temperature
Dissolved Oxygen Values above 100% (Read)
http://www.ysi.com/media/pdfs/T602-Environmental-Dissolved-Oxygen-Values-Above-100-
percent-Air-Saturation.pdf
Reference: http://water.epa.gov/type/rsl/monitoring/vms52.cfm
Note: mg/L is ppm
9. 9/17/2013
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The electrochemical method of measuring DO requires a cathode,
anode, electrolyte solution and a gas permeable membrane.
The material of the membrane is specially selected to permit
oxygen to pass through. Oxygen is consumed by the cathode which
will create a partial pressure across the membrane. Oxygen will
then diffuses into the electrolyte solution.
Thus, a DO meter actually measures the pressure of oxygen in water.
It can be used to measure DO in any medium.
Polarographicor Clark Cell Method
Dr. Clark first discovered the cell to measure oxygen in 1956. This is basically an
amperometric (polarographic) cell that is polarized around 800 mV. This cell, named after
Dr. Clark, is built around the popular Ag/AgCl half-cell and a noble metal such as gold,
platinum or palladium. Reduction of oxygen is achieved between 400 to 1200 mV, hence a
need for a voltage of around 800 mV. This is provided externally by a battery source.
Galvanic Method using to dissimilar metals and an electrolyte, so it requires no warm up
time or external voltage source
Reference: http://www.eutechinst.com/techtips/tech-tips15.htm
10. 9/17/2013
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Lifetime and intensity optical measurement methods detect dissolved oxygen
based on the well documented principle that dissolved oxygen quenches
both the lifetime and intensity of the luminescence associated with carefully chosen
chemical dyes. When there is no oxygen present, the lifetime and
intensity of the signal are at their maximum. As oxygen is introduced
to the sensing element, both the lifetime and intensity of the luminescence
become shorter. Therefore, the lifetime and intensity of the luminescence
are inversely proportional to the amount of oxygen present. The relationship
between the oxygen pressure outside the sensor and the lifetime or intensity
of the luminescence in the dye layer of the sensing element can be generally
quantified by the Stern-Volmer equation (Io/I = 1 + kqt0 * O2). However, the Stern-
Volmer equation implies an inversely linear relationship which is not strictly
true especially at higher oxygen concentrations; therefore, YSI employs the
use of a 3rd order polynomial to correct for this non-linearity and to obtain
the desired range of dissolved oxygen readings.
Reference: The Dissolved Oxygen Handbook
According to YSI, the sensors should
be calibrated in the following order:
Specific Conductance,
pH mid-range (7.0),
pH low (4.0) or high range (10),
Dissolved Oxygen
http://www.tceq.texas.gov/assets/public/compliance/monops/water/wqm/forms/YSI_CaLo
gbook.pdf
11. 9/17/2013
11
• pH
• Conductivity/TDS
• DO
• Temperature
Compare with values at FM 70 and past values.
http://www.tceq.texas.gov/waterquality/tmdl/nav/32-petronila/32-petronila-
tds
“Petronila Creek, Segment 2204, is a 44-mile freshwater stream spanning
Kleberg and Nueces counties. Located southwest of Corpus Christi,
PetronilaCreek is part of the Baffin Bay watershed.
In 2000, water quality testing found elevated levels of chloride, sulfate, and
TDS in the creek. High concentrations of these salts are indicators of general
water quality that are not tied to a specific use, but may affect several uses.
“
Water temperature and conductivity collected in real time at the creek:
http://www.tceq.state.tx.us/cgi-
bin/compliance/monops/water_site_photo.pl?cams=731