This document discusses different types of thermometers and how they work. It describes liquid thermometers like mercury and alcohol thermometers which use the property of thermal expansion. Gas thermometers measure the pressure of a confined gas. Resistance thermometers use platinum coils and its changing resistance. Thermoelectric thermometers utilize the Seebeck effect to convert temperature differences into electrical signals. Thermocouples and thermopiles are discussed as types of thermoelectric thermometers.
A thermocouple is a temperature-measuring device consisting of two dissimilar conductors that contact each other at one or more spots. It produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit.
1. THERMOCOUPLE
∙ Principle of Operation
∙ Materials Used
∙ Advantages
∙ Applications
∙ Comparison with RTD
∙ Limitations
By
AnandBongir
GirjashankarMishra
2. A thermocouple is a junction between two different metals that produces a voltage related to a temperature difference.
3. Principle of Operation
Thermocouples are based on the principle that two wires made of dissimilar materials connected at either end will generate a potential between the two ends that is a function of the materials and temperature difference between the two ends (also called the Seebeck Effect).
4. Seebeck Effect
5.
6. Materials Used
Type K:
Chromel – Alumel
• Range: −200 °C to +1350 °C
• Sensi: 41 µV/°C
Type J:
Iron – Constantan
• −40 to +750 °C
• 55 µV/°C
Type E:
Chromel – Constantan
• 401 to 900° C
• 68 µV/°C
Type N:
Nicrosil – Nisil
• >1200 °C
• 39 µV/°C
7. Advantages
It is rugged in construction
Covers a wide temperature range
Using extension leads and compensating cables, long transmission distances for temperature measurement possible. This is most suitable for temperature measurement of industrial furnaces
Comparatively cheaper in cost
Calibration can be easily checked
Offers good reproducibility
High speed of response
Satisfactory measurement accuracy
8. Limitations
For accurate temperature measurements, cold junction compensation is necessary
The emf induced versus temperature characteristics is somewhat nonlinear
Stray voltage pickup is possible
In many applications, amplification of signal is required
9. Applications
Type B, S, R and K thermocouples are used extensively in the steel and iron industries to monitor temperatures and chemistry throughout the steel making process.
Gas-fed heating appliances such as ovens & water heaters.
In the testing of prototype electrical and mechanical apparatus
A thermocouple is a temperature-measuring device consisting of two dissimilar conductors that contact each other at one or more spots. It produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit.
1. THERMOCOUPLE
∙ Principle of Operation
∙ Materials Used
∙ Advantages
∙ Applications
∙ Comparison with RTD
∙ Limitations
By
AnandBongir
GirjashankarMishra
2. A thermocouple is a junction between two different metals that produces a voltage related to a temperature difference.
3. Principle of Operation
Thermocouples are based on the principle that two wires made of dissimilar materials connected at either end will generate a potential between the two ends that is a function of the materials and temperature difference between the two ends (also called the Seebeck Effect).
4. Seebeck Effect
5.
6. Materials Used
Type K:
Chromel – Alumel
• Range: −200 °C to +1350 °C
• Sensi: 41 µV/°C
Type J:
Iron – Constantan
• −40 to +750 °C
• 55 µV/°C
Type E:
Chromel – Constantan
• 401 to 900° C
• 68 µV/°C
Type N:
Nicrosil – Nisil
• >1200 °C
• 39 µV/°C
7. Advantages
It is rugged in construction
Covers a wide temperature range
Using extension leads and compensating cables, long transmission distances for temperature measurement possible. This is most suitable for temperature measurement of industrial furnaces
Comparatively cheaper in cost
Calibration can be easily checked
Offers good reproducibility
High speed of response
Satisfactory measurement accuracy
8. Limitations
For accurate temperature measurements, cold junction compensation is necessary
The emf induced versus temperature characteristics is somewhat nonlinear
Stray voltage pickup is possible
In many applications, amplification of signal is required
9. Applications
Type B, S, R and K thermocouples are used extensively in the steel and iron industries to monitor temperatures and chemistry throughout the steel making process.
Gas-fed heating appliances such as ovens & water heaters.
In the testing of prototype electrical and mechanical apparatus
This Presentation Will Help You To Discover Knowledge About Basic Principles Of Thermocouples. this Presentation Also give You Governing Effect Knowledge & Working Principles Of Thermocouples. In Details You Will Get History and Definitions Of Thermocouples. This Presentation Has Best Diagrams also So that You Can Get Knowledge Easily. At The End You Will See Applications Of Thermocouples In Day to Day Life.
The thermocouple is a device which converts thermal energy to electrical energy. It is particularly used as a thermosensor. It has wider applications in instrumentation and measurements.
This PPT gathered many relevant topics relating to thermocouple like its working, principle, laws and different types.
Thank you!
An RTD (Resistance Temperature Detector) is a sensor whose resistance changes as its temperature changes. The resistance increases as the temperature of the sensor increases. The resistance vs temperature relationship is well known and is repeatable over time. An RTD is a passive device. It does not produce an output on its own. External electronic devices are used to measure the resistance of the sensor by passing a small electrical current through the sensor to generate a voltage. Typically 1 mA or less measuring current, 5 mA maximum without the risk of self-heating.
RTDs are built to several standardized curves and tolerances.
The most common standardized curve is the ‘DIN’ curve. The curve describes the resistance vs temperature characteristics of a Platinum, 100 ohm sensor, the standardized tolerances, and the measurable temperature range.
The DIN standard specifies a base resistance of 100 ohms at 0°C, and a temperature coefficient of .00385 Ohm/Ohm/°C. The nominal output of a DIN RTD sensor is shown below:
There are three standard tolerance classes for DIN RTDs. These tolerances are defined as follows:
DIN Class A: ±(0.15 + .002 |T|°C)
DIN Class B: ±(0.3 + .005 |T|°C)
DIN Class C: ±(1.2 + .005 |T|°C)
This Presentation can be used by the Students of Engineering who Deals with the Subject INDUSTRIAL INSTRUMENTATION and use it for Refrence (Anyways you Guys will Copy Paste or Download it) ;)
This Presentation Will Help You To Discover Knowledge About Basic Principles Of Thermocouples. this Presentation Also give You Governing Effect Knowledge & Working Principles Of Thermocouples. In Details You Will Get History and Definitions Of Thermocouples. This Presentation Has Best Diagrams also So that You Can Get Knowledge Easily. At The End You Will See Applications Of Thermocouples In Day to Day Life.
The thermocouple is a device which converts thermal energy to electrical energy. It is particularly used as a thermosensor. It has wider applications in instrumentation and measurements.
This PPT gathered many relevant topics relating to thermocouple like its working, principle, laws and different types.
Thank you!
An RTD (Resistance Temperature Detector) is a sensor whose resistance changes as its temperature changes. The resistance increases as the temperature of the sensor increases. The resistance vs temperature relationship is well known and is repeatable over time. An RTD is a passive device. It does not produce an output on its own. External electronic devices are used to measure the resistance of the sensor by passing a small electrical current through the sensor to generate a voltage. Typically 1 mA or less measuring current, 5 mA maximum without the risk of self-heating.
RTDs are built to several standardized curves and tolerances.
The most common standardized curve is the ‘DIN’ curve. The curve describes the resistance vs temperature characteristics of a Platinum, 100 ohm sensor, the standardized tolerances, and the measurable temperature range.
The DIN standard specifies a base resistance of 100 ohms at 0°C, and a temperature coefficient of .00385 Ohm/Ohm/°C. The nominal output of a DIN RTD sensor is shown below:
There are three standard tolerance classes for DIN RTDs. These tolerances are defined as follows:
DIN Class A: ±(0.15 + .002 |T|°C)
DIN Class B: ±(0.3 + .005 |T|°C)
DIN Class C: ±(1.2 + .005 |T|°C)
This Presentation can be used by the Students of Engineering who Deals with the Subject INDUSTRIAL INSTRUMENTATION and use it for Refrence (Anyways you Guys will Copy Paste or Download it) ;)
Gives a brief introduction about temperature measurement and its unit. it also enumerates the different techniques employed in temperature measurement.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
3. What is Temperature?
A measure of the average kinetic energy of the particles in
a sample of matter, expressed in terms of units or degrees
designated on a standard scale.
4. What is mean by thermometers
It is a device to define and measure the temp. of a
system . When thermometer is in thermal equilibrium
with the system
5. How a Thermometer Works ?
We need :
1- Physical property that changes uniformly with change in
temperature .
2- Fixed points.
Freezing point , boiling point .
3- Temperature scale. (Celsius , Kelvin , Fahrenheit)
6. Basic physical ideas for making
thermometers
The variation in length of a solid;
The variation in volume of a fixed mass of gas at constant pressure;
The variation in pressure of a fixed mass of gas at constant volume;
The variation in resistance of a metal;
The variation in color of a very hot body;
The variation in electromotive force of a thermocouple.
7. C
Zeroth law of thermodynamics
A B
Two systems each in thermal equilibrium with a third system are
in thermal equilibrium with each other.
Two systems are in thermal equilibrium only if they have the
same temperature.
8. Scales of Temperature
Lower fixed point This is the temperature of pure melting ice, at a
pressure of a standard atmosphere.
Upper fixed point This is the temperature of dry steam from water
boiling at a pressure of one standard atmosphere.
Fundamental interval This is the distance between the fixed points.
It is divided into a number of equal divisions. Each division is one
degree.
9. Discus conditions governing the choice of properties and materials for temperature measurement
by a thermometer.
1. The substance must have a considerable variation over a small increase in temperature.
That means, it must be very sensitive to a small change of temperature.
2. The change in the property of the substance must occur rapidly.
3. The range of temperature over which the thermometer can be used should be as large as
possible.
4. The thermometric substance should have a small thermal capacity. This means that it must
readily acquire the temperature of its surrounding.
5. The time taken to acquire this temperature should be small. This will minimize time lag when
it is used and when variation of temperature should follow.
10. The systems of temperature scales are:
(i) The Celsius scales whose ice point is 0 C and the steam point is
at 100 C. Each part represents 1 C.
(ii) The Fahrenheit scale whose ice point is 32F while the steam
point if 212 F. The fundamental interval is 180 divisions.
(iii) The absolute scale of temperature, the thermodynamics scale.
This will be discussed later.
Scales of Temperature
11. Where x is physical properties (length , volume ,
resistance , electromotive force .
Scales of Temperature
13. Scales of Temperature
Example 1.1 In an unmarked mercury thermometer the length lo was
4 cm, and l100 24cm. What are the temperatures when lT is (a) 16 cm, (b)
28 cm and (c) 2 cm?
16. The relationships of the four
temperature scales
oRoFoCK
672o212o100o373Steam point
180 oR180 Fo100 Co100 K
492o32o0o273Ice point
0o-460o
-273o0oAbsolute zero
17. Fill in the blanks
ice
steam 100
273 32
212
-40
= (5/9)[TF-32] = (5/9) (-72) = - 40T TC F
o
5
9
32( )
233
22. Constant Volume Gas Thermometer
A constant-volume gas
thermometer measures the
pressure of the gas contained in the
flask immersed in the bath. The
volume of gas in the flask is kept
constant by raising or lowering
reservoir B to keep the mercury
level in column A constant.
23. Bimetallic Thermometers
The principle behind a bimetallic strip
thermometer relies on the fact that
different metals expand at different
rates as they warm up. By bonding
two different metals together, you can
make a simple electric controller that
can withstand fairly high
temperatures. This sort of controller is
often found in ovens.
25. Platinum Resistance Thermometer
it is far more accurate
it has a very large range;
it can be read at a distance if
it has long leads.
Thermometer
leads
Compansating
leads
Platinum coil
Mica strip
26. Disadvantages of platinum thermometer
its chief disadvantage is the long time needed for it to assume the
temperature of its surroundings and the time required for making
an observation so that it cannot follow rapidly changing
temperatures.
28. Seebeck effect
Seebeck effect simply states that if two dissimilar metals, such as copper and iron are joined
to make a complete circuit, then on heating one end of the junctions, a current flows round
the circuit
Thermo-electric Thermometer
29. The presence of the galvanometer is to detect and measure the magnitude of
the current that flows in the circuit.
This type of arrangement is called a thermo-couple.
The emf established round the circuits depends on the nature of the metals
used to form the couple and also on the temperature difference between the
hot and cold junctions.
Thermo-electric Thermometer
30. Thermo-electric Thermometer
It has a low thermal capacity and can be used to :
measure fluctuating temperatures;
It has a very large range, from -200C to 1500 oC depending
upon the metals used for the thermocouple;
It can measure the temperature at a point.
32. Thermopile
A thermopile is an electronic device
that converts thermal
energy into electrical energy. It is
composed of several thermocouples
connected usually in series or, less
commonly, in parallel.
33. Questions
State the five conditions necessary for the choice of properties and the
substance used for temperature measurement.
Mention four types of thermometers and their appropriate thermometric
properties used for their construction.
A body has temperature of about 1200 C. Which thermometer would you use
and why?