Say the word and you'll be free.
Say the word and be like me.

("The Word," by the Beatles, 1965)

PTOA Segment #94:  Where Do We Go From Here? (#3): 

The following terminology that was introduced in PTOA Segment #94 described some of the technologies that would be featured in the upcoming PTOA Temperature Detection and Measurement Focus Study Area:

• Bi-metallic strips
• Bourdon tubes
• RTDs (Resistance-Temperature Detectors)
• Thermistors
• Thermocouples

 

 

PTOA Segment #95: Temperature Measurement Must-Knows (Part 1)

Chemical Property/Properties (of Stuff/Matter/Mass): Characteristics of Stuff/Matter/Mass which determine the tendency of how the Stuff/Matter/Mass in question will interact with other Stuff/Matter/Mass and ultimately end up creating a completely different type of Stuff/Matter/Mass.

Examples of chemical properties are:

• Flammability (tendency to combust if oxygen is present)
• Oxidation/Corrosion Tendency
• pH (relative acidity or alkalinity).

Chemical Properties typically require a lab analysis to quantify.

The PTOA Temperature Detection and Measurement Focus Study was not concerned with the chemical properties of Stuff/Matter/Mass; the concept was introduced to delineate it from important physical properties that are used to detect and measure temperature.

Chemical properties will be featured in future PTOA Segments that focus on the chemical reactions that take place in reactors.

 

Electrical Conductivity (of Stuff/Matter/Mass): A physical property that sounds to the ear like it should be classified as a chemical property and which ... like most chemical properties ... would need to be quantified by a laboratory because it is not possible to just look at a sample of Stuff/Matter/Mass to determine its electrical conductivity.

The relevant feature about electrical conductivity is that its inverse is electrical resistivity, a physical property that makes it possible for RTDs and thermistors to function.

 

Physical Property/Properties (of Stuff/Matter/Mass): All the properties that describe what Stuff/Matter/Mass looks like to the naked eye, for example:

• Color
• What physical state the Stuff/Matter/Mass is in (gas, liquid, solid)
• How fast the Stuff/Matter/Mass will pour when in the liquid state.
• How easy the solid state of the Stuff/Matter/Mass would bend into a different shape without breaking.

Some physical properties would require a lab test to quantify accurately, for example:

• Boiling Point, Melting Point, Freezing Point.
• Electrical Conductivity and its inverse, Electrical Resistivity.
• Density, or how much Stuff/Matter/Mass will fit into a container of known volume.

 

 

PTOA Segment #96:  Temperature Measurement Must-Knows (Part 2)

Absolute Temperature Scales: Temperature scales that are not based on the freezing and boiling point of water but rather extend the low temperature scale to the theoretical point where no molecular agitation occurs (and therefore no heat can be transferred ... because heat is the outcome of agitated molecules bumping into each other).

 

Kelvin Scale (°K): The Absolute Temperature Scale that can be easily correlated to the Centigrade/Celsius temperature scale by adding 273.15 to any temperature measured in °C:

°K = °C + 273.15

 

Linear thermal expansion/contraction of materials: The length-wise increase/decrease in materials ... but especially metals ... when heat transfer increases/decreases into/out of the material of interest.

 

Rankin Scale (°R):The Absolute Temperature Scale that can be easily correlated to the Fahrenheit temperature scale by adding 459.67 to any temperature measured in °F:

°R = °F + 459.67

 

Table of Linear Expansion Coefficients: A table that lists many types of materials and their comparative coefficients of linear thermal expansion.

As long as the coefficient units are the same, the relative amount of linear expansion between two materials can be determined by dividing the coefficient for one material by another.

 

 

PTOA Segment #97: Stringing the Pearls of Temperature Wisdom

No additional process industry jargon was introduced in PTOA Segment #97.

 

 

 

PTOA Segment #98: I Used to be Half Empty ... Now I am Half Full!

Bourdon Tube: A fluid-filled tube that is fixed at one end; thus ... when the fluid inside expands or contracts with a change in pressure (C-shaped) or temperature (helical shaped) ... the resulting deflection of the tube can be linked to a pointer and dial face which generates a process variable reading that human beings can understand.

A device that converts molecular movement (caused by thermal excitation) into mechanical movement.

A type of transducer because transducers convert one type of energy into another and Bourdon Tubes convert molecular movement (caused by thermal excitation) into mechanical movement.

 

Bulb: The reservoir of a liquid-in-glass thermometer that contains the working liquid that is going to expand when heated and contract when cooled.

 

Capillary Tube: The glass stem of a liquid-in-glass thermometer which is attached to the bulb and into which the heated working liquid expands when heat is transferred into it and contracts when heat is transferred out of it ... which both change the height of the column of working fluid.

 

Bulb-Capillary System: The industrial-strength counterpart to the liquid-in-glass thermometer.

A fluid-filled device that can detect and ... with the addition of a helical Bourdon Tube, pointer, and dial ...  measure temperature based upon the thermal expansion and contraction of a working fluid.

The working fluid is not restricted to being a liquid; the working fluid might be a volatile liquid moving between the gas and liquid phases.

 

Liquid-in-Glass Thermometer: The common household temperature detection and measuring device we human beings call "a thermometer" ... even though all of the temperature detecting and measuring devices featured in the PTOA Temperature Detection and Measurement Focus Study are thermometers.

A temperature detecting/measuring device that has a working liquid ... typically mercury .. enclosed within a bulb and capillary.

A temperature detecting/measuring device that works because the amount that the working liquid will expand or contract upon being heated or cooled is predictable.

 

Working Liquid: The liquid enclosed in a liquid-in-glass thermometer that expands when heat is transferred into it and contracts when heat is transferred out of it. The working liquid in common household liquid-in-glass thermometers is mercury.

 

©2016 PTOA Segment 0133
PTOA Process Industry Jargon Recap 4-1

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