temperature Flashcards
temperature definition
measure of the average translational kinetic energy associated with the microscopic movement of molecules
zeroth law of thermodynamics
if two objects are in thermal equilibrium with a third object then they are also in thermal equilibrium with each other
K = C _______
K = C +273.15
F = ___C _______
F = 1.8C +32
R = F _______
R = F +459.67
types of temperature measurement devices
thermometer
resistance temperature detector
thermistor
thermocouple
seebeck effect
if two dissimilar materials are joined together an emf will exist between the open end points, which is a function of the temperature at the junction
Peltier effect
heating due to current flow raises temp. in one junction and lowers temp. in the other
Thompson effect
flow of current and flow of heat in the conductor due to temp. gradient is proportional to (current)x(change in time)
four thermocouple laws
law of homogeneous material
law of intermediate materials
law of intermediate temperatures
law of additive voltages
law of homogeneous materials
a thermoelectric current cannot be sustained in a circuit of a single homogeneous material by the application of heat
law of intermediate materials
a third intermediate wire can be inserted in series with one of the wires without changing the voltage reading, provided that the two new junctions are at the same temp
law of intermediate temperatures
if a thermocouple circuit consisting of two materials A and B generates an emf E12 between junctions T1 & T2, and an emf E23 between junctions T2 & T3, then it will create an emf E13 = E12 + E23 between junctions T1 & T3
law of additive voltages
for a given set of thermocouples with materials AB, BC and AC, all measuring the same temp. difference T1-T2, the voltage measured by AC must equal the sum of the voltages measured by AB and BC
