Tempco TEC-9300, Instruction Manual

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Current proportioning:
A 4–20 milliamp (typical) current output
which provides a current proportional to the amount of control
required.
Current transformer:
A transformer, intended for measuring purposes,
designed to generate a current at its secondary winding which is proportion-
al to the current at the primary winding.
Cycle time:
The time, usually expressed in seconds, for a controller to
complete one on/off cycle.
Data logging:
Recording a process variable over an extended period of
time.
DC:
Direct Current; An electric current flowing in one direction and con-
stant in value.
Dead band:
1. For chart recorders: the minimum change of input signal
required to cause a deflection in the pen position. 2. For temperature con-
trollers: the temperature band where heat is turned off upon rising tem-
perature and turned on upon falling temperature expressed in degrees.
The area where no heating (or cooling) takes place.
Default parameters:
The parameters, or programmed instructions,
permanently stored in microprocessor software to provide a data base.
Derivative:
(see Rate)
Deviation:
The difference between the value of the controlled variable
and the value at which it is being controlled.
Deviation alarm:
An offset value that follows the set point. If the set
point is 350°F and the deviation alarm value is +20°F, the alarm value
would be 350°F plus 20°F (or 370°F), See Process alarm.
Dielectric strength:
An amount of voltage that an insulating material
can withstand before an electrical breakdown occurs.
Differential:
In an on/off control, the temperature difference, expressed
in degrees, between where the control switches off and the control
switches on.
Differential control:
A controller can control one process in relation to
the difference of a second process.
DIN:
Deutsche Industrial Norms. A German agency that sets engineering
and dimensional standards that now has worldwide recognition.
Drift:
A change in a value over a long period due to changes in factors
such as ambient temperature, time, or line voltage.
Droop:
In time proportioning controls, the difference in temperature
between the set point and where the system temperature stabilizes.
Corrected by automatic or manual reset.
Dual output:
The primary output will regulate the process temperature.
A secondary output will be utilized for process cooling or as an alarm.
Duty cycle:
Percentage of “load ON time” relative to total cycle time.
Efficiency:
The amount of useful output versus energy input.
Electrical interference:
Electrical noise induced upon the signal
wires that obscures the wanted information signal.
Electromagnetic Compatibility (EMC):
A system that meets three
requirements: 1. it does not cause interference with other systems, 2. it is
not susceptible to emissions from other systems and 3. it does not cause
interference with itself.
Electromagnetic Interference (EMI):
An electrical and magnetic
noise which can be generated when switching inductive devices, light-
ning, radio wave radiation, electrostatic discharge, etc.
emf:
Electromotive force. A rise in (electrical) potential energy. The
principal unit is the volt.
Emissivity:
The ratio of energy emitted by an object to the energy emit-
ted by a blackbody at the same temperature. The emissivity of an object
depends upon its material and surface texture; a polished metal surface
can have an emissivity around 0.2, and a piece of wood can have an
emissivity around 0.95.
Endothermic:
Absorbs heat. A process is said to be endothermic when
it absorbs heat.
Error:
The difference between the correct or desired value and the actual
reading or value taken.
Event input:
A programmable On/Off input used to signal peripheral
equipment or a process.
Event output:
A programmable On/Off output used to signal peripheral
equipment or a process.
Exothermic:
Gives off heat. A process is said to be exothermic when it
releases heat.
Fahrenheit:
A temperature scale with 32°F defined as the ice point and
212°F as the boiling point of water at sea level.
Filter:
A low pass filter designed to minimize display fluctuations.
Flow rate:
speed or velocity of fluid movement.
FM:
Factory Mutual Research Corp. An organization which sets indus-
trial safety standards.
FM-approved:
An instrument that meets a specific set of specifications
established by Factory Mutual Research Corp.
Form A:
Single Pole Single Throw relay that only utilizes the N.O. and
common contacts. These contacts close when the relay coil is energized.
The contacts open when power is removed from the control.
Form B:
Single Pole Single Throw relay that only utilizes the N.C. and
common contacts. These contacts will open when the relay coil is ener-
gized. The contacts will close when power is removed from the control.
Form C:
Single Pole Double Throw. Utilizes the N.O., N.C. and com-
mon contacts. The user has the option of wiring for a Form A or Form B
contact. Refer to the Form A and Form B above for more information.
fpm:
Flow velocity in feet per minute.
fps:
Flow velocity in feet per second.
Freezing point:
The temperature at which the substance goes from the
liquid phase to the solid phase.
Frequency:
The number or event occurrences or cycles over a specified
period of time.
Fuse:
A device that interrupts power in a circuit when an overload
occurs.
Fuzzy logic:
An artificial intelligence technique that allows control
decisions to be made upon approximate or incomplete information.
Fuzzy logic is a continuous decision making function that can prevent
initial overshoot and set point differentials.
Gain:
The amount of amplification used in an electrical circuit.
GIGA:
The prefix for one billion (G).
gph:
The volumetric flow rate in gallons per hour.
gpm:
The volumetric flow rate in gallons per minute.
Ground:
1. The electrical neutral line having the same potential as the
surrounding earth. 2. The negative side of dc power supply. 3. Reference
point for an electrical system.
Grounded junction:
A thermocouple junction in which the sheath and
conductors are welded together forming a completely sealed integrated
junction.
Heat:
Thermal energy expressed in Calories, Btu’s or Joules.
Heat of fusion:
The amount of energy required to change one pound of
a material from a solid to a liquid without an increase in temperature.
Expressed in Btu/lb.
Heat of vaporization:
The amount of energy required to change one
pound of a material from a liquid to a vapor without an increase in tem-
perature. Expressed in Btu/lb.
Heat sink:
1. Thermodynamic. A body which can absorb thermal ener-
gy. 2 Practical. A finned piece of metal used to dissipate the heat of solid
state components mounted on it.
Heat transfer:
The process of thermal energy flowing from a body of
high energy to a body of low energy. Means of transfer are: conduction,
the two bodies are in contact; convection, a form of conduction where
the two bodies in contact are of different phases, i.e; solid and gas; radi-
ation, all bodies emit infrared radiation
Heat treating:
A process for treating metals where heating to a specific
temperature and cooling at a specific rate changes the properties of the
metal.
Hertz (Hz):
Unit in which frequency is expressed. Synonymous with
cycles per second.
Hi-Pot test:
To apply a high voltage to an electrical conductor to test
the surrounding insulation.
Hysteresis:
In ON/OFF control, the temperature change necessary to
change the output from full ON to full OFF.
Hunting:
Oscillation or fluctuation of process temperature between set
point and process variable.
IAE:
Integrated absolute error
Ice point:
The temperature at which pure water freezes. 0°C, 32°F,
273.16K.
IE:
Integrated error
Impedance:
The total opposition in a circuit to the flow of electrical
current. Measured in ohms and represented by “Z”.
Infrared:
Or radiation is the exchange of energy by electromagnetic
waves. The infrared spectrum extends from the deep red end of the visi-
ble spectrum to the microwave region of the radio spectrum. The portion
adjacent to the visible spectrum is of importance to heating. Radiant heat
transfer can be very efficient in directing energy from the heat source to
an object.
Integral:
(see Automatic Reset).
Interchangeability error:
A measurement error that can occur if two
or more probes are used to make the same measurement. It is caused by
a slight variation in characteristics of different probes.