Temperature Controller Glossary
■ Glossary of Control Terminology
Hysteresis
ON/OFF control action turns the output ON or OFF based on the set
point. The output frequently changes according to minute
temperature changes as a result, and this shortens the life of the
output relay or unfavorably affects some devices connected to the
Temperature Controller. To prevent this from happening, a
temperature band called hysteresis is created between the ON and
OFF operations.
Control Cycle and Time-Proportioning
Control Action
The control output will be turned ON intermittently according to a
preset cycle if P action is used with a relay or SSR. This preset cycle
is called the control cycle and this method of control is called timeproportioning control action.
Temperature
Proportional band
Example:
If the control cycle is 10 s
with an 80% control
output, the ON and OFF
periods will be as
follows.
Actual temperature
Control output
Hysteresis (Reverse Operation)
Set
point
Hysteresis
ON
The higher the temperature is the shorter the ON period will be.
TON: 8 s
ON
OFF
100°C
99.2°C
OFF
Temperature
TOFF: 2 s
T T T T T T T T
T: Control cycle
TON
MV=
×100(%)
TON + TOFF
TON: ON period
TOFF: OFF period
Example: Hysteresis indicates 0.8°C.
Derivative Time
Hysteresis (Forward Operation)
Control output
Hysteresis
Derivative time is the period required for a ramp-type deviation in
derivative control (e.g., the deviation shown in the following graph)
that coincides with the control output in proportional control action.
The longer the derivative time is the stronger the derivative control
action will be.
ON
OFF
100°C
100.8°C
Temperature
Example: Hysteresis indicates 0.8°C.
Derivation
PD Action and Derivative Time
PD action
(with a short derivative time)
PD action
(with a long derivative time)
Control output
Offset
Proportional control action causes an error in the process value due
to the heat capacity of the controlled object and the capacity of the
heater. The result is a small discrepancy between the process value
and the set point in stable operation. This error is called offset. Offset
is the difference in temperature between the set point and the actual
process temperature. It may exist above or below the set point.
0
P action
D2 action
D1 action
Set point
Offset
TD1
(with a short derivative time)
Offset
Proportional
band
TD: derivative time
TD2
(with a long derivative time)
ON
OFF
Hunting and Overshooting
ON/OFF control action often involves the waveform shown in the
following diagram. A temperature rise that exceeds the set point after
temperature control starts is called overshooting. Temperature
oscillation near the set point is called hunting. Improved temperature
control is to be expected if the degree of overshooting and hunting
are low.
Hunting and Overshooting in ON/OFF Control Action
Overshooting
Set
point
Hunting
4
Integral Time
Limit Cycle Method
Integral time is the period required for a step-type deviation in
integral control (e.g., the deviation shown in the following graph) to
coincide with the control output in proportional control action. The
shorter the integral time is the stronger the integral action will be. If
the integral time is too short, however, hunting may result.
ON/OFF control begins from start point A in this method. Then obtain
the PID constants from the hunting cycle T and oscillation D.
Set point
Oscillation
PI action
(with a short integral time)
Hunting cycle
0
Time
Control output
PI action
(with a long integral time)
Readjusting PID Constants
P action
T11
(with a short integral time)
T1: Integral time
PID constants calculated in auto-tuning operation normally do not
cause problems except for some particular applications. In those
cases, refer to the following diagrams to readjust the constants.
Response to Change in the Proportional Band
Wider
T12
(with a long integral time)
It is possible to
suppress overshooting
although a
comparatively long
startup time and set
time will be required.
Set point
Deviation
PI Action and Integral Time
A
Constant Value Control
Narrower
Program Control
The process value
reaches the set point
within a comparatively
short time and keeps
the temperature stable
although overshooting
and hunting will result
until the temperature
becomes stable.
Set point
For constant value control, control is preformed at specific
temperatures.
Program control is used to control temperature for a target value that
changes at predetermined time intervals.
Auto-tuning
Response to Change in Integral Time
Wider
The set point takes
longer to reach. It is
possible to reduce
hunting, overshooting,
and undershooting although a comparatively long startup time
and set time will be required.
Set point
The PID constant values and combinations that are used for
temperature control depend on the characteristics of the controlled
object. A variety of conventional methods that are used to obtain
these PID constants have been suggested and implemented based
on actual control temperature waveforms. Auto-tuning methods make
it possible to obtain PID constants suitable to a variety of controlling
objects. The most common types of auto-tuning are the step
response, marginal sensitivity, and limit cycle methods.
Step Response Method
Set point
Narrower
The process temperature reaches the set
point within a comparatively short time although overshooting,
undershooting, and
hunting will result.
Set point
The value most frequently used must be the set point in this method.
Calculate the maximum temperature ramp R and the dead time L
from a 100% step-type control output. Then obtain the PID constants
from R and L.
R
Wider
L
Time
Set point
Response to Change in Derivative Time
External disturbance
Marginal Sensitivity Method
Narrower
A
TC
Set point
Set point
Proportional control action begins from start point A in this method.
Narrow the width of the proportional band until the temperature starts
to oscillate. Then obtain the PID constants from the value of the
proportional band and the oscillation cycle time T at that time.
External disturbance
The process value
reaches the set point
within a comparatively
short time with comparatively small
amounts of overshooting and undershooting.
Fine-cycle hunting will
result due to the
change in process value.
The process value will
take a relatively long
time to reach the set
point with heavy overshooting and undershooting.
Marginal sensitivity method
Time
5
Fuzzy Self-tuning
Self-tuning
PID constants must be determined according to the characteristics of
the controlled object for proper temperature control. The
conventional Temperature Controller incorporates an auto-tuning
function to calculate PID constants. In that case, it is necessary to
give instructions to the Temperature Controller to trigger the autotuning function. Furthermore, temperature disturbances may result if
the limit cycle is adopted. The Temperature Controller in fuzzy selftuning operation determines the start of tuning and ensures smooth
tuning without disturbing temperature control. In other words, the
fuzzy self-tuning function makes it possible to adjust PID constants
according to the characteristics of the controlled object.
Self-tuning is supported by the E5@S. Trends in temperature
changes are used to automatically calculate and set a suitable
proportional band.
Set point
• PID constants are calculated by tuning when the set point changes.
• When an external disturbance affects the process value, the PID
constants will be adjusted and kept in a specified range.
• If hunting results, the PID constants will be adjusted to suppress
hunting.
Auto-tuning with a Conventional Temperature Controller
Auto-tuning (AT) Function: A function that automatically calculates
optimum PID constants for controlled objects.
Features: (1) Tuning will be performed when the AT instruction is given.
(2) The limit cycle signal is generated to oscillate the
temperature before tuning.
Target value
AT starts
Time
Self-tuning
Fuzzy Self-tuning in 3 Modes
Temperature
oscillated.
PID gain
calculated.
PID Control and Tuning Methods for
Temperature Controllers
Model
PID
Two PID
Two PID + Fuzzy
Type of PID
E5@N (See note.)
E5@S
AT, ST**
ST*
E5ZN
AT
E5ZD
AT
C200H-TC
AT
C200H-TV
AT
C200H-PID
AT
CQM1-TC
AT
AT
ST: Fuzzy self-tuning, ST*: Self-tuning, ST**: Executed only for SP changes,
AT: Autotuning
AT instruction
Note: Not including the E5ZN
Self-tuning
Self-tuning (ST) Function: A function that automatically calculates
optimum PID constants for controlled objects.
Features: (1) Whether to perform tuning or not is determined by the
Temperature Controller.
(2) No signal that disturbs the process value is generated.
External
External
disturbance 1 disturbance 2
Target value
PID gain
calculated.
Temperature
in control
Temperature
in control
ST starts
Control Outputs
ON/OFF output
Control
output
Relay output
Contact relay output used for control methods with comparatively low switching
frequencies.
SSR output
Non-contact solid-state relay output for switching 1 A maximum.
Voltage
output
ON/OFF pulse output at 5, 12, or 24 VDC externally connected to a
high-capacity SSR. ON/OFF action is ideal for high switching frequency and
PID action is ideal for time-proportioning control action.
Current
output
Continuous 4- to 20-mA or 0- to 20-mA DC output used for driving power
controllers and electromagnetic valves. Ideal for high-precision control. A preset
linear output is produced if the load resistance falls below allowable levels.
Voltage
output
Continuous 0 to 5 or 0 to 10 VDC output used for driving pressure controllers.
Ideal for high-precision control.
Linear output
6
■ Glossary of Alarm Terminology
Alarm Operation
Heater Burnout Alarm
The Temperature Controller compares the process value and the
preset alarm value, turns the alarm signal ON, and displays the type
of alarm in the preset operation mode.
(Three phase (E5CN, E5AN, and E5EN only) and single phase)
Deviation Alarm
Many types of heaters are used to raise the temperature of the
controlled object. The CT (Current Transformer) is used by the
Temperature Controller to detect the heater current. If the heater's
power consumption drops, the Temperature Controller will detect
heater burnout from the CT and will output the heater burnout alarm.
Current value
The deviation alarm turns ON according to the deviation from the set
point in the Temperature Controller.
Setting Example
Alarm temperature is set to 110º.
Alarm set point
10°C
The alarm set point is set to 10°C.
Set point (SV)
100°C
Heater burnout
A
Heater burnout
alarm setting
0
T
Alarm value
110°C
Absolute-value Alarm
Heater current waveform (CT waveform)
The absolute-value alarm turns ON according to the alarm
temperature regardless of the set point in the Temperature
Controller.
Setting Example
The wires connected
to the Temperature
Controller have no
polarity.
Current
Transformer (CT)
Alarm set point
Alarm temperature is set to 110°C.
The alarm set point is set to 110°C.
Control output
Set point (SV)
100°C
Alarm value
110°C
Heater
Standby Sequence Alarm
It may be difficult to keep the process value outside the specified
alarm range in some cases (e.g., when starting up the Temperature
Controller), and the alarm turns ON abruptly as a result. This can be
prevented with the standby sequential function of the Temperature
Controller. This function makes it possible to ignore the process
value right after the Temperature Controller is turned ON or right
after the Temperature Controller starts temperature control. In this
case, the alarm will turn ON if the process value enters the alarm
range after the process value has been once stabilized.
Switch
Alarm Latch
The alarm will turn OFF if the process value falls outside alarm
operation range. This can be prevented if the process value enters
the alarm range and an alarm is output by holding the alarm output
until the power supply turns OFF.
Upper limit
alarm setting
Set point
Example of Alarm Output with Standby Sequence Set
Temperature rise
Upper limit
alarm setting
ON
Alarm setting
OFF
Set point
Lower-limit
alarm setting
ON
Alarm output
OFF
Temperature Drop
Upper limit
alarm setting
Set point
Lower-limit
alarm setting
ON
Alarm output
OFF
SSR Failure Alarm
LBA
(Applicable models: E5CN, E5AN, and E5EN)
The LBA (loop break alarm) is a function that turns the alarm signal
ON by assuming the occurrence of control loop failure if there is no
input change with the deviation above a certain level. Therefore, this
function can be used to detect control loop errors.
Configurable Upper and Lower Limit
Alarm Settings
(Applicable models: E5@N and E5@R)
L
H
SP
(Applicable models: E5CN)
The SSR Failure Alarm is output when an SSR short-circuit failure is
detected. A CT (Current Transformer) is used by the Temperature
Controller to detect heater current and it outputs an alarm when a
short circuit occurs.
7
■ Glossary of Temperature Sensor Terminology
Cold Junction Compensation
Input Shift
The thermo-electromotive force of the thermocouple is generated due to
the temperature difference between the hot and cold junctions.
Therefore, if the cold junction temperature fluctuates, the thermo-electromotive
force will change even if the hot junction temperature remains stable.
To negate this effect, a separate sensor is built into the Temperature Controller at
a location with essentially the same temperature as the cold junction to monitor
any changes in the temperature. A voltage that is equivalent to the resulting
thermo-electromotive force is added to compensate for (i.e., cancel) changes that
occur in the thermo-electromotive force.
Compensation for fluctuations by adding a voltage is called cold
junction compensation.
A preset point is added to or subtracted from the temperature
detected by the Temperature Sensor of the Temperature Controller to
display the process value. The difference between the detected
temperature and the displayed temperature is set as an input
compensation value.
110°C
Furnace
Terminal 20°C
Sensing point
350°C
Temperature
Controller
VT
Cold junction compensating circuit
In the above diagram, the
thermo-electromotive
force (1) VT that is
measured at the input
terminal of the
Temperature Controller is
equal to V (350, 20).
Here, V (A, B) gives the
thermo-electromotive
force when the cold
junction is A °C and the
cold junction is B °C.
Based on the law of
intermediate temperatures,
a basic behavior of
thermocouples, (2) V (A,
B) = V (A, C) - V(B, C).
120°C
Input compensation value: 10°C (Displayed value is 120°C.)
(120 − 110 = 10)
When the ambient (terminal section) temperature is
20°C, the temperature sensor inside the Temperature
Controller detects 20°C. If we add the voltage V(20, 0)
that corresponds to 20°C in the standard electromotive
force table to the right side, we get the following:
V(350, 20)
+
Thermo-electromotive
force from thermocouple
V(20, 0)
Electromotive force generated
by the cold junction
compensation circuit
If we expand the first part of formula (2) with
A = 350, B = 20, and C = 0, we get the following:
= V{(350, 0) − V(20, 0)} + V(20, 0) = V(350, 0).
V(350, 0) is the thermo-electromotive force for a cold
junction temperature of 0°C. This is the value that is
defined as the standard thermo-electromotive force
by JIS, so if we check the voltage, we can find the
temperature of the hot junction (here, 350°C).
Compensating conductor
An actual application may have a sensing point that is located far
away from the Temperature Controller.
If normal copper wires are used because the wiring length is limited
for a sensor that uses thermocouple wires or because conductors
are too expensive, a large error will occur in the temperature.
Compensating conductors are used instead of plain wires to extend
the thermocouple wires.
If compensating conductors are used within a limit temperature
range (often near room temperature), a thermo-electromotive force
that is essentially the same as the original thermocouple is
generated, so they are used to extend the thermocouple wires.
However, if compensating conductors that are suitable for the type of
thermocouple are not used, the measured temperature will not be correct.
Connection
terminal Compensating Terminal
conductor
20°C
350°C
30°C
Temperature
Controller
V (350, 30) + V (30, 20) + V (20, 0)
Thermoelectromotive
force from
thermocouple
ThermoVoltage from
electromotive cold junction
force from
compensation
compensating
conductors
= {V (350, 30) - V (30, 0)} + {V(30, 0) - V (20, 0)} + V (20, 0)
= V (350, 0)
Example of Compensating Conductor Use
8
■ Glossary of Output Terminology
Reverse Operation (Heating)
Rate of Change Limit
Control output (%)
The Temperature Controller in reverse operation will increase control
output if the process value is lower than the set point (i.e., if the
Temperature Controller has a negative deviation).
Output (%)
100
The rate of change limit for the MV sets the amount of change that
occurs per second in the MV. If the MV calculated by the
Temperature Controller changes significantly, the actual output
follows the rate of change limiter setting for MV until it approaches
the calculated value.
100
0
1s
Set point
Low
Rate of
change
limit setting
High
0
Direct Operation (Cooling)
The Temperature Controller in normal operation will increase control
output if the process value is higher than the set point (i.e., if the
Temperature Controller has a positive deviation).
Time
Change point
Dead Band
Control output (%)
The overlap band and dead band are set for the cooling output. A
negative value here produces an overlap band and a positive value
produces a dead band.
100
Dead band:
Dead band width: Positive
Output
0
Set point
Low
High
Heating
output
Heating and Cooling Control
Temperature control over a controlled object would be difficult if
heating was the only type of control available, so cooling control was
also added. Two control outputs (one for heating and one for cooling)
can be provided by one Temperature Controller.
0
Cooling
output
PV
Target value
Overlap Band:
Dead band width: Negative
Output
Heating
Temperature
Controller in
heating and
cooling
control
Controlled
object
Cooling
Heating
output
Heating and Cooling Outputs
0
Output
Cooling
output
PV
Target value
Output
Cooling Coefficient
Heating
output
PV
Target value
Heating
output
0
Cooling
output
PV
Target value
MV (Manipulated Variable) Limiter
Output (%)
The upper and lower limits for the MV limiter are set by the upper MV
and lower MV settings. When the MV calculated by the Temperature
Controller falls outside the MV limiter range, the actual output will be
either the upper or lower MV limit.
100
Upper MV limit
When adequate control characteristics cannot be obtained using the
same PID constants, such as when the heating and cooling
characteristics of the controlled object vary significantly, adjust the
proportional band on the cooling side (cooling side P) using the
cooling coefficient until heating and cooling side control are
balanced. P on the heating and cooling control sides is calculated
from the following formula.
Heating side P = P
Cooling side P = Heating side P x cooling coefficient
For cooling side P control when heating side characteristics are
different, multiply the heating side P by the cooling coefficient.
Heating Side P × 0.8
Lower MV limit
0
Output
0
Cooling
output
Heating side
P × 1.0
PV
0
Heating
side P
Cooling
side P
PV
Heating Side P × 1.5
Output
Output (%)
With heating and cooling control, the cooling MV is treated as a
negative value. Generally speaking then, the upper limit (positive
value) is set to the heating output and the lower limit (negative value)
is set to the cooling output as shown in the following diagram.
100
Upper MV limit
Heating side P × 1.0
Lower MV limit
Heating
output
0
Cooling
output
Target value
PV
Heating
side P
0
Cooling
side P
PV
9
Positioning-Proportioning Control
Transfer Output
This is also called ON/OFF servo control. When a Control Motor or
Modutrol Motor with a valve is used in this control system, a
potentiometer for open/close control reads the degree of opening
(position) of the control valve, outputs an open and close signal, and
transmits the control output to Temperature Controller. The
Temperature Controller outputs two signals: an open and close
signal. OMRON uses floating control. This means that the
potentiometer does not feed back the control valve position and
temperature can be controlled with or without a potentiometer.
A Temperature
Controller with current
output independent
from control output is
available. The process
value or set point
within the available
temperature range of
the Temperature
Controller is
converted into 4- to
20-mA linear output
that can be input into
recorders to keep the
results of temperature
control on record.
Open
Controlled
object
M
Close
Recorder
Temperature Sensor
20 mA
output
Temperature
Controller in
positionproportioning
control
Temperature
Controller with
transfer output
12 mA
4 mA
Potentiometer
reading the
control valve
position
0°C
Lower limit
100
200
Process value
Upper limit
■ Glossary of Setting Terminology
Set Limit
Set Point (SP) Ramp
The set point range depends on the Temperature Sensor and the set
limit is used to restrict the set point range. This restriction affects the
transfer output of the Temperature Controller.
The SP ramp function controls the target value change rate with the
variation factor. Therefore, when the SP ramp function is enabled,
some range of the target value will be controlled if the change rate
exceeds the variation factor as shown on the right.
−200°C
1300°C K
SP
SP ramp
Target value
after changing
0°C
500°C
SP ramp
set value
Possible setting range
Multiple Set Points
Two or more set points independent from each other can be set in
the Temperature Controller in control operation.
Setting Memory Banks
The Temperature Controller stores a maximum of eight groups of
data (e.g., set value and PID constant data) in built-in memory banks
for temperature control. The Temperature Controller selects one of
these banks in actual control operation.
Time
Change point
Remote Set Point (SP) Input
For a remote set point input, the Temperature Controller uses an
external input ranging from 4- to 20-mA for the target temperature.
When the remote SP function is enabled, the 4- to 20-mA input
becomes the remote set point.
Event Input
Memory Bank 00
Set value
P constant
I constant
D constant
SP ramp
time unit
Target value
before changing
Bank 1
Bank 7
An event input is an external signal that can be used to control
various actions, such as target value switching, equipment or
process RUN/STOP, and pattern selection.
Input Digital Filter
The input digital filter parameter is used to set the time constant of
the digital filter. Data that has passed through the digital filter
appears as shown in the following diagram.
Select bank 1.
PV before passing through the filter
A
Temperature control using
constants in memory bank 1
PV after passing through the filter
0.63 A
(Time
constant)
Time
Input digital filter
10
Temperature Sensor Glossary
■ Temperature Sensor Types and Features
Type
Advantages
Disadvantages
Element
type
The electrical resistance of the
• High precision • Expensive
JPt100
metal used by platinum
• Easily
Pt100
resistance thermometers has a
influenced by
fixed relationship to the
lead wire
temperature. Therefore, a
resistance
platinum wire with extremely high
(OMRON
purity is used for the resistor.
minimizes
Temperature Characteristics
influence by
using a 3conductor
system.)
• Slow thermal
response
• Low resistance
100
to shock and
0
Temperature
vibration
Resistance (Ω)
Platinum
resistance
thermometer
Principle and characteristics
Thermocouple
Thermocouple temperature
sensors are constructed using
two dissimilar metals that are
joined together. The junctions are
called the measuring junction and
the reference junction (output
terminal side). A
thermoelectromotive force is
generated between the junctions
with a fixed correlation to the
temperature providing the
difference in temperature.
Therefore, the temperature at the
measuring junction can be
determined from the
thermoelectromotive force when
a fixed temperature is maintained
at the reference junction.
Thermocouple temperature
sensors are capable of
measuring the highest
temperatures among contact
temperature sensors by using this
measurement method.
• Broad
temperature
range
• Hightemperature
measurement
• High
resistance to
shock and
vibration
• Fast thermal
response
• Compensating K (CA)
conductors are J (IC)
required when R (PR)
extending the
lead wires
Class
JIS Standard
Class
Tolerance
Class A
± (0.15+0.002⏐ t ⏐) °C
Class B
± (0.3+0.005⏐ t ⏐) °C
Note: ⏐ t ⏐ represents the absolute value of the
temperature range.
JIS Standard for Thermocouples
Material Model Temperacode
name ture range
Class
Tolerance
(See note.)
R
PR
0°C to
1,600°C
Class 2 ±1.5°C or
(0.25) ±0.25% of
measured
temperature
K
CA
0°C to
1,200°C
Class 2 ±2.5°C or
(0.75) ±0.75% of
measured
temperature
J
IC
0°C to
750°C
Class 2 ±2.5°C or
(0.75) ±0.75% of
measured
temperature
Note: The tolerance is either the value in °C
or %, whichever is larger.
Thermoelectromotive force
(mV)
Standard Thermoelectromotive Force
0
Thermistor
0
Temperature
Resistance (kΩ)
Temperature Characteristics
• Fast thermal
• Limited
Thermistor
response
temperature
range
• Small error
JIS Standard Class 1
due to lead
• Low resistance
wire resistance to shock
Measured
temperature
Temperature
Tolerance
−50 to 100°C
±1°C max.
100 to 350°C
±1% max. of measured
temperature
3
■ Pt100 and JPt100
In January 1, 1989, the JIS standard for platinum resistance thermometers (Pt100) was revised to incorporate the IEC (International
Electrotechnical Commission) standard. The new JIS standard was established on April 1, 1989. Platinum resistance thermometers prior to the
JIS standard revision are distinguished as JPt100. Therefore, make sure that the correct platinum resistance thermometer is being used.
• The following table shows the differences in appearance of the Pt100 and JPt100.
Classification by model
Pt100
(New JIS standard)
E52-P15AY
Pt100 is indicated as P.
JPt100
(Previous JIS standard)
E52-PT15A
JPt100 is indicated as PT.
Note: OMRON discontinued production of JPt100 Sensors in March of 2003.
600
500
JPt100 input
400
Pt100 sensor
300
200
● Indicated Temperature when Connecting JPt100
Sensor to Pt100 Input
Controller indicated temperature (°C)
Controller indicated temperature (°C)
● Indicated Temperature when Connecting Pt100 Sensor
to JPt100 Input
600
500
JPt100 sensor
400
200
100
100
0
0
−100
−100
0
100
200
300
400
500
600
Measured temperature (°C)
Pt100 input
300
−100
−100
0
100
200
300
400
500
600
Measured temperature (°C)
4
■ Temperature Sensor Construction
Sheathed
Features • Compared with standard models, these sensors have high
resistance to vibration and shock.
• The finished outer diameter is extremely slim enabling easy
insertion in small sensing objects, and low heat capacity
enables fast response to changes in temperature.
• The sheathed tubing is flexible, enabling insertion and
measurement within complex machinery.
• The airtight construction provides high sensitivity and prevents
oxidation, for superior heat resistance and durability.
Internal
structure
Sheathed platinum resistance thermometer
MgO
Stainless steel
Element protective tubing Nickel lead
Standard
• Compared with the sheathed models, the thick tubing diameter
provides strength and durability.
• Slow response speed.
Standard platinum resistance thermometer
Leaf spring
Protective tubing
Element
Sheathed
thermocouple
Stainless steel
protective tubing
Standard thermocouple
Measuring junction
Protective tubing
MgO insulation
Element
■ Thermocouple Measuring Junction Construction
Non-grounded models
Grounded models
Features • Fully isolated measuring junction and protective tubing
• Soldered ends of measuring junction protective tubing.
• Response is inferior to grounded models, but noise resistance is • Fast response but noise resistance is low.
high.
• High productivity at a low cost.
• Widely used for general-purpose applications.
Internal
construction
Non-grounded model
Grounded model
The protective tubing and thermocouple are insulated.
There is no insulation between the protective tubing and
thermocouple.
5
■ Terminal Block Appearance
Exposed lead wires
Exposed terminals
Features Lead wires directly extend from protective
tubing, enabling low-cost manufacturing
without requiring more space.
➜ For building into machines
Enclosed terminals
Construction uses exposed terminal screws Construction with enclosed terminal screws
for easy maintenance.
enables broad range of applications.
➜ For general-purpose indoor use
➜ For indoor industrial equipment
Appearance
Permis- • Sleeve Standard: 0 to +70°C
Permissible temperature in dry air for
sible
Heat Resistive: 0 to +100°C
terminal box: 0 to +100°C
tempera- • Lead wire (platinum resistance
ture in
thermometer)
dry air
Standard (vinyl-covered): −20 to +70°C
Heat resistive (glass-wool-covered with
stainless-steel external shield): 0 to 180 °C
• Lead wire (compensating conductor)
Standard (vinyl-covered): −20 to +70°C
Heat resistive (glass-wool-covered with
stainless-steel external shield): 0 to 150 °C
Permissible temperature in dry air for
terminal box: 0 to +90°C
■ Temperature Sensor Thermal Response
A temperature sensor has a thermal
capacity. That means that time is required
from when the temperature sensor touches
the sensing object until the temperature
sensor and sensing object reach the same
temperature.
For a thermocouple, the response time is
the time required for the temperature sensor
to reach 63.2% of temperature of the
sensing object. For a resistance
thermometer, the response time is the time
to reach 50% of temperature of the sensing
object.
● Thermal Response of Sheathed Temperature Sensors (Reference Value)
Protective tubing: ASTM316L
Static water, room temperature to 100 °C
Test conditions
Protective tubing 1.0 dia.
dia. (mm)
1.6 dia.
3.2 dia.
4.8 dia.
6.4 dia.
8 dia.
Indicated value
Thermo- Thermo- Thermo- Platinum Thermo- Platinum Thermo- Platinum Platinum
couple couple couple
resiscouple
resiscouple
resisresistance
tance
tance
tance
thermomthermomthermom- thermometer
eter
eter
eter
Response time
1 s max. 1 s max. 1 s
2.5 s
1.8 s
4.2 s
4s
9.9 s
12.9 s
● Standard Temperature Sensors
Thermal Response of Standard Thermocouple (Reference Value)
Protective tubing: SUS316
Test conditions
Static water
Protective tubing
dia. (mm)
Dry air, room temperature to 100°C
12 dia. (thermocouple element dia: 1.6 mm)
Indicated value
Room
temperature to
100°C
Response time
55 s
100°C to room
temperature
56 s
Static air
6 min. 50 s
Fed air:
1.5 m/s
2 min. 2 s
Fed air:
3 m/s
1 min. 43 s
Thermal Response of Platinum Resistance Thermometer (Reference Value)
Protective tubing: SUS316
Test conditions
Static water, room
temperature to 100°C
Protective tubing
dia. (mm)
10 dia.
Indicated value
Response time
23.6 s
6
■ Vibration and Shock Resistance
The testing standards for temperature
sensors specified by JIS are provided in the
tables on the right. Refer to these standards
and provide sufficient margins for the
application conditions.
● Vibration Resistance
Thermocouple
Test item
(Conforms to JIS C1602-1995)
Frequency
(Hz)
Double
amplitude
(mm)
Testing tim (min)
Sweeps
Vibration direction
Destruction
Resonance test
30 to 100
0.05
2
---
Fixed frequency
durability test
100
0.02
---
60
Two axis directions
including length
direction
Note: This test is not performed for Sensors with non-metal protective tubing.
Fixed frequency durability tests are conducted at 70 Hz when the resonance point is 100 Hz.
Platinum Resistance Thermometer
10 to 150
(Conforms to JIS C1604-1997)
Acceleration (m/s2)
Frequency (Hz)
10 to 20
Sweeps per minute
No. of sweeps
2
10
Note: This test is not performed for Sensors with non-metal protective tubing.
● Shock Resistance
Holding the test product on its side, the product is then dropped from a height of 250 mm onto a
steel plate 6 mm thick placed on a hard floor. This process is repeated 10 times, after which the
product is checked for electrical faults in the measuring junctions and terminal contacts. This
test is not performed, however, on products with non-metal protective tubing (conforms to JIS
C1602-1995 and JIS C1604-1997).
■ Permissible Temperature in Dry Air
The permissible temperature is the
temperature limit for continuous usage in
air.
For thermocouples with protective tubes,
the permissible temperature is determined
collectively by the type of thermocouple,
the element diameters, the insulating tube
material, protective tube materials, heat
resistance, and other factors. The
permissible temperature is also called the
usage limit.
Generally speaking, lowering the usage
temperature will increase the life of a
thermocouple. Allow sufficient leeway in the
permissible temperature.
● Sheathed
● Standard
Thermocouple Permissible Temperature
in Dry Air
Thermocouple Permissible Temperature
in Dry Air
M: Protective tubing material
D: Protective tubing diameter (mm)
M: Protective tubing material
D: Protective tubing diameter (mm)
Element M
K (CA)
ASTM316L
J (IC)
ASTM316L
Element K (CA)
M SUS310S
D
K (CA)
SUS316
J (IC)
SUS316
1 dia.
650°C
450°C
D
1.6 dia.
650°C
450°C
10 dia.
750°C
750°C
450°C
3.2 dia.
750°C
650°C
12 dia.
850°C
850°C
500°C
4.8 dia.
800°C
750°C
15 dia.
900°C
850°C
550°C
1,000°C
900°C
600°C
6.4 dia.
800°C
750°C
22 dia.
8.0 dia.
900°C
750°C
Permissible Temperature in Dry Air
Element M
R
PT1
R
PT0
D
15 dia.
JIS symbol
1,400°C
Type
PT0
Protective tubing: Special
ceramic
PT1
Protective tubing: Ceramic
Cat. 1
7
Reference Material for Temperature Sensors
■ Thermocouple Standard Potential Difference
Thermocouples generate voltage according to the temperature difference. The potential difference is prescribed by Japanese Industrial Standards
(JIS).
The following chart gives the potential difference for R, S, K, and J thermocouples when the temperature of the reference junction is 0°C.
JIS C 1602-1995 (Unit: μV)
(Standards Published in 1995)
Category
R standard potential
difference
S standard potential
difference
K standard potential
difference
J standard potential
difference
Temperature (°C)
0
0
0
10
54
20
111
30
40
50
171
232
296
60
70
363
431
80
501
90
573
100
647
723
800
879
959
1,041
1,124
1,208
1,294
1,381
200
1,469
1,558
1,648
1,739
1,831
1,923
2,017
2,112
2,207
2,304
300
2,401
2,498
2,597
2,696
2,796
2,896
2,997
3,099
3,201
3,304
400
3,408
3,512
3,616
3,721
3,827
3,933
4,040
4,147
4,255
4,363
500
4,471
4,580
4,690
4,800
4,910
5,021
5,133
5,245
5,357
5,470
600
5,583
5,697
5,812
5,926
6,041
6,157
6,273
6,390
6,507
6,625
700
6,743
6,861
6,980
7,100
7,220
7,340
7,461
7,583
7,705
7,827
800
7,950
8,073
8,197
8,321
8,446
8,571
8,697
8,823
8,950
9,077
900
9,205
9,333
9,461
9,590
9,720
9,850
9,980
10,111
10,242
10,374
1,000
10,506
10,638
10,771
10,905
11,039
11,173
11,307
11,442
11,578
11,714
1,100
11,850
11,986
12,123
12,260
12,397
12,535
12,673
12,812
12,950
13,089
1,200
13,228
13,367
13,507
13,646
13,786
13,926
14,066
14,207
14,347
14,488
1,300
14,629
14,770
14,911
15,052
15,193
15,334
15,475
15,616
15,758
15,899
1,400
16,040
16,181
16,323
16,464
16,605
16,746
16,887
17,028
17,169
17,310
1,500
17,451
17,591
17,732
17,872
18,012
18,152
18,292
18,431
18,571
18,710
1,600
18,849
18,988
19,126
19,264
19,402
19,540
19,677
19,814
19,951
20,087
1,700
20,222
20,356
20,488
20,620
20,749
20,877
21,003
---
---
---
0
0
55
113
173
235
299
365
433
502
573
100
646
720
795
872
950
1,029
1,110
1,191
1,273
1,357
200
1,441
1,526
1,612
1,698
1,786
1,874
1,962
2,052
2,141
2,232
300
2,323
2,415
2,507
2,599
2,692
2,786
2,880
2,974
3,069
3,164
400
3,259
3,355
3,451
3,548
3,645
3,742
3,840
3,938
4,036
4,134
500
4,233
4,332
4,432
4,532
4,632
4,732
4,833
4,934
5,035
5,137
600
5,239
5,341
5,443
5,546
5,649
5,753
5,857
5,961
6,065
6,170
700
6,275
6,381
6,486
6,593
6,699
6,806
6,913
7,020
7,128
7,236
800
7,345
7,454
7,563
7,673
7,783
7,893
8,003
8,114
8,226
8,337
900
8,449
8,562
8,674
8,787
8,900
9,014
9,128
9,242
9,357
9,472
1,000
9,587
9,703
9,819
9,935
10,051
10,168
10,285
10,403
10,520
10,638
11,830
1,100
10,757
10,875
10,994
11,113
11,232
11,351
11,471
11,590
11,710
1,200
11,951
12,071
12,191
12,312
12,433
12,554
12,675
12,796
12,917
13,038
1,300
13,159
13,280
13,402
13,523
13,644
13,766
13,887
14,009
14,130
14,251
1,400
14,373
14,494
14,615
14,736
14,857
14,978
15,099
15,220
15,341
15,461
1,500
15,582
15,702
15,822
15,942
16,062
16,182
16,301
16,420
16,539
16,658
1,600
16,777
16,895
17,013
17,131
17,249
17,366
17,483
17,600
17,717
17,832
1,700
17,947
18,061
18,174
18,285
18,395
18,503
18,609
---
---
---
0
0
397
798
1,203
1,612
2,023
2,436
2,851
3,267
3,682
100
4,096
4,509
4,920
5,328
5,735
6,138
6,540
6,941
7,340
7,739
200
8,138
8,539
8,940
9,343
9,747
10,153
10,561
10,971
11,382
11,795
300
12,209
12,624
13,040
13,457
13,874
14,293
14,713
15,133
15,554
15,975
400
16,397
16,820
17,243
17,667
18,091
18,516
18,941
19,366
19,792
20,218
500
20,644
21,071
21,497
21,924
22,350
22,776
23,203
23,629
24,055
24,480
600
24,905
25,330
25,755
26,179
26,602
27,025
27,447
27,869
28,289
28,710
700
29,129
29,548
29,965
30,382
30,798
31,213
31,628
32,041
32,453
32,865
800
33,275
33,685
34,093
34,501
34,908
35,313
35,718
36,121
36,524
36,925
900
37,326
37,725
38,124
38,522
38,918
39,314
39,708
40,101
40,494
40,885
1,000
41,276
41,665
42,053
42,440
42,826
43,211
43,595
43,978
44,359
44,740
1,100
45,119
45,497
45,873
46,249
46,623
46,995
47,367
47,737
48,105
48,473
1,200
48,838
49,202
49,565
49,926
50,286
50,644
51,000
51,355
51,708
52,060
1,300
52,410
52,759
53,106
53,451
53,795
54,138
54,479
54,819
---
---
0
0
507
1,019
1,537
2,059
2,585
3,116
3,650
4,187
4,726
100
5,269
5,814
6,360
6,909
7,459
8,010
8,562
9,115
9,669
10,224
200
10,779
11,334
11,889
12,445
13,000
13,555
14,110
14,665
15,219
15,773
300
16,327
16,881
17,434
17,986
18,538
19,090
19,642
20,194
20,745
21,297
400
21,848
22,400
22,952
23,504
24,057
24,610
25,164
25,720
26,276
26,834
500
27,393
27,953
28,516
29,080
29,647
30,216
30,788
31,362
31,939
32,519
600
33,102
33,689
34,279
34,873
35,470
36,071
36,675
37,284
37,896
38,512
700
39,132
39,755
40,382
41,012
41,645
42,281
42,919
43,559
44,203
44,848
800
45,494
46,141
46,786
47,431
48,074
48,715
49,353
49,989
50,622
51,251
900
51,877
52,500
53,119
53,735
54,347
54,956
55,561
56,164
56,763
57,360
1,000
57,953
58,545
59,134
59,721
60,307
60,890
61,473
62,054
62,634
63,214
1,100
63,792
64,370
64,948
65,525
66,102
66,679
67,255
67,831
68,406
68,980
1,200
69,553
---
---
---
---
---
---
---
---
---
9
■ Reference Temperature Characteristics for Platinum Resistance
Thermometers (Ω)
Pt100
Temperature (°C)
JIS C 1604-1997
−100
0
60.26
−10
−20
−0
Temperature (°C)
100.00
0
56.19
96.09
52.11
92.16
−30
48.00
88.22
−40
43.88
−50
39.72
−60
−70
0
100
200
300
400
500
600
700
800
100.00
138.51
175.86
212.05
247.09
280.98
313.71
345.28
375.70
10
103.90
142.29
179.53
215.61
250.53
284.30
316.92
348.38
378.68
20
107.79
146.07
183.19
219.15
253.96
287.62
320.12
351.46
381.65
30
111.67
149.83
186.84
222.68
257.38
290.92
323.30
354.53
384.60
84.27
40
115.54
153.58
190.47
226.21
260.78
294.21
326.48
357.59
387.55
80.31
50
119.40
157.33
194.10
229.72
264.18
297.49
329.64
360.64
390.48
35.54
76.33
60
123.24
161.05
197.71
233.21
267.56
300.75
332.79
363.67
---
31.34
72.33
70
127.08
164.77
201.31
236.70
270.93
304.01
335.93
366.70
---
−80
27.10
68.33
80
130.90
168.48
204.90
240.18
274.29
307.25
339.06
369.71
---
−90
22.83
64.30
90
134.71
172.17
208.48
243.64
277.64
310.49
342.18
372.71
---
−100
18.52
60.26
100
138.51
175.86
212.05
247.09
280.98
313.71
345.28
375.70
---
JPt100
Temperature (°C)
JIS C 1604-1997
−100
−0
Temperature (°C)
0
100
200
177.13
300
213.93
400
249.56
500
0
59.57
100.00
0
100.00
139.16
284.02
−10
55.44
96.02
10
103.97
143.01
180.86
217.54
253.06
---
−20
51.29
92.02
20
107.93
146.85
184.58
221.15
256.55
---
−30
47.11
88.01
30
111.88
150.67
188.29
224.74
260.02
---
−40
42.91
83.99
40
115.81
154.49
191.99
228.32
263.49
---
−50
38.68
79.96
50
119.73
158.29
195.67
231.89
266.94
---
−60
34.42
75.91
60
123.64
162.08
199.35
235.45
270.38
---
−70
30.12
71.85
70
127.54
165.86
203.01
238.99
273.80
---
−80
25.80
67.77
80
131.42
169.63
206.66
242.53
277.22
---
−90
21.46
63.68
90
135.30
173.38
210.30
246.05
280.63
---
−100
17.14
59.57
100
139.16
177.13
213.93
249.56
284.02
---
10
■ Standard Temperature Characteristics for Element-interchangeable
Thermistors
The following chart gives the temperature characteristics for low-cost thermistors used in the E5C2, E5L, and E5CS.
JIS C 1611-1975
Nominal resistance
6 kΩ (0°C)
30 kΩ (0°C)
3 kΩ (100°C)
0.55 kΩ (200°C)
4 kΩ (200°C)
8 kΩ (200°C)
Ambient operating
temperature
−50 to 100°C
0 to 150°C
50 to 200°C
100 to 250°C
250 to 300°C
200 to 350°C
Temperature
(°C)
Deviation in Resistance Resistance Resistance Resistance Resistance Resistance Resistance Resistance Resistance Resistance Resistance Resistance
characteristics
deviation
deviation
deviation
deviation
deviation
deviation
and resistance
−50
75.36 kΩ
±4.28 kΩ
−40
42.90
±2.28
−30
25.23
±1.26
−20
15.21
±0.72
77.07 kΩ
−10
9.414
±0.422
47.41
0
6.000
±0.261
30.00
±1.35 kΩ
10
3.934
±0.158
19.49
±0.80
20
2.637
±0.100
12.97
±0.50
30
1.812
±0.065
8.828
±0.323
28.05 kΩ
40
1.266
±0.043
6.140
±0.212
19.31
50
904.2 Ω
±29.0 Ω
4.356
±0.144
13.57
±0.47 kΩ
60
657.7
±20.0
3.147
±0.098
9.717
±0.310
70
487.0
±14.0
2.317
±0.068
7.081
±0.214
80
365.7
±10.0
1.734
±0.048
5.243
±0.151
12.66 kΩ
90
278.9
±7.2
1.318
±0.035
3.939
±0.108
8.626
±5.5
100
215.6
1.017
±0.026
3.000
±0.080
6.281
±0.194 kΩ
110
168.4
794.0 Ω
±18.9 Ω
2.314
±9.058
4.649
±0.134
120
133.3
627.7
±14.2
1.805
±0.043
3.495
±0.096
130
501.7
±10.8
1.424
±0.033
2.664
±0.069
23.06 kΩ
140
405.2
±8.3
1.134
±0.025
2.056
±0.051
17.44
150
330.5
±5.6
912.1 Ω
±19.5 Ω
1.610
±0.039
13.33
±0.35 kΩ
160
272.0
734.9
±15.4
1.273
±0.029
10.29
±0.26
170
225.8
596.1
±12.1
1.017
±0.022
8.027
±0.194
180
486.7
±9.6
823.6 Ω
±17.0 Ω
6.312
±0.147
13.39 kΩ
190
400.0
±7.7
669.3
±13.2
5.006
±0.113
10.29
200
330.6
±6.2
550.0
±10.5
4.000
±0.087
8.000
±0.190 kΩ
210
455.4
±8.3
3.221
±0.068
6.305
±0.146
220
380.6
±6.7
2.611
±0.053
5.015
±0.111
230
319.2
±5.4
2.131
±0.042
4.014
±0.086
240
269.9
±4.4
1.751
±0.034
3.240
±0.076
250
230.0
±3.5
1.445
±0.027
2.634
±0.054
260
196.8
1.202
±0.022
2.156
±0.042
270
169.5
1.004
±0.018
1.779
±0.033
280
842.5 Ω
±14.4 Ω
1.474
±0.027
290
710.8
±11.8
1.228
±0.022
300
602.4
±9.7
1.030
±0.018
310
512.8
868.1 Ω
±14.3 Ω
320
438.3
738.2
±11.7
330
631.0
±9.6
340
542.2
±7.9
350
468.0
±6.8
Thermistor constant B
3,390 K
3,450 K
3,894 K
4,300 K
5,133 K
5,559 K
Note: Amount of change in resistance per degree C in the resistance deviation and specified temperature.
11
Connection Examples between Digital Temperature Controllers and SSRs
Digital Temperature Controller
CSM_Connecting_TS_SSR_CG_E_3_1
SSRs
Load
+
+
Heater
Voltage output
terminal
(for driving SSR)
INPUT
−
Load power supply
LOAD
−
Directly connectable
Digital Temperature Controllers with voltage output of 40 mA at 12 VDC
E5EC/E5AC
E5EC-T/E5AC-T
Number of
Connectable
SSRs in parallel
E5AN-H/E5EN-H
G3PF (SSR with built-in Current Transformer)
25 A or 35 A at 240/480 VAC
8
Rated input voltage:
12 to 24 VDC
4
With built-in CT. Detects
heater burnout and SSR
short-circuit failures.
*1
E5AR/E5AR-T
E5ER/E5ER-T
5
G3PE (Single-phase)
15 A, 25 A, 35 A, or 45 A at 240/480 VAC
Rated input voltage:
12 to 24 VDC
3
*2
Extremely thin Relays
integrated with heat sinks.
G3PE (Three-phase)
15 A, 25 A, 35 A, or 45 A at 240/480 VAC
4
Rated input voltage:
12 to 24 VDC
2
Slim design with 3-phase
output and built-in heat sinks.
Digital Temperature Controllers with voltage output of 21 mA at 12 VDC
E5CC/-T
Note: Refer to your OMRON website for details.
E5CN-H
*3
5
E5CC-U
E5GC
3
*4
STOP
TUNE
E5CB
E5CS Series
*5
5
*6
PWR
RUN
ERR
ALM
89AB
EJ1N-
3 4 5 67
ON
1 2 3 4 5 6 7 8
SW2
2
1
● Calculating the Number of Connectable SSRs in Parallel
(A): The maximum load current for the voltage output (for
driving SSR) of each Temperature Controller.
(B): SSR input current
(A) ÷ (B) = Number of connectable SSRs
*1.
*2.
*3.
*4.
*5.
*6.
G3NA
5 A, 10 A, 20 A, 40 A, 75 A, or 90 A at 240 VAC
10 A, 20 A, 40 A, 75 A, or 90 A at 480 VAC
Standard model with
screw terminals.
G3NE
5 A, 10 A, or 20 A at 240 VAC
COM1
COM2
COM3
CDE
F 0 12
SW1
Rated input voltage:
5 to 24 VDC
or 12 to 24 VDC
Thin Relays integrated with
heat sinks.
Rated input voltage:
5 to 24 VDC
3
EJ1
G3PA
10 A, 20 A, 40 A, or 60 A at 240 VAC
20 A, 30 A, or 50 A at 480 VAC
Rated input voltage:
12 VDC
Compact, low-cost model
with faston terminals.
G3PH
75 A or 150 A at 240/480 VAC
8
Rated input voltage:
Two G3PE-BL SSRs can be connected.
5 to 24 VDC
4
One G3PE-BL SSR can be connected.
Two G3PA-BL SSRs can be connected.
For high-power heater
One G3PA-BL SSR can be connected.
control.
Two of the -UTU models of the G3NA SSRs can be connected.
One of the -UTU model of the G3NA SSRs can be connected. Four of the 480-VAC models of the G3NA SSRs can be connected.
1