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SIMIREL: Relays for All Applications. Temperature Monitoring Guidelines for SIMIREL 3RS10/3RS11. Overview. Overview: The Definition of Temperature. Temperature: One of the most important industrial measurements.

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Simirel relays for all applications

SIMIREL: Relays for All Applications

Temperature Monitoring Guidelines

for

SIMIREL

3RS10/3RS11

Overview


Overview the definition of temperature

Overview: The Definition of Temperature

Temperature:

One of the most important industrial measurements.

Physically speaking, heat is a means to measure the energy within a body. Such energy is stored in the disordered molecular and atomic movements of a body and increases with a simultaneous increase in temperature.

The unit of measurement for temperature is Kelvin [K]. At 0°K (-273.5°C), all molecules within a body are at rest, i.e. its heat capacity is zero. The measurement of absolute temperature is generally stated in [°C] and temperature differences are stated in [K].

Thus, with many applications, temperature monitoring equals the (energy) monitoring of materials and system components.

Overview


Overview the most important sensors

Overview: The Most Important Sensors

  • Sensors:

  • Thermocouples: Two interconnected metals which deliver a thermoelectric voltage independent of the ambient temperature. This voltage is a direct means of measurement for the difference between the measuring junction temperature T1 and the reference junction temperature T2.

  • Resistance sensors: These sensors change their resistance independent of the ambient temperature. They are generally made of platinum wire which is either fixed to a ceramic mould body (thin-film resistor) or is coiled onto a support within an oversheath. Resistance sensors are available as PTC resistors or as NTC resistors.

Sensors for electrical temperature monitoring can be divided into:

Overview


Thermocouples

Thermocouples

Mode of Operation

Overview

Reference Junction

Compensation

Application Areas

Colour Codes

Thermocouples


The seebeck effect thermoelectric effect regarding thermoelectric couples

The Seebeck Effect: Thermoelectric Effect Regarding Thermoelectric Couples

  • A thermocouple generates a thermoelectric voltage independent of the used materials and the temperature difference between the measuring point and the reference junction.

  • No absolute temperatures can be measured with thermocouples.

  • The measuring point is the point at which the two metals are soldered, welded or twisted.

  • The reference junction is the point at which the two different conductors are connected to a further metal (e.g. copper).

Thermocouples

NiCr

Reference junction

Umeas

T1

T2

Ni

Measuring point

Umeas = Uth T1 -Uth T2

The thermoelectric effect is the generation of an electromotive force (EMF) by ways of a temperature difference between the two connection junctions of two different metals which are part of a joint electric circuit.


Measuring absolute temperatures with the help of reference junction compensation

Measuring Absolute Temperatures with the Help of “Reference Junction Compensation”

  • A “mere” temperature difference measurement between the measuring point and the reference junction can be carried out with the help of the thermoelectric effect.

  • To be able to evaluate the absolute temperature at the measuring junction, the ambient temperature of the reference junction must be established and added (e.g. with the help of a PT100).

Thermocouples

NiCr

Internal

reference junction

T2

T1

Ni

Measuring point

PT100

Tabs= T1 (from Umeas = Uth T1 -Uth T2 ) + T2 (from RPT100 )

  • All SIMIREL 3RS11 monitoring relays for thermocouples are already equipped with an internal reference junction compensation.

  • Thus, the ambient temperature of the evaluation device need not be taken into account.

  • A length extension of the thermoconductors is only permissible with the use of suitable conductors.


Overview thermocouples

Long-term

Short-term

100

500

1000

K

42

Nickel-Chrome / Nickel-Aluminium

-180°C up to 1350

°C

0°C up to 1100

°C

43

39

-250°C up to 400°C

-185°C up to 300°C

Copper / Copper-Nickel

-

46

-

T

54

-180°C up to 750°C

59

56

J

20°C up to 700°C

Iron / Copper-Nickel

39

0°C up to 1100

°C

-270°C up to 1300

°C

30

Nickel-Chrome-Silicium / Nickel-Silicium

N

38

-40°C up to 900°C

E

Nickel-Chrome / Copper-Nickel

-

68

81

0°C up to 800°C

Overview:Thermocouples

DIN EN 60584-2 (1994), IEC 584-2 (1992)

Element/ alloy

Voltage changes per °C in µV at °C:

Applicationtemperatures

Properties / Notes

Thermocouples

  • The most commonly used thermocouple

  • For oxidising atmospheres with a large application temperature range

  • Large hysteresis

  • Rarely used

  • For low application temperatures

  • Good properties concerning high humidity

  • Commonly used in the plastics industry

  • Also used with exposed measuring junctions in reduced atmospheres

  • Corrodes with low temperatures,

  • oxidises with high temperatures

  • (Still) rarely used

  • Extremely stable output signal

  • High resistance against temperature change strains

  • Largest thermoelectric voltage per °C

  • Also used with exposed measuring junctions within a vacuum or slightly oxidising atmospheres


Application areas of thermocouple and extension wires

Application Areas of Thermocouple and Extension- Wires

DIN 43722 (1994), IEC 584-3 (1989)

International identification letters

Max. temperature of the conducting wires

Temperature range of performance

Properties / Notes

K

Thermo-

conductor KX

900°C

-25°C up to +200°C

The extension wire is made of the same material as the thermoelectric couple, i.e. thermal faults are minimized.

Thermocouples

Extension conductor KCB

900°C

0°C up to +100°C

Cost-favorable alternative for applications within these temperature limits (Copper - Copper/Nickel).

T

Thermo-

conductor TX

300°C

-25°C up to +200°C

The extension wire is made of the same material as the Thermocouple. Extension wire is not accounted for (cost-favorable).

J

Thermo-

conductor JX

500°C

-25°C up to +200°C

The extension wire is made of the same material as the Thermocouple. Extension conductors are not accounted for (cost-favorable).

N

Thermo-

conductor NX

900°C

-25°C up to +200°C

The extension wire is made of the same material as the thermocouple.

Extension conductor NC

900°C

0°C up to +150°C

Extension wires are not normally used. The accuracy advantage of this thermocouples would be lost.

E

Thermo-

conductor EX

500°C

-25°C up to +200°C

The extension wire is made of the same material as the thermocouple. Extension conductors are not accounted for.


Color codes for thermocouples and extension wires

Color Codes for Thermocouples and Extension Wires

DIN 43722 (1994), IEC 584-3 (1989)

ANSI MC96.1

International identification letters

German and international color codes

Intern. color codes for intrinsically safe

electric circuits

United States

K

Thermo-

wire KX

+

-

+

-

Thermocouples

+

-

Green

Green

Yel

Green

Blue

Brown

Red

Equalising- wire KCB

+

-

+

-

Green

Green

Green

Blue

T

Thermo-

wire TX

+

-

+

-

+

-

Brown

Brown

Blue

Brown

Blue

Brown

Red

J

Thermo-

wire JX

+

-

+

-

+

-

Black

Black

White

Black

Blue

Brown

Red

N

Thermo-

wire NX

+

-

+

-

Pink

Pink

Blue

Pink

Equalising- wire NC

+

-

+

-

Pink

Pink

Blue

Pink

E

Thermo-

wire EX

+

-

+

-

+

-

Purple

Purple

Purple

Brown

Blue

Purple

Red


Resistance thermometers

Resistance Thermometers

Color Codes

Connection Methods

2-Conductor Method

3-Conductor Method

Resistance Sensors


Color codes of resistance thermometers

Red

Red

Red

Blue

Blue

Red

Red

Red

RT

RT

RT

RT

White

White

White

White

White

Color Codes of Resistance Thermometers

In general, four different connection methods for resistance thermometers are possible:

4-conductor circuit with blind loop

2-conductor circuit

3-conductor circuit

4-conductor circuit

Resistance Sensors

In accordance with DIN 60751 (1996) and IEC751 (1983)


Overview of the connection methods for resistance sensors

Overview of the Connection Methods for Resistance Sensors

2-conductor measuring

3-conductor measuring

4-conductor measuring

RL

RL

RL

I

I

I

RL

RL

Resistance Sensors

PT 100

U

PT 100

U

PT 100

U

RL

I

I

I

RL

RL

RL

  • Conductor resistance and sensor resistance are added together

  • Systematic fault

    (dependent of:conductor length, conductor cross section and conductive material)

  • State of the art solution

  • Conductor resistance is not included in the measurement

  • Precondition:

    All conductors have the same resistance

  • Decreasing use

  • Conductor resistance is not included in the measurement

  • Conductors may have a differing resistance


Two conductor method for resistance sensors

R1

R2

RL

Uv

UB

IR

IT

RL

RT

I

R3

Two-Conductor Method for Resistance Sensors

Example: Classical Wheatstone-bridge with the two voltage dividers R1 and RT as well as R2 and R3 .

Precondition:

The conductor resistance values RL are negligible.

Resistance Sensors

For R1 / RT = R2 / R3 it is assumed that: UB = 0

The bridge is assumed to be balanced when : UB = 0.If the resistance RTchanges, the measuring voltage UBchanges proportionally.

Advantage of the Wheatstone-bridge: The value of the supply voltage is not included in the measurement.


Three conductor method for resistance sensors

R1

R2

IT

Uv

RL

UB

RT

IR

RL

R3

I

RL

Three-Conductor Method for Resistance Sensors

Example: Classical Wheatstone-bridge with three-conductor circuit and the two voltage dividers R1 and RT as well as R2 and R3, each of which also comprises the conductor resistance RL.

Precondition:

All conductor resistance RL values are equally high.

Resistance Sensors

For R1= R2and the balanced bridge it is assumed that: UB= 0 andIT= IR

  • Advantages:

  • The value of the supply voltage is not included in the measurement.

  • The conductor resistance has no influence on UB as each of the two voltage dividers comprise a conductor resistance RL.


Selection criteria for thermocouples and resistance thermometers

Selection Criteria for Thermocouples and Resistance Thermometers

Properties in Comparison

Types of Construction

Application Areas

Characteristic Curves

Selection Criteria


Properties of thermoelectric cells and resistance thermometers

Properties of Thermoelectric Cells and Resistance Thermometers

Thermocouples

Resistance Sensors

Accuracy

Good

Very good

Application Areas

Large temperature range

Small temperature range

Price

Cost-favorable

More expensive

Measuring Point

Small, point-shaped

Covering the length of the measuring resistance

Selection Criteria

Response Times

Very short

Relatively long

Reference Junction

Required

Not required

Surface Measurement

Very good suitability

Limited suitability

Vibration Resistance

Very robust

Limited suitability

Supply of Measuring Current

Not required

Required

Spontaneous Heating

Does not occur

Insignificant fault occurrence

Long-Term Stability

Satisfactory

Excellent

Robustness

Very good

Good

Connection Lines

Special materials

Standard cables


Selection of some types of construction of temperature sensors

Selection of Some Types of Construction of Temperature Sensors

Resistance

thermometer

Thermocouples

Angular thermocouples

Selection Criteria

Sheathed thermocouples

(bendable)

Sheathed resistance

thermometer

Wire-coiled

PT100

Foil thermocouples

Embedded resistance thermometer


Application areas of thermocouples and resistance thermometers

Metal welding, salt baths

Cooling and ventilation technology

Enamel and

ceramic tempering furnaces

Exhaust temperatures

Ambient temperatures

Boiler plants

Solid bodies

(e.g. film sealing jaws)

Combustion chamber monitoring

Application Areas of Thermocouples and Resistance Thermometers

Resistance thermometers

X

X

X

X

X

Selection Criteria

Sheathed resistance thermometers (bendable)

X

X

X

X

Thermo-

couples

X

X

X

X

Sheathed thermo-couples(bendable)

X

X

X

X

X

Angular thermo-couples

X

Temperature


Characteristic curves of some thermocouples and resistance thermometers

U [mV]

R []

NTC

80

4000

Type E

60

3000

PT1000

Type J

40

2000

Type K

20

1000

PT100

0

250

500

750

T [°C]

Characteristic Curves of Some Thermocouples and Resistance Thermometers

Conversion of °C to °F: °C = (°F-32)/1.8 °F = 1.8°C+32

Selection Criteria


Controlling

Controlling

The Control Circuit

2-Position Controllers

3-Position Controllers

PID Controllers with Clocking Output

PID Controllers with Analogue Output

Controllers with Integrated Automatic Adjustment

Controlling


The control circuit

Disturbance variables

Z

Control point

Final controlling element

(heating)

Control path

(system)

Measuring junction

Measuring device

(sensor)

Control Circuit

Setpoint value adjuster

reference input element

(SPC)

Intensifier

(SC-contactor)

Referencejunction

Setpoint value

The Control Circuit

The control circuit serves the adjustment of a pre-specified measurement to the desired value and the limitation of such realised value within a reasonable tolerance range.

Controlling

Controlling means:

A constant comparison between the measured and required value and, in cases of deviations, the necessary correction of such deviation with the help of the final controlling element.


Two position controller with hysteresis shown in a heating application

TMax

TSetpoint e.g. 80°C

Hysteresis range

Hysteresis

value

TMax= Maximum attainable temperature;

limited by the heating power

TSetpoint = Switch-off temperature

t Start= Preheating time

t 0= Controlling clocking time

t

t Start

t 0

Two-Position Controller with Hysteresis, Shown in a “Heating” Application

When the TSetpoint temperature is attained, the two-position controller switches off the heating. As soon as the temperature has attained the hysteresis value, the heating is switched back on again.

Controlling

  • Examples:

  • Heating chambers for stress tests of electronic modules

  • Water heating within instantaneous water heaters, pipe heat tracings for frost protection, ...

  • Can analogously also be used for cooling applications, e.g. with cooling and air-conditioning systems, switchgear cabinets, water-cooled operating mechanisms and lasers, ...


Example of a 2 position controller with hysteresis frost protection with pipe heat tracings

L1

S1

11

12

A1

A3

11

13

K1

K1

T1

J

H1

L2

T2

14

12

T3

A2

NSB01333b

Example of a 2-Position Controller with Hysteresis: Frost Protection with Pipe Heat Tracings

The two-position controller switches on the pipe heat tracing at 5°C. As soon as the temperature has reached the hysteresis value of 7°C, the pipe heat tracing is switched back off again.

Switch-on value

Controlling

Hysteresis value

(Illustration with appliedsupply voltage, temperature

lies above the threshold value)

  • Advantages of Simirel 3RS1010-1CD00:

  • Cost-favorable solution

  • Simple construction, easy setting

  • Can also be used for cooling applications, e.g. with cooling and air-conditioning systems, switchgear cabinets, water-cooled operating mechanisms and lasers, ...


3 position controller with two filament windings and hysteresis shown in a heating application

  • Advantage:

  • Short preheating time and long

    clocking time with few switching cycles and little current variations

Example:

  • Heat treatment ovens for metal processing

  • Decompression furnaces

3-Position Controller with Two Filament Windings and Hysteresis, Shown in a “Heating” Application

The three-position controller switches the first heating off when the temperature T1 is attained and the second heating when the temperature TSetpoint is attained.

(TSetpoint approx. 50 % of TMax (two heatings) and approx. 90 % of TMax (one heating).)

TMax = Maximum attainable temperature;

limited by the heating power

TSetpoint = Switch-off temperature of the second heating

T1 = Switch-off temperature of the first heating

t Start= Preheating time

t 0= Controlling clocking time

TMax

TSetpoint e.g. 130°C

Controlling

Hysteresis range

Hysteresis range

T1 e.g. 110°C

t

t Start

t 0


Example of a 3 position controller with hysteresis temperature controlling in heat treatment ovens

L1

S1

15

25

33

18

34

26

28

16

H11

K15

K25

H15

H25

H33

L2

Example of a 3-Position Controller with Hysteresis:Temperature Controlling in Heat Treatment Ovens

  • Mode of Operation:

  • Required task:

Temperature control of two filament windings within a heat treatment oven with the help of a three-position controller.

  • Wiring diagram of 3RS1040:

  • Solution with SIMIREL 3RS1040/3RS1140 :

  • In contrast to the classical two-position controller with only one filament winding, this principle both works with a heating power whose power only generates slow temperature changes in a stationary process state as well as with a second, stronger filament winding which is able to generate fast heating processes. After the preheating phase, i.e. after the process temperature has been attained, the second filament winding may be switched off.

  • The controller will only switch the second heating back on again if the first off-switching temperature is undershot, e.g. when opening the oven door. During normal operation, merely the poorer performing heating is switched on in accordance with the heating requirements.

Controlling

  • Advantages and special characteristics:

  • -The preheating phase is significantly shortened.

  • -Current and temperature fluctuations are kept insignificant during the entire course of operation.

  • -The switching frequency is reduced as the heating power can be adjusted to the process requirements relatively accurately.


Pid controller with on off control

T

T Setpoint

T Actual

t

Relay “On”

Relay “Off”

PID Controller with On-Off Control

The PID controller with On-Off Control changes its On-Off ratio depending on the difference between the setpoint value and the actual value.

Controlling

Intervals are thus continuously becoming longer while heating times become shorter.


Pid controller with analog output

PID Controller with Analog Output

The PID controller with analog output changes its correcting variable depending of the difference between the setpoint value and the actual value.

T Setpoint

T

T Actual

Controlling

t

Umax

Correcting variable

Umin

t

Correcting values are thus continuously becoming smaller. Umin keeps the temperature at TSetpoint .


Temperature controllers with auto tuning

Manual

setting

Automatic

adjustment

ON/OFF

The PID constantsare determined

Controller reaction

after calculation of PID constants

Manual

setting

Temperature Controllers with Auto Tuning

  • Many controllers are equipped with a system with which they can determine the required PID parameters independently. To do this, they switch the heating completely on and measure the proportional factor, dwell time and lead time (self-learning).

Setpoint value

Alarm setpoint value

Proportional band

Dwell time

Controlling

Lead time

Compensation variable

  • In addition, there are controller types which also continuously optimise these parameters (self-optimising).

Input value deferral


Controlling monitoring

Controlling & Monitoring

Why is

Control Monitoring Necessary?

Monitoring with 3RS17

Monitoring with

3RS10/3RS11

Controlling & Monitoring


Why is temperature monitoring necessary despite controller devices

Why is Temperature Monitoring Necessary Despite Controller Devices?

The control circuit is made up of a chain of various hardware and software components.

Disturbance variables

Z

Control point

Final controlling element

(heating)

Control path

(system)

Measuring junction

Measuring device

(sensor)

Control Circuit

Setpoint value adjuster

reference input element

(SPC)

Controlling & Monitoring

Interruption,

e.g. breakage

Intensifier

(SC-contactor)

Reference junction

Setpoint value

In cases of component or connection line failures, in cases of software faults as well as in cases of too large disturbance variables, the controller can no longer guarantee a compliance with the temperature limits.


Controller devices with additional temperature monitoring and second sensor

Controller Devices with Additional Temperature Monitoring and Second Sensor

Disturbance variables

Z

Control point

Final controlling element

(heating)

Control path

(system)

Measuring junction

Measuring devices

(2 sensors)

Control Circuit

Setpoint value adjuster

reference input element

(SPC)

Intensifier

(SC-contactor)

Reference junction

Controlling & Monitoring

Temperature monitoring relay

(3RS10/3RS11)

Warning light

  • Advantages:

  • The second sensor offers additional protection.

  • The monitoring of second sensor operates in parallel with the control circuit. Thus, the existing control system need not be altered.


Controller devices with 3rs17 temperature converter and one sensor planned

Controller Devices with 3RS17 Temperature Converter and One Sensor (Planned)

Disturbance variables

Z

Control point

Final controlling element

(heating)

Control path

(system)

Measuring junction

Measuring device

(1 sensor)

Control Circuit

Setpoint value adjuster

reference input element

(SPC)

Intesifier

(SC-contactor)

Referencejunction

Controlling & Monitoring

0/4-20mA, 0-10V

Temperature

monitoring relay

(3RS17)

Warning light

  • Advantages:

  • SPC connection and temperature limiter within one device

  • Warning signal when the first temperature limit is reached

  • Disruption of the control system‘s energy supply when theset maximum temperature is exceeded


3rs10 3rs11 device overview

3RS10/3RS11 Device Overview

Overview Split by Sensors

Overview Split by Scopes

of Functionality

Product Details

Analog devices with 1 threshold value

Analog devices with 2 threshold values

Digital devices with 2 threshold values

Setting Parameters

Function Diagrams

Establishment of an Average Temperature

Product Overview


Product overview split by sensors

Product Overview Split by Sensors

  • For Thermocouples

  • Voltage potential

  • proportional to the temperature

- Type J -99°C up to + 999°C

- Type K -99°C up to +999°C

- Type N -99°C up to + 999°C

- Type T -99°C up to + 400°C

- Type E -99°C up to + 999°C

  • For Resistance Sensors

  • Resistance value

  • proportional to the temperature

Product Overview

- PT100-50°C up to + 500°C

- PT1000-50°C up to + 500°C

- KTY 83-50°C up to + 175°C

- KTY 84-40°C up to + 300°C

- NTC+80°C up to + 160°C


Product overview split by functionality

Product Overview Split by Functionality

Analog Devices with One Setpoint Value

Analog Devices with Two Setpoint Values

Digital Devices

Closed current principle

Working/closed current

principle

2- or 3-position controller

Product Overview

Setting of limit values and hysteresis via a rotary potentiometer

Very easy parameterisation with rotary switch and two pushbuttons


Product details analog devices with one threshold value

L1

A1

11

13

3RS1000/1010

1100/1101

1110/1111

T1/+

A2

12

14

T2/-

Trip

Signal

-K1

-H2

TC / RS

Product Details: Analog Devices with One Threshold Value

Product Overview

One threshold value with adjustable hysteresis

  • The top-seller

  • PT100, Type J, Type K

  • Closed current principle

  • Overflow or underflow

  • Different temperature ranges


Product details analog devices with two setpoint values

L1

11

A1

23

3RS1020/1030

1120/1121

1130/1131

T1/+

A2

24

12

14

T2/-

Signal

-H2

Alarm

Trip

-H3

-K1

TC / RS

Product Details: Analog Devices with Two Setpoint Values

Product Overview

Two threshold values and adjustable hysteresis

  • Warning and off-switching

  • PT100, Type J, Type K

  • Working or closed current principle

  • Overflow or underflow

  • Different temperature ranges


Product details digital devices with two setpoint values

L1

A1

15

25

33

3RS1040/1041

1140

34

16

18

26

28

T1/+

A2

T2/-

Trip

-K1

-K2

Display

-H1

TC / RS

-H3

-H2

Wire breakage/Short circuit

Product Details: Digital Devices with Two Setpoint Values

Product Overview

Two threshold values and ajdustable hysteresis

  • The expert

  • For all common sensors

  • LED display

  • Overflow, underflow,

    window monitoring

  • Adjustable hysteresis and delay time

  • 1CO + 1CO + 1NO


Digital devices parameterisation example 3rs1040

Down

Up

Parameter selection

Digital Devices:Parameterisation Example: 3RS1040

Rotary selector switch for parameter selection

Pushbutton for

“Up” or “Down”

1. Threshold value J1

2. Threshold value J2

3. Hysteresis

4. Delay time

5. Working principle

WORKING

CLOSED

Product Overview

6. Mode of operation

UNDERFLOW

OVERFLOW

WINDOW

7. Sensor type

PT1000

PT100

KTY83

KTY84

NTC

8. Operation (RUN)

ACTUAL TEMPERATURE


Function diagram temperature overshoot

Function Diagram:Temperature Overshoot

Mode of operation:

working current principle

Mode of operation:

closed current principle

J1 < J2

J1 < J2

J2

J2

J1

J1

Us

Us

Product Overview

K1

K1

Delay

Delay

K2

K2

Delay

Delay


Function diagram temperature undershoot

Function Diagram: Temperature Undershoot

Mode of operation:

working current principle

Mode of operation:

closed current principle

J1 > J2

J1 > J2

J1

J1

J2

J2

Us

Us

Product Overview

K1

K1

Delay

Delay

K2

K2

Delay

Delay


Function diagram window monitoring

Delay

Delay

Function Diagram:Window Monitoring

Mode of operation:

working current principle

Mode of operation:

closed current principle

J1 < J2

J1 < J2

J2

J2

J1 > J2

J1

J1

Us

Us

Product Overview

K1

K1

Delay

K2

K2

Delay


Establishing the average temperature within a medium with the help of several sensors

Establishing the Average Temperature Within a Medium with the Help of Several Sensors

In many cases, the average temperature within a medium or that on a specific surface is of special interest. Such measurement can easily be realised with the use of the wiring diagram illustrated below as well as a 3RS11 temperature monitoring relay.

T1

Measuring point 1

T2

Measuring point 2

T3

Measuring point 3

  • Mode of operation:

  • As soon as different temperatures are detected between the thermoelectric cells, equalising currents will flow within the conductors. They serve to ensure that the average value of the single voltages is realised at the connection junction, given that all conductors have the same conductive resistance.

Tips & Tricks


92 definitions would you have known them

92 Definitions: Would You Have Known Them?

Almost everything you needto know about temperaturemonitoring relevant definitions

From A - Z

92 Definitions


Definition of terms abs com

Alumel

Trading name of the high-temperature resistant nickel alloy NiAl which, together with chromel, forms the Type K thermocouple.

Adjustment time

Compensation device

Ceramic insulation

Black body

Calorie [cal]

Blind loop

Absolute zero

Chromel

Ensures that the measured value is largely independent of influential variables (disturbance variables).

Quantity of energy required to heat 1 gram of water from 14°C to 15°C.

A body which absorbs all occurring radiation and emits the maximum thermal radiation.

Trading name of the high-temperature resistant nickel alloy NiAl which, together with alumel, forms the Type K thermoelectric couple.

Additional conductor loop from the measuring device to the sensor used to compensate conductor resistance and parasitic voltages.

The lowest temperature a substance can have. It is also the starting point of the Kelvin scale (-273.15°C).

Time period between a sudden change of the input size and the adjustment of the output size to its balancing setpoint value.

High-temperature resistant ceramics (sintered aluminium oxide, corundum, silmanite or magnesium oxide). It is used as a material for protective pipes or for small insulating rods of thermometers.

Definition of Terms Abs - Com

92 Definitions


Definition of terms con ext

Depth of immersion

EMF

Equalising conductors

Emissivity coefficient

External reference junction temperature

Drift

Earthedmeasuring junction

Exposed measuring junction

Constantan

The length of the thermometer component which is exposed to the measuring value.

Electromotive Force which, e.g., effects a voltage difference by ways of thermoelectric energy within a conductor.

Ratio of the optical radiated power of a substance compared with a black body of the same temperature.

Reference junction temperature which is used for the determination or establishment of the signal voltage when thermocouples are applied.

Conductors for a cost-favourable length expansion of measuring conductors for thermocouples (limited measuring ranges).

Copper-Nickel alloy which was developed as a material for electric resistance. Yet, it is also used as a negative arm for the Type K and Type T thermoelectric couples.

Shift of a measuring signal over a long period of time.

Thermocouples whose measuring junction is welded with the protective cover (same potential as the system).

The measuring junction of a thermocouples is in direct contact with the medium to be measured without any mechanical protection (to facilitate a fast response behaviour).

Connecting head

Cover or casing for sealing protective pipes used with thermocouples or resistance thermometers.

Definition of Terms Con - Ext

92 Definitions


Definition of terms fah kel

Hot junction

Internal conductors

Intrinsically safe electric circuits

Insulated measuring junction

Isothermal

Indicial response

IST- 90

Kelvin scale

Joule

Fahrenheit

Designation for the measuring junction of a thermocouple.

Electrical connection between the actual measuring resistance and the external connections of the sensor element.

The hot junction of thermocouples which is electrically insulated against the protective cover or the tubular jacket.

State of a homogeneous and constant temperature.

Unit of measurement for energy.

International temperature scale of 1990.

Anglo-Saxon temperature scale (32°F = 0°C / 212°F = 100°C).

Representation of the temporal course of a measured value or the output signal after a sudden change of the measured variable.

The switching circuit is arranged in such a way that sufficient electric energy for the igniting of flammable substances can under no circumstances whatsoever be transferred or saved.

Temperature scale for the measured variable of the thermodynamic temperature. The scale definition starts with absolute zero (-273.15°C).

Definition of Terms Fah - Kel

92 Definitions


Definition of terms lif mea

Measured value

Life zero

Linearity

Measuring junction

Limit conditions

Measuring fault

Loop resistance

Measuring point

Measured variable

Measured value hysteresis value

Hysteresis: Differential sum of the measured values for the same value of the measured variable when this value is reached in increasing or decreasing direction.

This minimum current of 4mA is normally used for power supply and conductor monitoring; values of under 4mA are a proof for occurred faults.

Directly proportional ratio of an instrument‘s display value and the measured value.

Maximum ambient conditions a thermometer can be exposed to without consequential damage or deterioration.

Total resistance of the measuring loop, including the measuring element, contact resistance and conductor resistance.

Connection points of the welded, soldered or twisted thermoelectric arms of a thermocouple.

Point within a medium or a substance at which the measurement is carried out.

A feature whose value is to be determined with the help of a measurement (e.g. temperature).

Undesired deviation between the actual value of a measuring device and its setpoint value.

Value of a measuring unit determined by way of a measurement. It is made up of the product of numeric value and unit.

Definition of Terms Lif - Mea

92 Definitions


Definition of terms mea ove

Negative temperature coefficient (NTC)

Measuring range

Measuring resistor

NTC resistors

Medium temperature coefficient a

Müller bridge

Nominal resistance

Overtravel deviation

Noise

Nicrosil-Nisil

Type N thermoelectric couple which is made of a Nickel-Chrome alloy and a Nickel-Silicium alloy.

Maximum value range of a measuring device.

Sensor element of a resistance thermometer whose electric resistance depends on the temperature.

Medium relative resistance change per Kelvin within the range of 0°C and 100°C.

Highly precise measuring bridge configuration for resistance thermometers with 3-conductor circuits.

Sensors with a negative temperature coefficient. With an increase in temperature, the electric resistance decreases (NTC).

Measuring deviation due to a temporal overtravel of the measured value or the output signal compared with a sudden change of the measured variable.

Undesired effect caused by electromagnetic radiation of the signal conductors.

Setpoint value of the temperature-dependent resistance at 0°C.

Ratio of the temperature difference and the resistance difference of NTC resistors. With an increase in temperature, the resistance decreases.

Definition of Terms Mea - Ove

92 Definitions


Definition of terms pel ref

Peltier effect

Polarity

Reference junction

Positive temperature coefficient (PTC)

Pyrometry

PT100

Reference junction thermostat

PTC resistor

Sensors with a positive temperature coefficient. With an increase in temperature, the electric resistance also increases (PTC).

Reversion of the Seebeck effect. With a current-imposed conductor consisting of two metals, one connection junction is supplied with heat while the other one is subjected to heat dissipation.

Designation of the plus and minus arms of thermocouples.

Ratio of the temperature difference and the resistance difference of PTC resistors. With an increase in temperature, the resistance increases.

Connection junction of the thermocouples lying on the reference temperature.

Temperature measurement with the help of radiation pyrometers. The thermal radiation of a body is used for temperature measurement.

Platinum resistor element with a nominal resistance of 100 Ohm at 0°C.

Externally tempered measuring circuit with a constant and known temperature which is taken as a reference for reference junction compensation.

Reference junction compensation

Adjustment of the output signal of a thermocouple if the reference junction is not specified at 0°C.

Definition of Terms Pel - Ref

92 Definitions


Definition of terms ref see

Resistance temperature sensor

Reference value

Seebeck coefficient

Repeatability

Resistance element

Response time

Seebeck effect

Resistancethermometer

Consisting of a measuring resistor within a protective cover, the internal conductors and the external connections.

Value which is based on the incorporation of measurement results, the determination of fault limits or other conditions.

The capability of a sensor or a measuring system to reproduce the same measuring signal under identical conditions.

Is used within resistance thermometers for measuring the temperature.

Initial derivation of the thermal EMF with regard to the temperature, stated in [V/°C].

An instrument or measuring system consisting of one measuring device and one resistance temperature sensor which has a known ratio of resistance and temperature. The temperature is determined on the basis of the resistance measurement.

Time period between a temperature change of the medium to be measured and the sensor output signal.

Generation of an electromotive force (EMF) by way of the temperature difference between the two connection junctions of two different metals which are part of an electric circuit.

Definition of Terms Ref - See

92 Definitions


Definition of terms see the

Stabilisation

Sensitivity

Thermal expansion

Sensor element

Sheathed thermoelectric cells

Thermal conductivity

Temperature sensor

Thermal radiation

Temperature gradient

Artificial weathering of measuring sensors based on heat treatment.

The response behaviour of a temperature sensor as regards the time period or signal size of a given temperature difference.

Designation of a serviceable sensor which is integrated in a protective fitting.

Thermocouples with mineral-insulated sheathed conductor. The thermoelectric arms are embedded in pressed magnesium oxide within a tubular jacket made of stainless steel.

Measurement for the heat quantity per temporal unit which flows between bodies of differing temperatures during heat transmission.

Temperature variation within a substance.

The part of the thermometer which is directly exposed to the temperature.

Expansion of a body with an increase in temperature.

Electromagnetic radiation which is emitted by a body with a temperature of above absolute zero.

Spontaneous heating

Influential effect which is generated by the electric power transferred by the measuring current within the measuring resistance.

Definition of Terms See - The

92 Definitions


Definition of terms the tra

Thermistor

Transducer

Thermoconductor

Thermoelectric arm

Thomson effect

Thermoelectric cells

Transition point

Thermoelectric couples

Thermometer resistance

Two interconnected electric conductors made of different materials which supply a thermal voltage or a thermal current on the basis of the Seebeck effect.

Semiconductor-sensor with a non-linear ratio of resistance change and temperature change (PTC).

Conductor couple for the expansion of the thermoelectric arm to the reference junction consisting of the same material as the thermoelectric arm.

Single conductor of a thermocouple. Depending on the polarity, “plus” and “minus” thermoelectric arms are differentiated.

Temperature sensors which supply a direct electric voltage or electric current by utilising their thermoelectric properties.

The sum of the entire resistance within a resistance thermometer (internal conductors and measuring resistance).

Effects a change of the heat concentration within a current-imposed conductor within a temperature gradient.

Transformer which transforms a physical measurement, e.g. temperature, into a current or voltage signal.

Sealing which covers the connection junction of the thermoelectric arms with the thermowires or equalisinwires.

Definition of Terms The - Tra

92 Definitions


Definition of terms tra zer

Wheatstone bridge

Two-, three- or four-conductor circuits

Transmitter

Triple point

Zero suppression

Zero shift

A measuring bridge consisting of four resistors and serving the precise determination of resistance within a measuring circuit.

Type of connection of a resistance temperature sensor to a display device with two-, three- or four-conductor incoming supply.

Transformer which transforms any voltage or current signals into standardised voltage or current signals.

Temperature at which a substance can exist stable in all three phase conditions. The triple point of water lies at 0.01°C.

Measuring range shift to receive a higher accuracy in a measuring device‘s relative measuring range.

Difference between the displayed zero value and the actual zero.

Definition of Terms Tra - Zer

92 Definitions


Simirel relays for all applications

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