Industrial Platinum Resistance Thermometers and Platinum Temperature Sensors
1 Scope
This standard specifies the requirements and temperature/resistance relationship for industrial platinum resistance temperature sensors (later referred to as “platinum resistors” or "resistors") and industrial platinum resistance thermometers (later referred to as "thermometers"), whose electrical resistance is a defined function of temperature.
This standard applies to platinum resistors whose temperature coefficient α, defined as is conventionally written as α = 3.851×10-3°C-1,
(1)
where: R100 is the resistance at t = 100°C and R0 is the resistance at t = 0°C.
Values of temperature in this standard are in terms of the International Temperature Scale of 1990 (ITS-90). Temperatures in degrees Celsius (°C) are denoted by the symbol t, except in Table 1 where the full nomenclature t90/°C is used.
This standard covers resistors or thermometers for all or part of the temperature range -200°C to +850°C with different tolerance classes, which may cover restricted temperature ranges.
For temperature/resistance relationships with uncertainties <0.1°C, which are possible only for resistors or thermometers with exceptionally high stability and individual calibration, a more complex interpolation equation than is presented in this standard may be necessary. The specification of such equations is outside the scope of this standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 61152 Dimension of Metal-sheathed Thermometer Elements
IEC 61298-1 Process Measurement and Control Devices — General Methods and Procedures for Evaluating Performance — Part 1: General Considerations
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
dielectric strength
maximum voltage between all parts of the electric circuit and the sheath of the thermometer or, in the case of a thermometer with two or more sensing circuits, between two individual circuits which the thermometer can withstand without damage. The measurement conditions for d.c and a.c (with frequency) have to be specified
3.2
insulation resistance
electrical resistance measured between any part of the electric circuit and the sheath at ambient or elevated temperatures and with a specified measuring voltage (a.c or d.c)
3.3
minimum immersion depth
immersion depth at which the change from the calibration at full immersion does not exceed 0.1°C
3.4
nominal resistance
expected resistance R0 of a resistor or resistance thermometer at 0°C, declared by the manufacturer and shown in the thermometer marking, usually rounded to the nearest ohm. Platinum resistors are often characterized by their nominal: A Pt-100 resistor is a resistor with R0=100 Ω
3.5
platinum resistance thermometer (PRT)
temperature responsive device consisting of one or more sensing platinum resistors within a protective sheath, internal connecting wires and external terminals to permit connection of electrical measurement instruments. Mounting means and connection heads may be included. Not included is any separable protection tube or thermowell
3.6
temperature sensitive length
length of the thermometer whose temperature directly influences the resistance measured. Usually the temperature sensitive length is related to the length of the resistor
3.7
platinum resistor
resistor made from a platinum wire or film with defined electrical characteristics, embedded in an insulator (in most cases glass or ceramic), designed to be assembled into a resistance thermometer or into an integrated circuit
3.8
self-heating
increase of the temperature of the resistor or of the resistor in a thermometer caused by the dissipated energy of the measuring current
3.9
self-heating coefficient
coefficient with the dimension°C/mW is characteristic for a resistor/thermometer and describes the temperature increase of the resistor per unit power dissipated. This coefficient is evaluated under specified operating conditions of the resistor or thermometer. The medium, its flow conditions and temperature should be specified
3.10
terminals
termination of the connections supplied with the resistance thermometer
Note: Typical types of terminals are:
— screws or clamps on the terminal socket;
— pins of fixed connectors;
— open ends of fixed cables, or equivalents.
3.11
thermal response time
time a thermometer takes to respond at a specified percentage to a step change in temperature. To specify the response time, it is necessary to declare the percentage of response, usually τ0.9, τ0.5, or τ0.1, which gives the time for 90%, 50% or 10% of the response. The test medium and its flow conditions have to be specified (usually flowing water and/or flowing air)
3.12
thermoelectric effect
effect of inducing the electro-motive force (EMF) caused by different metals used in the electric circuit of the thermometer and by thermoelectric inhomogeneity of the internal leads at the conditions of temperature gradients along the leads. The induced EMF is measured across the terminals of the thermometer while the thermometer is subjected to a specified temperature
Foreword II
1 Scope
2 Normative references
3 Terms and Definitions
4 Characteristics
4.1 Temperature/Resistance Relationships
4.2 Resistance Values
5 General Requirement
5.1 Tolerance Classes
5.2 Measuring Current
5.3 Electrical Supply
5.4 Connecting Wire Configuration
6 Test
6.1 General
6.2 Routine Production Tests for Resistors
6.3 Routine Production Tests for Thermometers
6.4 Type Tests for Resistors
6.5 Type Tests for Thermometers
6.6 Additional Type Tests for Special Applications of Thermometers
6.7 Summary of Tests
7 Information to be Made Available by the Manufacturer
7.1 For Resistors Only
7.2 For Resistors and/or Thermometers
8 Thermometer Identification and Marking
Annex NA (Informative) Description of Test Methods for Fabricated Platinum Resistance Thermometers
Annex NB (Informative) Methods to Assure Resistors of the Appropriate Tolerance Class
Industrial Platinum Resistance Thermometers and Platinum Temperature Sensors
1 Scope
This standard specifies the requirements and temperature/resistance relationship for industrial platinum resistance temperature sensors (later referred to as “platinum resistors” or "resistors") and industrial platinum resistance thermometers (later referred to as "thermometers"), whose electrical resistance is a defined function of temperature.
This standard applies to platinum resistors whose temperature coefficient α, defined as is conventionally written as α = 3.851×10-3°C-1,
(1)
where: R100 is the resistance at t = 100°C and R0 is the resistance at t = 0°C.
Values of temperature in this standard are in terms of the International Temperature Scale of 1990 (ITS-90). Temperatures in degrees Celsius (°C) are denoted by the symbol t, except in Table 1 where the full nomenclature t90/°C is used.
This standard covers resistors or thermometers for all or part of the temperature range -200°C to +850°C with different tolerance classes, which may cover restricted temperature ranges.
For temperature/resistance relationships with uncertainties <0.1°C, which are possible only for resistors or thermometers with exceptionally high stability and individual calibration, a more complex interpolation equation than is presented in this standard may be necessary. The specification of such equations is outside the scope of this standard.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
IEC 61152 Dimension of Metal-sheathed Thermometer Elements
IEC 61298-1 Process Measurement and Control Devices — General Methods and Procedures for Evaluating Performance — Part 1: General Considerations
3 Terms and Definitions
For the purposes of this document, the following terms and definitions apply.
3.1
dielectric strength
maximum voltage between all parts of the electric circuit and the sheath of the thermometer or, in the case of a thermometer with two or more sensing circuits, between two individual circuits which the thermometer can withstand without damage. The measurement conditions for d.c and a.c (with frequency) have to be specified
3.2
insulation resistance
electrical resistance measured between any part of the electric circuit and the sheath at ambient or elevated temperatures and with a specified measuring voltage (a.c or d.c)
3.3
minimum immersion depth
immersion depth at which the change from the calibration at full immersion does not exceed 0.1°C
3.4
nominal resistance
expected resistance R0 of a resistor or resistance thermometer at 0°C, declared by the manufacturer and shown in the thermometer marking, usually rounded to the nearest ohm. Platinum resistors are often characterized by their nominal: A Pt-100 resistor is a resistor with R0=100 Ω
3.5
platinum resistance thermometer (PRT)
temperature responsive device consisting of one or more sensing platinum resistors within a protective sheath, internal connecting wires and external terminals to permit connection of electrical measurement instruments. Mounting means and connection heads may be included. Not included is any separable protection tube or thermowell
3.6
temperature sensitive length
length of the thermometer whose temperature directly influences the resistance measured. Usually the temperature sensitive length is related to the length of the resistor
3.7
platinum resistor
resistor made from a platinum wire or film with defined electrical characteristics, embedded in an insulator (in most cases glass or ceramic), designed to be assembled into a resistance thermometer or into an integrated circuit
3.8
self-heating
increase of the temperature of the resistor or of the resistor in a thermometer caused by the dissipated energy of the measuring current
3.9
self-heating coefficient
coefficient with the dimension°C/mW is characteristic for a resistor/thermometer and describes the temperature increase of the resistor per unit power dissipated. This coefficient is evaluated under specified operating conditions of the resistor or thermometer. The medium, its flow conditions and temperature should be specified
3.10
terminals
termination of the connections supplied with the resistance thermometer
Note: Typical types of terminals are:
— screws or clamps on the terminal socket;
— pins of fixed connectors;
— open ends of fixed cables, or equivalents.
3.11
thermal response time
time a thermometer takes to respond at a specified percentage to a step change in temperature. To specify the response time, it is necessary to declare the percentage of response, usually τ0.9, τ0.5, or τ0.1, which gives the time for 90%, 50% or 10% of the response. The test medium and its flow conditions have to be specified (usually flowing water and/or flowing air)
3.12
thermoelectric effect
effect of inducing the electro-motive force (EMF) caused by different metals used in the electric circuit of the thermometer and by thermoelectric inhomogeneity of the internal leads at the conditions of temperature gradients along the leads. The induced EMF is measured across the terminals of the thermometer while the thermometer is subjected to a specified temperature
Contents of GB/T 30121-2013
Foreword II
1 Scope
2 Normative references
3 Terms and Definitions
4 Characteristics
4.1 Temperature/Resistance Relationships
4.2 Resistance Values
5 General Requirement
5.1 Tolerance Classes
5.2 Measuring Current
5.3 Electrical Supply
5.4 Connecting Wire Configuration
6 Test
6.1 General
6.2 Routine Production Tests for Resistors
6.3 Routine Production Tests for Thermometers
6.4 Type Tests for Resistors
6.5 Type Tests for Thermometers
6.6 Additional Type Tests for Special Applications of Thermometers
6.7 Summary of Tests
7 Information to be Made Available by the Manufacturer
7.1 For Resistors Only
7.2 For Resistors and/or Thermometers
8 Thermometer Identification and Marking
Annex NA (Informative) Description of Test Methods for Fabricated Platinum Resistance Thermometers
Annex NB (Informative) Methods to Assure Resistors of the Appropriate Tolerance Class
