QC/T 556-2023 Temperature measurement methods and thermocouple installation requirements for automotive brakes
1 Scope
This document specifies the terms and definitions, measuring equipment, thermocouple installation, installation of infrared thermometry, and measurement methods for temperature measurement of automotive brakes.
This document is applicable to temperature measurement during automotive brake tests.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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.
GB/T 5620 Road vehicles - Vocabulary and definition for braking of automotive vehicles and their trailers
GB/T 16839.1 Thermocouples - Part 1: EMF specifications and tolerances
GB/T 30429 Industrial thermocouple assemblies
JB/T 5582 Specification of industrial sheathed thermocouple assemblies
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 16839.1 and GB/T 5620 as well as the following apply.
3.1
contact thermometry
temperature measurement method in which the temperature-sensing element is in contact with the measured object and reaches thermal equilibrium
Note: Common contact thermometry methods include thermocouple thermometry and resistance thermometry.
3.2
non-contact thermometry
temperature measurement method in which the temperature-sensing element is not in contact with the measured object
Note: Common non-contact thermometry methods include radiation thermometry and spectral thermometry.
3.3
embedded thermocouple
thermocouple whose measuring junction is designed to be embedded inside the measured object
3.4
rubbing thermocouple
thermocouple whose measuring junction remains in contact with the surface of the measured object at all times
3.5
infrared thermometry
measuring instrument that measures temperature by using the radiant flux of a thermal radiator in the infrared band
Note: One type of measuring instrument used in non-contact thermometry.
4 Measuring equipment
4.1 Measuring equipment for contact thermometry
4.1.1 The contact temperature measuring equipment shall meet the following requirements:
a) The EMF specifications and tolerances of the thermocouple selected based on the temperature range and environmental conditions shall meet the requirements of GB/T 16839.1;
b) The embedded thermocouple shall meet the requirements of GB/T 30429; the requirements for the rubbing thermocouple may refer to JB/T 5582.
4.1.2 See Annex A for the structural configurations of commonly used thermocouples.
4.2 Measuring equipment for non-contact thermometry
The non-contact temperature measuring equipment (infrared thermometry) shall meet the following requirements:
a) It shall be capable of continuously recording the temperature of the measured object;
b) It shall be designed to prevent lenses from being contaminated by dust, smoke, and other pollutants.
c) It shall be capable of withstanding an ambient temperature of not less than 70°C.
4.3 Display and recording device
The device for displaying and recording the dynamic temperature of the brake shall meet the following requirements:
a) It shall be capable of self-calibration (automatic compensation);
b) The indication error shall be less than 3% of the measured value;
c) The dynamic response time shall not exceed 0.2 s.
5 Thermocouple installation
5.1 Embedded thermocouple
5.1.1 Installation on the brake lining assembly
5.1.1.1 For the brake shoe assembly, the measuring junction of the thermocouple shall be installed at a location adjacent to the point of maximum load on the brake lining of the leading shoe assembly. When ribs, heat-dissipating fins, grooves, or rivet holes are present at this location, the position shall be offset by more than 5 mm.
5.1.1.2 For a pad assembly, the measuring junction of the thermocouple shall be installed at the center of the brake lining in both the length and width directions. When the brake lining has a groove, the position shall be adjusted, along the center of the friction track on the working surface, to a location on the rotating-out side that is not less than 7.5 mm from the groove edge; when temperature measurement is required for the brake lining in contact with the piston and the above arrangement is impractical, the position shall be adjusted, along the center of the friction track on the working surface, to a location on the rotating-out side that is not less than 5 mm from the edge of the effective piston action diameter on the pad assembly.
5.1.1.3 A through hole (whose aperture shall be determined by the outer diameter of the measuring junction of the thermocouple) shall be processed at the corresponding installation position. The measuring junction of the thermocouple shall be fixed in the hole without any looseness, and positioned (1±0.2) mm from the friction surface, as shown in Figures 1 and 2.
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Measuring equipment
5 Thermocouple installation
6 Installation of infrared thermometry
7 Measurement methods
Annex A (Informative) Structural configurations of commonly used thermocouples
QC/T 556-2023 Temperature measurement methods and thermocouple installation requirements for automotive brakes
1 Scope
This document specifies the terms and definitions, measuring equipment, thermocouple installation, installation of infrared thermometry, and measurement methods for temperature measurement of automotive brakes.
This document is applicable to temperature measurement during automotive brake tests.
2 Normative references
The following documents contain provisions which, through reference in this text, constitute provisions 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.
GB/T 5620 Road vehicles - Vocabulary and definition for braking of automotive vehicles and their trailers
GB/T 16839.1 Thermocouples - Part 1: EMF specifications and tolerances
GB/T 30429 Industrial thermocouple assemblies
JB/T 5582 Specification of industrial sheathed thermocouple assemblies
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 16839.1 and GB/T 5620 as well as the following apply.
3.1
contact thermometry
temperature measurement method in which the temperature-sensing element is in contact with the measured object and reaches thermal equilibrium
Note: Common contact thermometry methods include thermocouple thermometry and resistance thermometry.
3.2
non-contact thermometry
temperature measurement method in which the temperature-sensing element is not in contact with the measured object
Note: Common non-contact thermometry methods include radiation thermometry and spectral thermometry.
3.3
embedded thermocouple
thermocouple whose measuring junction is designed to be embedded inside the measured object
3.4
rubbing thermocouple
thermocouple whose measuring junction remains in contact with the surface of the measured object at all times
3.5
infrared thermometry
measuring instrument that measures temperature by using the radiant flux of a thermal radiator in the infrared band
Note: One type of measuring instrument used in non-contact thermometry.
4 Measuring equipment
4.1 Measuring equipment for contact thermometry
4.1.1 The contact temperature measuring equipment shall meet the following requirements:
a) The EMF specifications and tolerances of the thermocouple selected based on the temperature range and environmental conditions shall meet the requirements of GB/T 16839.1;
b) The embedded thermocouple shall meet the requirements of GB/T 30429; the requirements for the rubbing thermocouple may refer to JB/T 5582.
4.1.2 See Annex A for the structural configurations of commonly used thermocouples.
4.2 Measuring equipment for non-contact thermometry
The non-contact temperature measuring equipment (infrared thermometry) shall meet the following requirements:
a) It shall be capable of continuously recording the temperature of the measured object;
b) It shall be designed to prevent lenses from being contaminated by dust, smoke, and other pollutants.
c) It shall be capable of withstanding an ambient temperature of not less than 70°C.
4.3 Display and recording device
The device for displaying and recording the dynamic temperature of the brake shall meet the following requirements:
a) It shall be capable of self-calibration (automatic compensation);
b) The indication error shall be less than 3% of the measured value;
c) The dynamic response time shall not exceed 0.2 s.
5 Thermocouple installation
5.1 Embedded thermocouple
5.1.1 Installation on the brake lining assembly
5.1.1.1 For the brake shoe assembly, the measuring junction of the thermocouple shall be installed at a location adjacent to the point of maximum load on the brake lining of the leading shoe assembly. When ribs, heat-dissipating fins, grooves, or rivet holes are present at this location, the position shall be offset by more than 5 mm.
5.1.1.2 For a pad assembly, the measuring junction of the thermocouple shall be installed at the center of the brake lining in both the length and width directions. When the brake lining has a groove, the position shall be adjusted, along the center of the friction track on the working surface, to a location on the rotating-out side that is not less than 7.5 mm from the groove edge; when temperature measurement is required for the brake lining in contact with the piston and the above arrangement is impractical, the position shall be adjusted, along the center of the friction track on the working surface, to a location on the rotating-out side that is not less than 5 mm from the edge of the effective piston action diameter on the pad assembly.
5.1.1.3 A through hole (whose aperture shall be determined by the outer diameter of the measuring junction of the thermocouple) shall be processed at the corresponding installation position. The measuring junction of the thermocouple shall be fixed in the hole without any looseness, and positioned (1±0.2) mm from the friction surface, as shown in Figures 1 and 2.
Contents of QC/T 556-2023
Contents
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Measuring equipment
5 Thermocouple installation
6 Installation of infrared thermometry
7 Measurement methods
Annex A (Informative) Structural configurations of commonly used thermocouples
