1 Scope
This standard is applicable to local calibration of such measuring equipments of temperature that have been installed at the site for oil transformer.
2 Normative References
The following standards contain provisions which, through reference in this text, constitute provisions of this standard. For dated reference, subsequent amendments to (excluding correction to), or revisions of, any of these publications do not apply. However, the parties whose enter into agreement according to these specifications are encouraged to research whether the latest editions of these labels are applied or not. For undated references, the latest edition of the normative document is applicable to these specifications.
JJG 310-2002 "Verification Regulation for Pressure Type Thermometer"
Q/GDW 168-2008 "Regulations of Condition-based Maintenance & Test for Electric Equipment"
DL/T 572 "Operation Specification for Power Transformer"
JB/T 6302-2005 "Oil-surface Thermometers for Transformers"
JB/T 8450-2005 "Thermometers for Transformer Windings"
3 Terms and Definitions
3.1
Measuring equipment of temperature
It is the generic term of the temperature measurement system consisted of in-situ pointer thermometer (including oil surface thermometer and winding thermometer) and remote display devices (including temperature element and temperature transmitter) mating with the oil transformer (reactor and converter transformer).
3.2
Pointer thermometer
It is the pressure type thermometer used for measuring the oil temperature and winding temperature of oil transformer (reactor and converter transformer).
3.3
The measure range of pointer thermometer
It is the absolute value of the difference between the upper limit and lower limit of the scale range of pointer thermometer.
3.4
The valid measure range
It is the usual temperature measure range defined based on the upper limit 105℃ of Class A insulation and heat resistance of oil transformer.
3.5
Zero adjusting for pointer
It is a regulation method that the indication of a calibration point is corrected by moving the pointer.
3.6
Multi-points zero adjusting
It is the piece-wise linearization regulation done for several indication setting points of the remote display device based on the indication of local pointer thermometer that meets the error requirements.
3.7
The error between local thermometer and far thermometer
It is difference between the remote displayed value and the indication of the in-situ pointer thermometer.
3.8
Compound sensor
It is the combined type sensor by assembling the temperature bulb of pointer thermometer and the far temperature element into one entirety.
4 General
The measuring equipment of temperature consists of pointer thermometer, remote display device, and so on, and the block diagram hereof is detailed in Figure 1.
Contents
Foreword II
1 Scope
2 Normative References
3 Terms and Definitions
4 General
5 Technical Requirements
5.1 General Technical Requirements
5.2 Measuring Performance Requirements
5.3 Calibrating Devices
5.4 Calibration Conditions
5.5 Calibration Items
6 Calibration Methods
6.1 Appearance Inspection
6.2 Insulation Resistance
6.3 Indication Error between Pointer Thermometer and Remote Display
6.4 The Error between Local Thermometer and Far Thermometer
6.5 Actuated Error of Connection Point
7 Treatment of Calibration Result
8 Calibration Cycle
Appendix A (Normative) Format of Calibration Record
Appendix B (Normative) Format of Calibration Certificate
Appendix C (Normative) Specification for Thermometer Purchase
Appendix D (Informative) Thermal Simulation Test of Winding Thermometer
Appendix E (Informative) Ambient Temperature Influence Quantity Test
Appendix F (Informative) Guideline for Temperature Protection of Oil Transformer
