CN104375109B - A kind of self calibration method of testing of resistance load coefficient - Google Patents
A kind of self calibration method of testing of resistance load coefficient Download PDFInfo
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- CN104375109B CN104375109B CN201410357458.2A CN201410357458A CN104375109B CN 104375109 B CN104375109 B CN 104375109B CN 201410357458 A CN201410357458 A CN 201410357458A CN 104375109 B CN104375109 B CN 104375109B
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Abstract
The present invention provides a kind of self calibration method of testing of resistance load coefficient, the test for the self calibration of resistance load coefficient and other resistance load coefficients.This method constructs four different line overall electrical resistances of two structures with multiple miniature resistance elements of same resistance with model first, the main points of construction are that the load of the resistive element in each overall electrical resistance as the load of each resistive element, but in different overall electrical resistances is different；Miniature resistance element used is tested in advance, ensures that temperature characterisitic is consistent.Then, the load factor of the two resistance is measured with comparator for direct current DCC electric bridges；DCC electric bridges are in the working condition do not restarted in whole measurement process.The present invention solves the difference that two resistance load coefficients can only be obtained in conventional test methodologies and the not high problem of measurement accuracy, any one above-mentioned resistance can be used as reference resistance known to load factor, recycle DCC bridge measurements to go out the load factor of other measured resistances.
Description
Technical field
The present invention relates to a kind of self calibration method of testing of resistance load coefficient, and in particular to a kind of resistor load coefficient
Self calibration and the method tested using the resistance that self calibration is crossed as reference pair other resistance load coefficients.
Background technology
Resistance can cause temperature rise because of heating, cause resistance to change in the presence of load current, this existing
Load effect as being referred to as resistance；For quantitative description, resistance relative variation when typically resistance power consumption being unit power
The referred to as load factor of resistance.The unit of resistance load coefficient is (Δ R/R)/W.The load effect and many factors of usual resistance
It is relevant, current density, the physical dimension of resistance, heat dispersal situations and the coiling situation born such as resistance material, the material of skeleton
With the factor such as physical dimension, the species of surrounding medium and state.
The measuring method of traditional resistor load factor mainly has unequal arm bridge method, precision voltage divider method and DC potential difference
Meter method.Wherein, unequal arm bridge method is to determine load factor by changing bridge output voltage, but can only so obtain two
The difference of resistance load coefficient, it is impossible to obtain the absolute figure of load factor；Although precision voltage divider method and DC potentiometer method
Other influences of related resistors load factor to measurement result are eliminated, but the measurement error of electric current limits accuracy of measurement
Further improve.
Therefore, the measure of resistance load coefficient is that the technology that field of electrical metrology fails to solve very well always for many years is asked
Topic, how the load factor of accurate measurement resistance, be hyundai electronicses meter accurately to assess influence of the load effect in metering
It is badly in need of the technology " bottleneck " captured in amount field.
The content of the invention
The present invention is in order to solve the technical problem of above-mentioned Accurate Determining resistance load coefficient, it is proposed that a kind of ohmic load system
Several self calibration method of testings.
This method is multiple miniature resistance Series Parallel Elements with same resistance and model and the four-wire ohm that is integrally formed,
The voltage drop of wherein each resistive element is the same when the main points of construction are galvanizations in the current feed for make this overall electrical resistance, because
As the load of this each resistive element.Miniature resistance element used should be tested in advance, ensure that its temperature characterisitic is consistent.
With different series-parallel system two structures as constructed above different four-wire ohm A and B.When the two marks
When quasi- resistance is compared measurement with comparator for direct current (DCC) electric bridge, the voltage on resistance A and resistance B voltage leads is
Equal, but to make the load of resistance A resistive element and the resistive element in resistance B different during construction.
It is as follows that self-alignment step is carried out to two four-wire ohms A and B：
First, using four-wire ohm A as measured resistance RXAccess the main winding N of the DCC electric bridgesPLoop, resistance B conducts
Reference resistance RSAccess the auxiliary winding N of the DCC electric bridgesSLoop, the cold end of the two four-wire ohms are connected, high potential
End is coupled with the highly sensitive zero indicator input of DCC electric bridges, and when zero indicator reading is zero, two ohmically voltages are U,
The resistance proportion of two resistance is
Number of turn ratio thereinCan directly it be read by electric bridge reading plotter.
Heating effect after being powered due to resistance, the now resistance of the two resistance original resistance R with not adstante febreX0
And RS0There is difference.Have when being formulated
RX=RX0(1+α) (2)
RS=RS0(1+β) (3)
Factor-alpha and β in formula mean that influence of the heating to A and B overall resistances.Due to each element in resistance A
All, temperature coefficient is also identical, therefore factor-alpha is also represented due to each component resistance in resistance A caused by heating for load
The relative change of value.Due to same cause, factor-beta is also represented due to each element resistance value in resistance B caused by heating
Relative change.
Due to being had been noted that in construction to A and B with different series-parallel systems so that resistance A resistive element
It is different with the voltage of the resistive element in resistance B.If the voltage in resistance A on each element is u1, in resistance B on each element
Voltage be u2, both ratio is
It should be noted that even if the output voltage change of comparator for direct current (DCC) electric bridge, u1And u2And proportional change
, i.e. its ratio ξ does not change with the change of DCC electric bridges.
Heating on resistive element is directly proportional to ohmically voltage squared, therefore can be obtained
Operation in next step is to keep electric bridge to be constantly in open state, by the output voltage of electric bridge, that is, two resistance
Load voltage, change into U ' from U, change ratio is
Similarly, since the heating of resistance is directly proportional to ohmically voltage squared, the strain of (2) and (3) formula into
R'X=RX0(1+αη2) (7)
R'S=RS0(1+βη2) (8)
R'XAnd R'SIt is bridge output voltage after U changes into U ', the new resistance caused by resistance heating changes
Value.
When electric bridge zero indicator reaches balance again, the ratio of two resistance is
Equally, number of turn ratioAlso can directly be read by electric bridge reading plotter.Show through domestic and international many experiments, when
DCC electric bridges are constantly under open state, and the relation between current ratio and number of turn ratio is highly stable, so as to ensure that self-correcting
The accuracy of quasi- process.
It can be obtained by (1) to (9) formula
It is, in general, that resistance value is very little with respect to change because of caused by heating, that is to say, that factor-alpha and β are very
Small amount.Now (10) formula can be further simplified as
Factor-alpha in formula represents influence of the heating to A overall resistances.The factor needed for us is solved from (11) formula
α, while also can use (5) formula to obtain factor-beta, i.e.,：
Factor ξ in α formulas on denominator is (see (4) formula) by resistance A and B structures shape, and factor η is in test process
In given (see (6) formula), the factor gamma on molecule1And γ2It is that (see (1) and (9) formula) is read by electric bridge, is all and understands to measure.
Resistance A relative change α values and resistance B relative change β value thus can be obtained by (12) formula, and then can unit of account power
When resistance relative variation, i.e. resistance load factor.Complete and two four-wire ohms A and B load factor are carried out certainly
The step of calibration.
Note that, the key that can complete above-mentioned self-calibration process is
1. the four-wire ohm being integrally formed with multiple miniature resistance Series Parallel Elements of same resistance and model.Make this
The voltage drop of wherein each resistive element is the same during galvanization in the current feed of overall electrical resistance, therefore each resistive element is negative
Carry the same.Miniature resistance element used should be tested in advance, ensure that its temperature characterisitic is consistent.
2. with different series-parallel system two structures as constructed above different four-wire ohm A and B.When the two
When measuring resistance is compared measurement with comparator for direct current (DCC) electric bridge, the voltage on resistance A and resistance B voltage leads
It is equal, but makes the load of the resistive element in resistance A and the resistive element in resistance B different during construction.
3. thus obtain (5) formula of key.For the resistance of other forms, this is difficult to.This addresses the problem
The difference of two resistance load coefficients and the problem that measurement accuracy is not high can only be obtained in conventional test methodologies.
After completing above-mentioned load factor self calibration test, any one in two resistance A and resistance B can conduct
Reference resistance known to load factor, utilize comparator for direct current (DCC) electric bridge, same to said process, so that it may measure tested
The relative change of resistance：
α is load factor known to reference resistance, and factor η is to be given in test process (see (6) formula), γ1And γ2
It is that (see (1) and (9) formula) is read by electric bridge, is all and understands to measure.The relative change of measured resistance can be thus obtained by (13) formula
Change β1Value, so can unit of account power when resistance relative variation, i.e. resistance load factor, so as to complete to tested
The test of resistance load coefficient.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is the required accompanying drawing used in technology description to be briefly described.It should be evident that the accompanying drawing in following description is only this
Some embodiments of invention, for those of ordinary skills, can also be obtained according to these accompanying drawing illustrated embodiments
Other embodiments and its accompanying drawing.
Fig. 1 is the resistance junction composition of the present invention；
Fig. 2 is the resistance self calibration scheme schematic diagram of the present invention；
Fig. 3 is 100 Ω resistance junction compositions of the embodiment of the present invention two；
Fig. 4 is 20 Ω resistance junction compositions of the embodiment of the present invention two.
Embodiment
Clear, complete description is carried out to the technical scheme of various embodiments of the present invention below with reference to accompanying drawing, it is clear that described
Embodiment be only the present invention section Example, rather than whole embodiments.Based on the embodiment in the present invention, this area
Those of ordinary skill's all other embodiment resulting on the premise of creative work is not made, belongs to institute of the present invention
The scope of protection.
When determining resistance load coefficient, the structure of resistance is carried out first.In the present embodiment, resistance employs two kinds of different knots
The four-wire ohm A and B of structure, they are combined by multiple miniature resistance elements of same resistance and model, and these are small-sized
Resistive element is by strict screening, to ensure that its temperature characterisitic is consistent.Wherein, resistance A uses " parallel connection " structure of multiple element,
As shown in Figure 1a；Resistance B then uses " series-parallel connection " structure of multiple element, and " series-parallel connection " refers to first connecting several elements, when
Make a cell to use, then these cells are together in parallel, as shown in Figure 1 b；Either first some elements are distinguished
And be unified into two cells and be together in series, finally it is together in parallel again, as illustrated in figure 1 c.Element in resistance B in this instance
On voltage be resistance A in element on voltage half, that is to say, that (5) factor ξ values in formula are
After the structure for completing resistance, so that it may carry out self calibration to the load factor of resistance, that is, determine the load factor of resistance.
In the present embodiment, resistance A, B self calibration scheme principle are as shown in Fig. 2 employ comparator for direct current electric bridge (abbreviation DCC)
Structure.The operation principle of DCC electric bridges is current transformer core ampere-turn equilibrium, i.e., in a super-magnetic conducting rate, the ring of low magnetism leakage
With opposite polarity coiling main winding N on shape iron corePWith auxiliary winding NS, main winding passes to direct current constant current IP, auxiliary winding passes to another
Constant current IS, in the case where ampere-turn is equal, reach balance：
NP×IP=NS×IS (15)
I.e.
A detection winding is wound with simultaneously on iron core, with square wave excitation, can obtain ampere-turn by detecting second harmonic is
No balance, if not balancing, the automatic follow current source for changing auxiliary winding causes ampere-turn to reach balance.Can from formula (16)
Going out, the ratio of ultimate current is equal to the inverse ratio of the number of turn, and the number of turn is will not to be influenceed and changed by any factor, therefore from principle
Say, DCC electric bridges can measure the ratio value of electric current with high accuracy, and then can obtain the ratio value of resistance.
In the present embodiment, as shown in Fig. 2 resistance B is reference resistance RSAccess the auxiliary winding N of current comparatorSLoop, electricity
Resistance A is to make measured resistance RXAccess main winding NPLoop.The cold end c2 of two resistance links together, and c1 points of high order end
Highly sensitive zero indicator input is not connected to.When zero indicator reading is zero, the ohmically voltage U of A, B two are equal, i.e.,：
U=IS×RS=IP×RX (17)
It can obtain：
Namely：
Then electric bridge is kept to be in open state, by the output voltage of electric bridge, that is, the load electricity of two overall electrical resistances
Pressure, U ' is changed into from U, be to take the change ratio to be during specific implementation
When zero indicator reaches balance again, resistance ratio γ is obtained2.With ξ, γ in (14), (19), (20) formula1, η mono-
Act (12) formula of substitution, so that it may
And then the load factor of the resistance relative variation, i.e. resistance when can calculate measuring resistance A and B unit power.It is complete
Into after the load factor self calibration test of resistance, wherein any one can be used as reference resistance known to load factor, profit
With comparator for direct current (DCC) electric bridge, so that it may measure the load factor of measured resistance.When measuring load voltage U first
Resistance ratio γ1(see (19) formula)；Secondly U changes into U ', takes change ratio η (see (20) formula) during specific implementation, works as zero indicator
When reaching balance again, resistance ratio γ is obtained2；Take the relative change α of known reference resistance；(13) formula of substitution, can be obtained
And then can unit of account power when resistance relative variation, i.e. resistance load factor.
Specific implementation process is described below.Fig. 3 and Fig. 4 is four-wire ohm used in embodiments of the invention, the electricity
Resistance employs the Ω resistance of RX70 types 500 of commercial manganese-copper filament coiling, by testing same producer with a batch of 500 Ω resistance
Temperature characterisitic, the consistent some resistance of characteristic are strictly picked out.The structure and self calibration of resistance are carried out first, according to Fig. 3 institutes
The method shown, the resistive element for being 2000 Ω into a resistance 4 500 Ω resistance components in series, 20 such elements
And it is unified into the four-wire ohm that a resistance is 100 Ω；Again as shown in figure 4,2 500 Ω resistance components in series are got up as one
The individual Ω of resistance 1000 resistive element, each 25 such elements of two rows respectively and are then unified into two 40 Ω resistance, most
The four-wire ohm for being afterwards 20 Ω into a resistance the two 40 Ω resistor coupled in parallel.
The temperature curve of manganese-copper filament resistive element used in the present embodiment is a conic section that Open Side Down, is led to
The temperature of oil groove where changing resistance is crossed, measures the summit i.e. zero temperature coefficient point of its temperature curve at 24.1 DEG C.In the reality
Apply in example, above-mentioned 20 Ω and 100 Ω resistance is put into same oil groove, using 20 Ω resistance as reference resistance RS, with 100 Ω
Resistance is measured resistance RX, DCC electric bridges are connected to by Fig. 2 mode of connection.Change the temperature of oil groove, compare this two resistance not
Multiple averaging method and symmetrical observation method are employed with the ratio under load voltage, during test to reduce the influence of reading dispersiveness,
Test result is as shown in table 1.
Electric bridge reading result when the different temperatures of table 1 and different bridge output voltages
It can be seen that at 24 DEG C, the relative difference of electric bridge reading is 5.6 × 10-9.(21) formula of utilization, when can draw 1V
The relative change of 20 Ω resistance is 1 × 10-8, and the relative change of 100 Ω resistance is 2.5 × 10-9；Or 20 Ω resistance load system
Number is (2 × 10-7)/W, and the load factor of 100 Ω resistance is (2.5 × 10-7)/W.In addition it can be found that in different temperature
Under, the relative difference of electric bridge reading is slightly different, and it is manganese-copper filament resistance that this, which is primarily due to above two resistance, and its resistance is zero
Temperature coefficient point is nearby into parabolic shape, the not quite identical result of temperature coefficient.
After the self calibration for completing resistance load coefficient, so that it may the load of other measured resistances is measured as reference resistance
Coefficient.Listed in table 2 by the use of by self-alignment 100 Ω measuring resistances and, as during reference, measure the test of 1k Ω measured resistances
As a result.Measure 3 times and average, and the relative change α of 100 Ω resistance is 2.5 × 10-9 during known 1V, substituting into formula (22) must
To the relative change β of 1k Ω resistance during 1V1It is 3.6 × 10-8, or the load factor of 1k Ω resistance is (3.6 × 10-5)/W, from
And complete the test to the resistance load coefficient.
The Ω resistance of table 2 100 is result when reference pair 1k Ω measured resistances are tested
Obviously, those skilled in the art can carry out the spirit of various changes and modification without departing from the present invention to the present invention
And scope.So, if belonging to the scope of the claims in the present invention and its equivalent technologies to these modifications and variations of the present invention
Within, then the present invention also comprising these change and modification including.
Claims (2)
1. a kind of self calibration method of testing of resistance load coefficient, it can carry out the self calibration of resistance load coefficient and other electricity
Hinder the test of load factor, it is characterised in that turned into not with multiple miniature resistance Series Parallel Elements of same resistance and model
Same overall four-wire ohm so that in the current feed of overall four-wire ohm during galvanization, the resistance of the overall four-wire ohm
The voltage drop of element is the same, so that as the load of each resistive element, wherein, it is each in different overall four-wire ohms
Voltage on resistive element does not change into a fixed ratio ξ, the fixed ratio ξ with the change of DCC bridge output voltages, institute
Miniature resistance element should be tested in advance, ensure that its temperature characterisitic is consistent；
Wherein, the overall four-wire ohm A and B of two different structures is constructed with different series-parallel systems, when the two entirety four
When line resistance is compared measurement with DCC electric bridges, the voltage on overall four-wire ohm A and overall four-wire ohm B voltage leads is
Equal, but the load of the resistive element in overall four-wire ohm A and the resistive element in overall four-wire ohm B is different；
After forming overall four-wire ohm A and overall four-wire ohm B, load factor self calibration testing procedure is as follows：
(1) overall four-wire ohm A and overall four-wire ohm B ratio γ is determined with DCC electric bridges1；
(2) size of resistance A and resistance B input voltages is changed, again with DCC bridge measurements entirety four-wire ohm A and overall four
Line resistance B ratio γ2, DCC electric bridges are in the working condition do not restarted in whole measurement process；
(3) two ratio value γ of gained are utilized1And γ2Calculate overall four-wire ohm A and overall four-wire ohm B load system
Number.
2. according to the method for claim 1, it is characterised in that whole after completing above-mentioned load factor self calibration test
Any one in body four-wire ohm A and overall four-wire ohm B can be used as reference resistance known to load factor, recycle DCC
The load factor of other measured resistances of bridge measurement.
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Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN105067886B (en) * | 2015-07-15 | 2017-11-03 | 北京东方计量测试研究所 | A kind of method and apparatus for measuring resistance load coefficient |
| CN105004927B (en) * | 2015-07-15 | 2018-08-03 | 北京东方计量测试研究所 | Bridge-type resistance and its application |
| CN108008193B (en) * | 2017-11-29 | 2020-02-07 | 北京东方计量测试研究所 | Combined quantum Hall resistance sample proportion checker |
| CN114061799B (en) * | 2021-11-08 | 2022-09-16 | 珠海格力电器股份有限公司 | Wheatstone bridge and multidimensional force sensor |
| CN115792381B (en) * | 2022-11-24 | 2023-06-23 | 中国计量科学研究院 | Device and method for precisely measuring load coefficient by adopting combined quantum Hall resistor |
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