This standard is applicable to the manufacture of nickel-chromium-gold-iron and copper-gold-iron low-temperature thermocouple wires. GB/T 2904-1982 Nickel-chromium-gold-iron, copper-gold-iron low-temperature thermocouple wires and graduation tables GB/T2904-1982 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Nickel-Chromium/Gold-fron,Copper/Gold-IronIowtemperature thermocouple wires and their reference tablesUDC 621.362.1
GB2904—82
This standard applies to the product varieties, specifications and basic parameters of chrome-chromium/gold-fron,copper/gold-iron low-temperature thermocouple wires (hereinafter referred to as couple wires).
1.1 Name of couple wires. Code and Nominal Composition The name, code and nominal composition of the wire are shown in Table 1: Table 1wwW.bzxz.Net
Gold-iron alloy wire
Nickel-chromium alloy wire
Wire diameter and filling difference
Nominal composition
Au+Original percentage 0.7Fe
90 %Xi, 10 %C-
100%Cu
Wire diameter and its allowable deviation meet the requirements of Table 2. The roundness of the wire shall not exceed the allowable deviation of its diameter. Table 2
Note: According to the user's requirements, it is allowed to supply wires of other diameters. 1.3 Wire grade
According to the allowable deviation range of thermoelectric characteristics, the wire is divided into I and II grades. The grading conditions are shown in the technical requirements. 1.4 Graduation and operating temperature range diagram and label The graduation and operating temperature range of the thermocouple composed of thermocouple wire are shown in Table 3; Table 3
Nickel-iron
Copper-gold
National Standards Bureau 1982-D2-16 Issued
NiCr-Aure
Cu-AuFe
Using temperature range
—270 ~
270 ～ --196
1982-10-D1 Implementation
The label of thermocouple wire is as follows:
GB2904-82
The industrial grade gold-iron thermocouple wire with a diameter of 0.2mm is labeled: Au0.2 1GB 2904-82
The grade II nickel-chromium wire with a diameter of 0.2mm is labeled AiCr-0.2GB2901-82
The grade I copper wire with a diameter of 0.2mm is labeled Cu-0.2 IGB 2904-82
2 Technical requirements
2.1 Surface quality
The surface of the wire should be smooth, oil-free, fold-free, crack-free, and burr-free. Small marks and depressions that do not exceed the diameter tolerance are allowed.
The surface of the enameled wire should be smooth, the paint layer should be uniform, and there should be no bubbles and impurities in the paint layer. A small amount of dispersed particles is allowed. 2.2 Breakdown voltage of enameled wire
The breakdown voltage of enameled wire: should be no less than 900 volts. 2.3 Thermoelectric characteristics and allowable deviations
For thermocouples composed of wires, when the temperature of the test end is 0°C, the relationship between the temperature and the thermoelectric potential is shown in Table 4 or Table 5, and the allowable deviation shall not exceed that specified in Table 6.
2904—82
[98*0--
002:0-
Sler'-
OFt --
668-0-
f88*:-
Fiig'& -
ZE8'0-
4561-7-
F28'E-
199'1—
#10'T-
#62'0-
ESI '0-
281—
820*F-
F88\2--
289°2
689'1-
098'1-
9G9° -
+t9*#:-
F90*S-
6997--
152-0—
680*0-
629---
0[8 *6-
FEP-S:
290*0-
00:—
5:91*s
997~0-
2EE-9-
Hi'P :
PEF*:
822: 5:-
292:1-
bo6'0-
781*#:
291°7
21E:1-
788'4-
S1*:27-
290482
069° 1--
890'--
299°0-
f09'o-
16'0—
(OT*0-
igt * E-
108'0--
199'0
292*0-
291:0-
160*0-
FFO*O-
092*[-||tt ||950*0-
12R*0-
F99\0)-
2G8*--
181-0--
IFO'O-
299:1-
028*F-
E98'0-
989*0-
191- 0-
O21*n-
160'0-
FTO—
26#1--
202\0-||tt| |680*0-
290*0-
29'1—
066*0-
ZFR'0-
102- 0-
129'0-
STF'O-
Fl1*o-
690-0-
600°0||tt ||Fyk'l--
801:1--
心F0'1-
-6680--
b6a'6-||tt| |20z*0—
680:0-
990*0-
TEO-O-
S65'[-
86(1 1
100'1--
168~0-
205°0-
suo'心
002-0--
291- 0-
820°01
.t'+--
1x1:1--
ASS(I-
191-0-
151 - | —19
Uneven thermoelectric potential
The uneven thermoelectric potential of each couple wire at 196℃ shall not exceed the requirements of Table 7. Table 7
Uneven thermoelectric potential V
Couple name
Stability
The thermoelectric potential value measured at the liquid nitrogen point by the electric heating impulse method for the thermocouple composed of the main wire shall not change by more than 1uV. 2.6 Others
For the saturation performance of the couple wire, see Appendix A (reference) 3 Test method
3.1 Selection
3.1.1 Factory test Take 1.3 meters from the head and tail of each couple wire produced for inspection. 3.1.2 Type test Take at least three valve wires from the finished products and take 1.5 meters from the head, tail and tail for test. 3.2 Sample preparation
First, wipe and clean the selected adjustment wire with alcohol or ether in reverse. The optical wire should be covered with a clean metal sleeve. The insulation layer of the enameled wire should be completely removed from the test end and the reference end. Then weld it on an argon conductor: the contact point should be spherical, with a diameter of about 1 to 3 times the wire diameter. The surface should be smooth and free of oxidation, scratches, twists and turns, and the accuracy should be less than 0.3mm.01tnm only,
b. Low temperature tank: liquid nitrogen and liquid nitrogen comparison tank
Electrical measuring instrument, accuracy is not. Current laboratory low potential current potentiometer and its matching device, or other electrical equipment with equivalent accuracy.
d. Standard instrument: precision is not less than -0.02% low temperature temperature juice. e.
Pure platinum wire: platinum wire resistance ratio Wm=R2/R, ≥1.39\5: GB 2904-82
3.4 ​​Size inspection (Article 1.2)
The diameter of the wire should be inspected in two mutually perpendicular directions on the same cross section. At least three parts of each tube of wire should be inspected. 3.5 Surface quality inspection (Article 2.1)
The surface quality is observed with the naked eye.
3.6 Uneven thermoelectric potential (Articles 2 and 4) Weld one end of the sample to the same pure platinum wire or tie it with clean copper wire of Φ0.1-0.2mm diameter. When the reference end is 0℃, the temperature at the measuring end is -196℃. Measure the thermoelectric potential of platinum. The maximum difference is the uneven thermoelectric potential. 3.7 Thermoelectric characteristic test (Article 2.3)
Put the measuring end of the thermocouple sample at the same horizontal position as the middle of the temperature sensing element of the low overflow thermometer. The insertion depth is 200mm. When the temperature of the reference end is 0℃, measure in a low temperature tank by the comparison method of -196℃ and -269℃. During measurement, the temperature of the low temperature tank should be controlled within ±1℃ of the temperature measuring point, and the temperature fluctuation should not be greater than 0.01℃. 3.8 Stability test (Article 2.5)
The measuring end of the sample is subjected to a thermal cycle from liquid nitrogen (-269℃) to room temperature for five days. When the reference end temperature is 0℃ and the measuring end temperature is -296℃, the change in the thermoelectric potential before and after the thermal cycle shall not exceed 1μV. 3.9 Enameled wire breakdown voltage test
The enameled wire breakdown voltage is measured on a voltage breakdown tester. The test voltage is an alternating current with a nearly sinusoidal waveform and a frequency of 50 Hz.
Take a sample of about 500 mm in length and fold it in half three times, twist it 32 times on a length of 200 mm, cut off the bent end in the middle and separate it, apply the test voltage to the other end of the sample, and the voltage rises steadily from zero until the breakdown, and read the breakdown voltage value, with a voltage increase rate of 200 V/s.
4 Acceptance rules
4.1 Factory inspection
Electrode wires shall be inspected and qualified by the quality management department of the manufacturer and can only be shipped with a product certificate. The inspection items for delivery are:
a. Dimension inspection (performed in accordance with Article 3.4)b. Surface quality inspection (performed in accordance with Article 3.5).c. Uneven thermoelectric potential test (performed in accordance with Article 3.6).d. Thermoelectric characteristic test (performed in accordance with Article 3.7)4.2 Type test
Electrode wire type test shall not be less than once a year. The type test shall be carried out in accordance with all the test items of this standard. If one item fails, double the sample shall be thrown for re-inspection of all items. If there is still one item that fails, the type test is considered to be unqualified. If the production process is changed, a type test must be carried out: 5 Supply method, packaging and marking
5.1 Supplier
Electrode wire should be supplied in annealed state, each wire should be wound with one wire, and there should be no joints in the middle. Its weight should not be less than 20 grams. If the user needs it, it is allowed to supply electrode wire less than 20 grams. 5.2 Packaging
The positive and negative poles of the electrode wire should be wound on the wire roll respectively, the wire head should be fixed firmly, and the packaging should be firm. 5.3 Marking
5.3.1 Each coil of electrode wire should be marked:
8. Manufacturer name and trademark:
h. Product name, label and graduation number:
Product number:
Gross weight and net weight of each coil of electrode wire;
Year, month and day of manufacture.
GB 2904—82
The product certificate of each reel of twine wire contains the following marks: manufacturer name and trademark;
product name and number:
product number:
This product complies with GB2904—82 and ViCr-AuFe (or Cu—AuFc) graduation table; gross weight and net weight;
year, month and day of manufacture.
GB 2904---82
Appendix A
(reference)
A.1 When the reference end temperature is 0, the standard values ​​and allowable deviations of the thermal electromotive force of nickel-chromium-iron, pot-iron and its corresponding nickel-chromium-platinum, steel-platinum and gold-platinum at the main temperature points are listed in Table A1 and Table A2 respectively: Table A1
Nickel-chromium-iron
Pliers
Gold-iron-pin
Silk-iron
Gold-iron-drill
Measurement end temperature
Measurement end temperature
—196
C Standard value
Marking value mV
±0.00 yuan
±9,005
Thermal electromotive force range mY
--4.037 - -4.055
—1.028~~1.064
-5.261 +5.275
5.255 ~ -:.281
3.391~-3.399
-3.387 ~-3. 103
-3.353 -3.581
-3.549 -3.55
0.646 ~0.556
,61 ~0.651
1.708 1.714
1,706 ~1.716
Thermal electromotive force fan solid m
—9,859~-0.867
-0.355 ~**-0.871
-1.685 --1.99 :
1.679 -1.703
—0.230--0.214
0.208~-0.216
0.018~0.022
0.015~0.025
0.649 ~0.553
0,347 -0. 555
1.707 ~1.713
1.70.1 ~1.715
The mechanical properties are shown in Table A3.
For the conversion table of energy, see Table A4
GB 2904-82
kgf/rnrn2
kgf/mm?
(m)
The scale tables of nickel-chromium-iron and steel-iron with 0K as reference temperature are called Table A5 and Table A6. A.5For the scale tables of copper-iron and copper-iron with 0~100℃, see Table A7 and Table A8. A.6For the resistivity table of gold-iron (1~280K), see Table A9. A.7For the thermal conductivity table of gold-iron (3~280K), see Table A10. Calculation
The nickel-chromium-gold-iron graduation table given in Table 15 (with 0K as the reference temperature) is calculated from the following polynomial: Ma:t
t1 =6.9864426367
t2 2 9.0607276605 ×10 -1
43 -4.3469694773 X10-2
+ = 1.2468246660 ×10 -3
s -2.3500537590 x10 ~5
Qg3.0837610寸15×10
0，2.9032251684×10-9
ex =1.9881512159 x10 --11
Q=-9.9174829612×-14
Q10 -3.5645229362 -31
Gauge length 100
12-439
16,456
GB 2904—82
13 = -1.5093916059 ×10 -2:
Q146.8264293980×10-28
Table A5 Nickel-chromium-gold-iron thermocouple graduation table
(with 0 as reference temperature)
17--89
206 yuan.91
2322,1F
2931,00
GB 2904—82
Continued Table A5
22:164
32904-82
The copper-gold-iron graduation table given in Table A6 (with 0K as reference temperature) is calculated by the F-column polynomial: ati
, =6.9819441789
(2 =8.4001378651 ×In -1
(3 =-4.5417070202 ×10-2
Q=l.3796048892X10-3
us =-2.7648679333 × 10 -5
Q3.8534874955×10-7
a=-3.8382718939×10-9
Q piece=2.7684122233×10-11
Qg=-1.4483161512× 10-13
71o -5.4390389051 X10-16
Qll-1.4282076268x10-1x
01g =2.4882871621 10 -21
a1: = -2.5831198571 ×10-24
Qu=1.2089129004×10- 27
Table A6 Copper-gold-iron thermocouple graduation table
(with 0K as reference temperature)
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