1 Subject content and scope of application This standard specifies the terms and definitions, product classification, technical requirements, test methods, inspection rules, signs, packaging, etc. of industrial bimetal thermometers (hereinafter referred to as thermometers).
This standard applies to temperature sensing components consisting of bimetallic components and sheaths, with a circular dial and a thermometer with a measuring range of -80 to +500 Â°C.
2 reference standard
ZBY 002 Instrumentation, transportation, transportation and storage basic environmental conditions and test methods
ZBY003 Instrumentation Packaging Technical Conditions
ZBY120 industrial automation instrument working conditions - temperature, humidity and atmospheric pressure
ZBY122 Industrial automation instrument pointer indication part of the basic type, size and general technical requirements of the pointer
ZBY123 General rules for industrial automation instrumentation
ZBY247 Industrial Automation Instrument Terminology
3 Terms and definitions In addition to ZB Y247, the following terms and definitions apply to this standard.
3.1 The angle detection element axis is perpendicular to the dial plane, also known as the axial type.
3.2 Straight type of detection element parallel to the plane of the dial, also known as radial type.
3.3 Insert length from the lower end of the test element to the length of the mounting joint or the lower end of the taper thread (see L in Figure A1 to A4 in Appendix A).
3.4 Placement length From the lower end of the detection element, the length of the detection element in the measured medium.
4 product classification and basic parameters
4.1 The type thermometer is divided into the following four types according to the different installation methods of the indicating device and the detecting component;
d. Angle Mechanical and Electronic Industry Department 1988-06-12 Approved --------1989-01-01 Implementation
4.2 dial plate nominal diameter thermometer dial nominal diameter is 60,100,1500mm
4.3 Measurement range The measurement range of the thermometer shall comply with the requirements of Table 1.
-80 to +40
-40 to +80
0 to 50
0 to 100
0 to 150
0 to 200
0 to 300
0 to 400
0 to 500
4.4 Accuracy grade thermometers have an accuracy rating of 1, 1.5, (2.5)
Note: The accuracy level in parentheses is not recommended.
4.5 The diameter of the test component and the diameter of the mounting thread detection component and the installation thread shall comply with the requirements of Table 2.
Dial nominal diameter detection element diameter mounting thread
100, 1508, 10M27 Ã— 2
4.6 Insert length The insertion length of the thermometer is 75, 100, 150, 200, 250, 300, 400, 500 mm.
Note: If the insertion length is greater than 500mm, it shall be agreed between the manufacturer and the user.
The nominal pressure of the 4.7 jacketed nominal pressure thermometer jacket shall be selected from the series of 1.0, 1.6, 2.5, 4.0, 6.4 MPa.
4.8 Installation connection method The installation and connection method of the thermometer is divided into the following four types (see Appendix A);
a. adjustable pipe joints;
b. pipe joint (external thread);
c. pipe joint (internal thread);
d. Fix the thread.
4.9 Instructing the adjustment mechanism The thermometer is divided into the following three types according to the indication device:
a. No indication adjustment mechanism;
b. external indication adjustment mechanism;
c. Internal instruction adjustment mechanism.
5 technical requirements
5.1 Normal working conditions The normal working conditions of the thermometer shall comply with the requirements of Table 3.
Workplace temperature Â°C relative humidity%
Covering place -25 ~ +555 ~ 100
Outdoor place -40 ~ +855 ~ 100
Note: Special working conditions are agreed between the manufacturer and the user.
5.2 Appearance, Structure and Assembly Quality The appearance, structure and assembly quality of the thermometer shall comply with the following requirements:
a. The parts of the thermometer shall not be rusted, and the protective layer shall be firm, uniform and smooth;
b. The glass or other transparent material on the surface of the thermometer shall be transparent and free of defects that impede correct reading;
c. The type, basic parameters and dimensions of the thermometer (dimensional tolerances shall be in accordance with the relevant regulations of the manufacturer) shall comply with the provisions of Chapter 4;
d. The pointer and dial of the thermometer shall comply with the provisions of ZBY122 and ZBY123; the length of the pointer (the center of rotation of the pointer to the length of the indicating tip) shall comply with the provisions of Table 4; the distance between the indicator portion of the pointer and the plane of the dial shall be no greater than 5mm; partial circle with a circular scale of 270Â° to 300Â°; pointers, dials and scales and markings shall not discolor and fade.
Table 4 dial dial nominal diameter pointer length
5.3 Basic error limits The basic error limits of thermometers shall be in accordance with Table 5.
Table 5 accuracy level basic error%
1.0 of the range of Â±1.0
1.5 range of Â±1.5
(2.5) Â±2.5 of the range
5.4 The hysteresis thermometer should have a hysteresis that is not greater than the absolute value of the basic error limit.
5.5 Repeatability The repeatability of the thermometer shall not be greater than one-half of the absolute value of the basic error limit.
5.6 The detection element of the thermal stability thermometer shall comply with the requirements of 5.3 after the measurement upper limit is maintained for the time specified in Table 6.
Measuring upper limit Â°C holding time h
The time constant of the 5.7 time constant thermometer should be no more than 40s.
5.8 Vibration resistance thermometer should be able to withstand the frequency of 25Hz, displacement amplitude of 0.6mm, vibration waveform is sine wave, a total of 24h vibration resistance test. After the test, the thyometer should still comply with the provisions of 5.3, and there is no mechanical damage.
5.9 Position influence The indication value change caused by the thermometer tilting 90Â° forward, backward, left and right from the reference working position shall not exceed the absolute value of the basic error limit.
5.10 The jacket of the pressure-resistant thermometer shall withstand a withstand voltage test of 1.5 times the nominal pressure without damage or leakage.
5.11 Transportation, transportation and storage Basic environmental conditions The thermometer with factory packaging shall be able to withstand the high temperature (+55 Â°C), low temperature (-40 Â°C), continuous impact (acceleration: 98 m/s2, pulse duration: 11 ms) according to ZBY002 and Free fall (height: 250mm) test. The test shall still comply with the provisions of 5.2, 5.3, 5.4 and 5.5.
6 test methods
6.1 Appearance, structure and assembly quality inspection shall be carried out by visual inspection and corresponding tools in accordance with the requirements of 5.2.
6.2 Basic error limit test
6.2.1 Test conditions
a. The ambient temperature is 15 to 35 Â° C, the relative temperature is 45% to 75%, and the atmospheric pressure is 86 kPa to 106 kPa;
b. The length of the thermometer should be in accordance with the requirements of the product manual;
c. No backlash and vibration.
6.2.2 Test equipment and standard instrument The test equipment is a constant temperature bath, and the standard instrument is a standard thermometer. When measuring the temperature of the bath, the limit error of the measurement method used shall not exceed one quarter of the basic error limit of the test thermometer.
6.2.3 Test points Each thermometer shall have a test point of not less than 4 and shall be evenly distributed over the long scale line within the measurement range (including the upper and lower limits of measurement and 0 Â°C).
6.2.4 Test requirements Insert the test element of the test thermometer and the standard thermometer into the constant temperature bath. The temperature of the bath should be stable at the specified test point temperature, read by the standard thermometer, and then read the value of the test thermometer.
The difference between the measured value of the test thermometer and the standard thermometer is the basic error of the thermometer at the test point.
At least one test shall be carried out at each test point along the forward and reverse strokes, and the results of each test shall comply with the provisions of Article 5.3.
6.3 Hysteresis test The backlash test uses the same test conditions, test equipment, standard instruments, test points (except the upper and lower limits measured) and methods, and is carried out simultaneously with the basic error limit test. The difference between the indication values â€‹â€‹of the positive and negative strokes at each test point is the hysteresis of the thermometer, which shall comply with the provisions of 5.4.
6.4 Repeatability test The repeatability test uses the same test conditions, test equipment, standard instruments and test points as the basic error limit test. The indications shall be read at least three times at each test point along the same stroke (forward or reverse stroke). The maximum difference between the values â€‹â€‹indicated at each test point along the same stroke is the repeatability of the thermometer, which shall comply with the provisions of 5.5. At the same time, it should still comply with the provisions of 5.3, 5.4.
6.5 Thermal stability test The test element of the thermometer is inserted into the thermostat, and the upper limit of the measurement is maintained for the time specified in Table 6. During the test, the temperature of the thermostat should not exceed Â± 2 Â° C. After the test, the thermometer should still comply with the provisions of 5.6.
6.6 Time constant test The test element of the thermometer is in a medium with a lower temperature. After the value is stable, it is quickly moved into a thermostat with a higher temperature (the difference between the temperature of the former medium and the temperature of the bath is greater than the thermometer) 50% of the range to form a temperature step), while starting the stopwatch, when the change in the indication value of the bimetal thermometer reaches 63.2% of the temperature difference (step value), the stopwatch is embedded. The time recorded by the stopwatch is the time constant, which should meet the requirements of 5.7.
6.7 Vibration resistance test The thermometer is mounted on a vibration table. The thermometer's dial should be parallel to the gravitational acceleration. It is then subjected to vertical vibration in accordance with 5.8.
6.8 Positional impact test The thermometer at room temperature is tilted 90Â° from the front, back, left and right of the reference working position, and then the resulting change in indication is measured.
6.9 Withstand voltage test The pressure test of the thermometer sheath shall be carried out by external pressure test at room temperature. The test pressure is 1.5 times the nominal pressure and the test time is 1 min. The sheath shall be free from damage and leakage during the test.
6.10 Basic environmental conditions test for transportation, transportation and storage The thermometers with factory packaging shall be tested for high temperature, low temperature, continuous impact and free fall according to the provisions of ZBY002 and 5.11.
7 inspection rules
7.1 Factory inspection Each thermometer shall be factory tested according to the requirements of 5.2 and 5.3 and the test methods of 6.1 and 6.2. A thermometer that has passed the factory inspection can be shipped from the factory and should be accompanied by a certificate.
7.2 Inspection thermometers shall have one of the following conditions and shall be type tested:
a. When a new product is trial-produced or an old product is transferred to the factory for production;
b. After formal production, if there are major changes in structure, materials and processes, which may affect product performance;
c. During normal production, periodically or after accumulating a certain amount of production, a test shall be carried out periodically;
d. After the product is discontinued for a long time, when the production is resumed;
e. When the factory inspection result is significantly different from the previous type inspection;
f. When the national quality supervision agency requests the type inspection.
8 logo, packaging
The following signs shall be placed on the dial of the 8.1 mark thermometer:
a. manufacturer name or factory mark;
b. product name;
c. product model number;
d. Measurement unit symbol "Â°C";
e. accuracy level;
f. Product number and manufacturing year and month.
8.2 Packaging Bimetal thermometers shall be packaged in accordance with ZBY003.
Hot products: metal rotor flowmeter , magnetic flap level gauge , plastic tube float flowmeter , steam vortex flowmeter , float level gauge .
Arborist Rope,Arborist Climbing Rope,Arborist Bull Rope,Arborist Rigging Rope
Baoying Yiliyuan Rope And Net Co.,Ltd , http://www.ylyropes.com