Tensile strength machine is precision equipment, from production to handling and then to installation of each link need to be extra careful, introduce the following tensile strength machine handling process of some of the precautions, as well as tensile strength machine installation process need to pay attention to some of the problems.

Installation of the tension machine need to pay attention to the problem
1, should ensure that the installation floor of the tension machine for the flat cement floor or tile floor.
2, after the installation of the tension machine, a variety of accessories and random tools should be placed in separate categories, in order to use, find convenient.
3, should ensure that the working environment of the tensile strength machine is clean and dry, so as to avoid premature damage to parts and accidents.

4, before the tensile testing machine is energized, to ensure that the supply voltage in line with the provisions of the tensile machine into the voltage value, equipped with three-wire power plug tensile machine, must be inserted into the socket with a protective grounding power supply to ensure safety.
5, tensile testing machine must pay attention to adjust the travel limit switch, can play a protective sensor collision.

6, tensile strength machine on the temperature and humidity have strict requirements, should ensure that the installation environment room temperature 10 ~ 35 ℃, relative humidity <80%RH Packaging installation of the ground without vibration, no corrosive media and strong electromagnetic field interference.

Tensile testing machine handling precautions

1, in the tensile strength machine before handling, the staff should ensure that the relevant objects are complete. Installation of the packing box in the random documents in the "packing list" carefully count the objects, check the random documents, tools, instruments accessories are complete, such as the discovery of leakage should be made up in a timely manner.
2, to ensure that the tensile testing machine internal sensors and other precision devices, avoid collision in the handling process, and do not place the tensile machine lying down.
3, tensile strength machine host outer cover plate is aluminum profile, can not bear the weight, to ensure that the transportation process, the tensile strength machine is not pressed by heavy objects.
4, when erecting the tensile testing machine, should first remove the foot plate on the ring screws, and pay attention to the center of gravity of the host changes to prevent tipping.
5, long-distance transportation should be waterproof and moisture-proof packaging, should be stored in a waterproof and moisture-proof environment.

What are the uses of tensile testing machines in industry?
With the continuous development and progress of science and technology and the continuous development of various industries, the tensile testing machine equipment put forward new requirements, the tensile testing machine in various industries play an increasingly large role. Tensile testing machine competition is becoming increasingly fierce, and a high degree of automation, intelligent, multi-functional, high efficiency, low consumption of tensile testing machine equipment is increasingly favored by the industry. The degree of automation of the process is becoming higher and higher. Nowadays, Farrer Instruments' tensile testing machines make extensive use of computerized design and mechatronic control to improve the flexibility and agility of the equipment.

Tensile testing machine in the industry is mainly applied to metal and non-metallic materials testing, such as rubber, plastic, wire and cable, fiber optic cable, seat belts, safety belts, leather belt composite materials, plastic profiles, waterproof coil, steel pipe, copper, profiles, spring steel, bearing steel, stainless steel (and other high hardness steel), castings, steel plates, steel strips, non-ferrous metals, metal wires, such as tension, compression, bending, shearing, peeling, tearing, two-point extension (need to be equipped with another extensometer) and many other tests. Tensile, compression, bending, shear, peeling, tearing, two-point extension (need to be equipped with a separate extensometer) and other tests. Tensile testing machine in the industry what are the uses of Shanghai Farrer Instruments production of tensile testing machine is widely used in measuring quality inspection; rubber and plastic; metallurgy and steel; machinery manufacturing; electronic appliances; automotive production; textile and chemical fibers; wire and cable; packaging materials and food; instruments and meters; medical equipment; civil nuclear energy; civil aviation; colleges and universities; scientific research institutes; commodity inspection and arbitration, technical supervision departments; building materials and ceramics; Petrochemical industry; other industries. What are the uses of tensile testing machine in industry common test items: (common display value and calculated value)
●Tensile stress ●Tensile strength
●Tearing strength ●Tearing elongation
●Constantaneous elongation at constant stress
●Calibrated stress value ●Tear strength
●Force at any point ●Elongation at any point
●Extraction force ●Bonding force and taking peak calculated value

       What is a testing machine? What products does it include?
For materials, parts, components for mechanical properties and process performance testing machine instruments and equipment for material testing machine.
The tester includes:Material testing machine, non-metallic material testing machineThe company offers a wide range of testing equipment and instruments, including process testing machines, force (torque) measuring machines, balancing machines, vibration tables, non-destructive testing instruments, functional accessories for testing machines, and testing equipment and instruments related to the specialty of testing machines.
 * Metal material testing machine:
　　Electronic testing machine, tensile testing machine, pressure testing machine, electro-hydraulic testing machine, hydraulic testing machine, electro-hydraulic servo testing machine, hydraulic tensioning machine (hydraulic jacks), torsion testing machine, creep testing machine, relaxation testing machine, pendulum impact testing machine, fatigue testing machine, high-frequency testing machine and so on;
　　Brinell hardness tester, Rockwell hardness tester, Vickers hardness tester, micro hardness tester, Brodwell multi-purpose hardness tester, Shaw hardness tester, Richter hardness tester, etc..
* Non-metallic material testing machine:
　　Rubber and Plastic Testing Machine, Constant Stress Cement Pressure Tester, Concrete Tester, Ceramic Tester, Wood Tester, Paper Tester, Leather Tester, Interfacial Tensile Tester, etc;
　　Shore hardness tester, inter-rubber hardness tester, etc.
＊ Force and deformation testing instruments:
　　Force transducers, standard force gauges, displacement transducers, extensometers, torque gauges, force standardizers, torque standardizers, etc.
* Process tester
　　Friction & Abrasion Tester, Spring Tester, Bending Tester, Cupping Tester, Wire Torsion Tester, etc.
* Dynamic test equipment:
　　Electrodynamic vibration table, hydraulic vibration table, mechanical vibration table, collision test bench, impact table, package drop test machine, package horizontal impact test machine, vehicle testing equipment, simulated automobile transportation test bench, etc.;
　　General-purpose horizontal balancing machine, general-purpose vertical balancing machine, soft bearing balancing machine, hard bearing balancing machine, high-speed balancing machine, on-site balancing instrument, etc.
* Non-destructive testing instruments:
　　Magnetic Particle Flaw Detector, Fluorescent Magnetic Particle Flaw Detector, X-ray Flaw Detector, γ-ray Flaw Detector, Ultrasonic Flaw Detector, Ultrasonic Detector, Eddy Current Flaw Detector, Acoustic Emission Flaw Detector, etc.
* Functional accessories for the test machine:
　　High-temperature furnace, low-temperature chamber, hydraulic chuck, fixture, etc.

durometer
Hardness conversion formula.
1. Shore hardness (HS) = Burr hardness (BHN) / 10 + 12
2. Shaw hardness (HS) = Rockwell hardness (HRC) + 15
3. Burr Hardness (BHN) = Rock Hardness (HV)
4. Rockwell Hardness (HRC) = Burr Hardness (BHN)/10-3
　
Hardness Measurement Range.
HS<100
HB<500
HRC<70
HV<1300

(80~88)HRA, (85~95)HRB, (20~70)HRC

Rockwell hardness in the HRA, HRB, HRC, etc. in the A, B, C for three different standards, known as scale A, scale B, scale C.
The Rockwell hardness test is one of several common indentation hardness tests in use today, and all three scales have an initial pressure of 98.07N (10kgf), with the hardness value calculated from the depth of the indentation. Scale A uses a conical diamond-shaped indenter, which is then pressurized with 588.4N (60kgf); Scale B uses a 1.588mm (1/16-inch) diameter steel ball as the indenter, which is then pressurized with 980.7N (100kgf); and Scale C uses the same conical diamond-shaped indenter as Scale A, but the pressurized force is 1471N (150kgf). Thus Scale B is suitable for relatively soft materials, while Scale C is suitable for harder materials.
Practice has proved that the genus material between the various hardness values, hardness value and strength value has an approximate corresponding relationship. Because the hardness value is determined by the beginning of plastic deformation resistance and continue plastic deformation resistance, the higher the strength of the material, the higher the plastic deformation resistance, the higher the hardness value. However, the conversion relationship of various materials is not consistent. The article "Hardness Comparison Table" on this site gives a table for the conversion of different hardness values of steel, please consult it.

Hardness expresses the ability of a material to resist a hard object pressed into its surface. It is one of the important performance indexes of genus materials. Generally the higher the hardness, the better the wear resistance. Commonly used hardness indicators are Brinell hardness, Rockwell hardness and Vickers hardness.
1. Brinell hardness (HB)
With a certain load (generally 3000kg) to a certain size (diameter is generally 10mm) of hardened steel ball pressed into the surface of the material, keep for a period of time, after de-loading, the load and its indentation area ratio, that is, the Brinell hardness value (HB), unit of kilograms of force/mm2 (N/mm2).
2. Rockwell hardness (HR)
When HB>450 or the specimen is too small, can not be used Brinell hardness test and instead of Rockwell hardness measurement. It is an angle of 120 ° of the corundum cone or diameter of 1.59, 3.18 mm steel ball, under a certain load pressed into the surface of the material to be measured, by the depth of the indentation to find out the hardness of the material. Depending on the hardness of the test material, it is expressed in three different scales:
HRA: This is the hardness obtained using a 60kg load and a diamond cone indenter, and is used for hard materials (e.g., hardened alloys, etc.).
HRB: The hardness obtained by using 100kg load and 1.58mm diameter hardened steel ball, used for materials with lower hardness (e.g. annealed steel, cast iron, etc.).
HRC: This is the hardness obtained using a 150kg load and a diamond cone indenter, and is used for very hard materials (e.g. hardened steels, etc.).
3 Vickers hardness (HV)
A load of 120kg or less and a diamond square cone indenter with an angle of 136° are pressed into the surface of the material, and the surface area of the indentation pit in the material is divided by the value of the load, which is the Vickers hardness HV value (kgf/mm2).

Maintenance and upkeep:
1, the test machine should be installed in a clean, dry environment without vibration sources and the presence of corrosive gases.
2, to often keep the equipment clean and hygienic + to prevent rust and corrosion.
3, each time after the test to do a cleaning and sanitation work.
4, regular inspection often keep the good condition of the test machine, to maintain the integrity of all parts of the equipment.
5, the test machine should be based on specific conditions for the replacement of hydraulic oil.
6, regular cycle calibration + to ensure that the display value error meets the requirements.
7, the test machine should be used in accordance with the requirements of the manual within the scope of use, and to do the correct operation, and in the test should pay attention to the specimen placed correctly do not eccentric loading.
8, the establishment of maintenance system to determine the person responsible for and have the use of maintenance records.

Today the dynamic mechanical properties of rubber are an important part of the study of rubber properties. Under certain conditions, rubber will show different states such as glassy state, rubbery state and viscous flow state. Rubber dynamic mechanical properties test is to study the rubber at different temperatures, under different force conditions, the mechanical properties of rubber show changes. Rubber dynamic mechanical properties test is generally divided into the basic test and dynamic mechanical test of rubber materials, rubber products, dynamic mechanical properties of the test two.

Dynamic mechanical properties of rubber materials

The basic mechanical properties test of rubber materials is mainly to detect the mechanical properties of materials in tensile, compression, shear and volume compression test test. Rubber material base test has a total of 8 kinds: uniaxial tensile test, uniaxial compression test, biaxial tensile test, biaxial compression test, plane tensile test, plane compression test, volumetric tensile test, volumetric compression test. The dynamic performance test methods of rubber materials mainly include free attenuation vibration test method; forced vibration test method; forced non-resonance test method; acoustic wave propagation test method. According to the deformation type classification, rubber material dynamic performance test method can be divided into tensile, compression, torsion, shear and bending, etc., the type of test deformation will determine the type of modulus obtained from the test results.

Dynamic mechanical properties test of rubber products

The dynamic mechanical performance experiments of rubber products include: static mechanical performance experiments, dynamic performance experiments, and fatigue performance experiments. Among them, because the rubber material contains internal friction independent of the speed of movement, and the friction parameters related to it need to be measured in the static mechanical performance experiment, so it is also necessary to carry out the static mechanical performance experiment. Dynamic mechanical performance experiments can be obtained through the dynamic stiffness, dynamic damping and dynamic loss angle tangent of the rubber product. The fatigue experiment reflects the service life of rubber products that can be achieved under the alternating load, and studies the effects of mechanical load, ambient temperature, formulation and so on on the use of material properties.

Rubber dynamic mechanical properties test, can help us better understand the performance of rubber materials and products. At low temperatures, the structural modulus of the rubber molecular chain, whether it conforms to the description of Hooke's law under the receipt of external forces. At medium and high temperatures, the molecular chain degrees of freedom change, the elastic deformation ability of rubber after withstanding the force; at high temperatures leading to irreversible viscous six states of analysis, as well as different frequencies and time, low frequency, high frequency under the soft and high elasticity and rigid hardness of the performance of the performance.

Gas cylinders in the laboratory is mainly used as gas chromatography and atomic absorption analysis to provide carrier gas, gas and combustion gas source. In order to ensure the safe use of pressure cylinders, to protect the safety of staff and national property, inspectors must master the knowledge of the safe use of gas cylinders. Gas cylinder storage and safe use requirements are as follows.

(1) Cylinders must be stored in a cool, dry room away from heat sources, and open flames should be strictly prohibited to prevent exposure to the sun.

(2) When using gas cylinders, place them in an upright and fixed position to prevent tipping.

(3) Handling cylinders should be carried gently and put down gently to prevent dropping, knocking, rolling or violent vibration. Wear a safety cap on the mouth of the cylinder before handling to prevent accidents from accidentally breaking the mouth of the cylinder.

(4) Cylinders during use should be regularly inspected, and unqualified cylinders should be scrapped or downgraded for use.

(5) The pressure reducing valve of the gas cylinder should be specialized, and the screw button should be tightened when installing (it should be screwed into 7 turns of threads, commonly known as eating seven teeth), and there should be no air leakage. When opening a high-pressure gas cylinder, the operator should stand on the side of the cylinder outlet, move slowly to reduce air friction, to prevent static electricity.

(6) Gas cylinders that are prone to polymerization reactions, such as acetylene and ethylene, should be used within the storage period.

(7) Oxygen cylinders and their special tools are strictly prohibited from contacting with oily substances, and the operator cannot wear work clothes and gloves stained with grease or oil for work.

(8) The distance between cylinders containing flammable gases such as hydrogen cylinders and open flames should not be less than 10m.

(9) The gas in the bottle shall not be completely exhausted, and the residual pressure of 0.2~1MPa shall be maintained in general (for the needs of gas filling unit for testing and sampling and preventing other gases from backing up).

(10) Gas cylinders should be inspected for safety conditions before use, paying attention to the color of the paint on the cylinders and the markings, and confirming the gas contained.

(11) It is strictly prohibited to weld arcs on gas cylinders, and welding repairs shall not be carried out.

(12) Users of liquefied petroleum gas cylinders shall not refill the liquefied petroleum gas in the cylinders to other cylinders or dispose of the residual liquid in the cylinders by themselves.

(13) Cylinders must be used exclusively for special purposes and must not be modified without authorization, so as to avoid chemical reactions and explosions caused by mixing gases of conflicting natures.

(14) The pressure reducing valve used for gas cylinders should be specialized, the pressure reducing valve used for oxygen cylinders can be used on nitrogen or air cylinders, but the pressure reducing valve used for nitrogen cylinders, such as used on oxygen cylinders, must be fully washed with grease and then used.

Rubber is a highly elastic polymer material with reversible deformation, elastic at room temperature, capable of large deformations under very small external forces, and capable of returning to its original state after the removal of external forces. Rubber is a completely amorphous polymer with a low glass transition temperature (T g) and a molecular weight that is often very large, greater than several hundred thousand.

General rubber performance testing can be done in accordance with ISO, ASTM, DIN, GB, HB and other standards, to carry out the physical and chemical properties of rubber, vulcanized rubber, rubber products and rubber auxiliary compatibility of the physical and mechanical properties of the test. Rubber performance testing mainly includes the following aspects:

Physical and Mechanical Properties: Density Hardness Surface Resistivity Dielectric Properties Tensile Properties Impact Properties Tearing Properties Compression Properties Bonding Strength Abrasion Resistance Low Temperature Properties Rebound Properties

Aging performance: heat aging Ozone aging UV aging Salt spray aging Xenon aging Carbon arc lamp aging Halogen lamp aging

Liquid resistance: lubricants, gasoline, motor oil, acids, alkalis, organic solvents, water.

Combustion Properties:Vertical Combustion Alcohol Blowtorch Combustion Alleyway Propane Combustion Smoke Density Burning Rate Effective Calorific Value of Combustion Total Smoke Release.

The performance of rubber can be divided into two categories, namely, structural performance and functional properties, structural performance refers to high elasticity and strength and other mechanical properties; functional properties refers to the physical and chemical properties of rubber, such as media resistance, electrical insulation, chemical corrosion resistance. In rubber products, some to use the former type of performance-based, such as shock absorption products, sealing products; some use the latter type of performance-based, such as water seals (water resistance) and cable sheaths (electrical insulation) and so on. But in all the properties, structural properties, that is, the mechanical properties of the most important. Because it is the basis of all properties.

The process used to determine the number of fatigue stress or strain cycles in a material or structure. Fatigue is the process of localized, permanent damage increment that occurs at a point in a material under cyclic loading conditions. After a sufficient number of stress or strain cycles, the accumulation of damage can cause the material to crack, or the crack can extend further to complete fracture. Visible cracks or complete fracture are collectively referred to as fatigue damage.

Fatigue tests are divided into two categories according to the number of damage cycles:

(1) High-cycle fatigue (high-cycle fatigue) tests, for which a low level of cyclic stress is applied;

(2) low cycle fatigue (low cycle fatigue) test, when the cyclic stress often exceeds the yield limit of the material, so by controlling the strain to implement the loading. According to the nature of the material is divided into metal fatigue test and non-metal fatigue test;

According to the working environment including high temperature fatigue test, thermal fatigue (caused by cyclic thermal stress) test, corrosion fatigue test, micromotion friction fatigue test, acoustic fatigue (caused by noise excitation) test, impact fatigue test, contact fatigue test and so on.

First of all, the error is an objective physical quantity with a certain value of the measured component, called the true value, and the difference between the measured value and the true value is called the error. According to the cause of the error, it is usually divided into two categories, namely, systematic error and chance error.

The main source of error, systematic error is caused by a fixed reason for the error, in the process of measurement according to a certain law to repeat, there is a certain degree of squareness, that is, the determination of the value is always high or always low, the size of this error is measurable, so it is also known as "measurable error". It comes from the analytical method error, instrument error, reagent error and subjective error, such as analysts master operating procedures and operating conditions and other factors.

Accidental error is due to some accidental external causes of error, the cause is often not fixed, unknown, and the size of the size, or positive or negative, the size is not measurable, the source of such errors are often difficult to detect a moment, may be due to the environment (air pressure, temperature, humidity) and other accidental fluctuations or instrument performance, analysts are inconsistent in the treatment of the various specimens produced.

Secondly, the size of the error is directly related to the precision and accuracy of the analyzed results. Measures to minimize errors are as follows:

1. Correctly selected sample size

The amount of sample volume has a great deal to do with the accuracy of the analytical results. In macronutrient analysis, too much or too little titer or weight directly affects accuracy. In colorimetric analysis, the relationship between content and absorbance is often linear only within a certain range. This requires that the measurement be read within this range to improve accuracy. This can be achieved by increasing or decreasing the sample size or changing the dilution.

2. Increase the number of parallel measurements

Reduce the chance error the more measurements, the average value will be closer to the real value, the chance error can also be offset, so the analysis results will be more reliable. General requirements for each sample should not be less than two measurements, such as more accurate measurement, the number of analyses should be more.

3. Controlled tests

A control test is an effective method for checking systematic errors. In the control test, often with known results of the specimen and the test sample together in exactly the same steps, or by different units, different people to carry out measurements, and finally the results will be compared. This can offset many of the errors caused by unknown factors.

4. Blank test

A blank test is performed while the sample measurement process is being carried out, using exactly the same operating method and reagents, except that the substance to be measured is not added. By deducting the blank value from the measured value, systematic errors due to factors such as interference from impurities in the reagents can be canceled out.

5. Calibration instruments and calibration solutions

Various measuring and testing instruments, such as laboratory electronic balances, rotameters, spectrophotometers, as well as pipettes, burettes, volumetric flasks, etc., must be calibrated for accurate analysis and used in calculations with more positive values. Various standard solutions (especially reagents that are susceptible to change) should be calibrated regularly as required to ensure the concentration and quality of the standard solution.

6. Strictly follow the operating procedures

The technical conditions specified in the analytical method are to be strictly observed. Analytical methods prescribed by the State or competent authorities should not be altered without the consent of the relevant authorities.

Fatigue test is a kind of reliability test, which utilizes rubber, plastic specimens or simulated parts in various environments, subjected to alternating loads to determine its fatigue performance criteria, and study the fracture process of the test.

Test Stress

Test stress (strain) and life (cycle times): high cycle fatigue low cycle fatigue

Room temperature fatigue Low temperature fatigue High temperature fatigue Heat fatigue

test environment

Corrosion fatigue Contact fatigue Micromotion wear fatigue

Loading method

tensile fatigue

Bending fatigue: rotational bending fatigue, three-point bending fatigue, four-point bending fatigue, cantilever bending fatigue

twisting fatigue

Complex Stress Fatigue

Fatigue test procedure

1. Receive the specimens required for the test and measure the original dimensions of the specimens with vernier calipers. Specimens with machining defects on the surface shall not be used.

2. Turn on the machine and set the test parameters.

3. Mounting the specimen. Keep the specimen in good coaxiality with the test machine spindle.

4. Static test. Take one of the qualified specimens, first tensile measurement of its σb. The purpose of the static test on the one hand to check whether the strength of the material in line with the requirements of heat treatment, on the other hand, can be based on this to determine the level of stress at all levels.

5. Set the specific parameters of the fatigue test and carry out the test. The first specimen has a maximum stress of about (0.6 to 0.7) σb and fails after N1 cycles. Following take another specimen so that its maximum stress σ2 = (0.40~0.45) σb, if its fatigue life N 107 under σ2. so that the endurance limit σ-1 of the material is between σ1 and σ2. Between σ1 and σ2 insert 4 to 5 equal differential stress levels, which are σ3 ﹑ σ4 ﹑ σ5 ﹑ σ6, step by step decreasing for the experiment, the corresponding life of N3 ﹑ N4 ﹑ N5 ﹑ N6, respectively.

6. Observation and recording. Perform the test in steps from high to low stress levels. Record the number of cycles of fracture for each specimen while observing fracture locations and characteristics.

7. At the end of the experiment, remove the test piece. Clean up the experimental site and restore all mechanisms of the testing machine.

8. Perform relevant calculations based on the experimental records. Tabulate the experimental data obtained; then plot a smooth S-N curve with lgN as the horizontal coordinate and σmax as the vertical coordinate, and determine the approximate value of σ-1.

Detection Methods

Expansion rate test Determination of S-N curve Rotational bending method

Testing Instruments

Fatigue Testing Machine Mechanical Testing Machine Tensile Testing Machine Pressure Testing Machine Salt Spray Testing Machine

Environmental Testing Machine Constant Temperature and Humidity Tester Low Temperature Cold Resistance Testing Machine Salt Spray Tester

Rapid temperature change testThe main test products repeatedly withstand temperature extremes of endurance, the product used parts, materials in the temperature drastic changes may occur mechanical failure, cracking, seal damage, leakage and other phenomena. Drastic changes in temperature on the main impact of the equipment, so that the assembly of parts or welding points loose or off, so that the material itself cracking, electronic component performance changes; d. Seal failure caused by leakage and so on.

Rapid temperature change test applicable fields: Electronic and electrical engineering, automobile and motorcycle, aerospace, rubber, plastic, metal, ships and weapons, colleges and universities, scientific research units and other related products, parts and materials in the rapid temperature change test, test its various performance indicators.

Rapid temperature change testBased on criteria

GB/T 2423.34, IEC 60068-2-38, JB150.5, etc.

Properties that can be determined by the tensile test include:

Ultimate tensile strength

yield strength

malleable

elongation

Section shrinkage

modulus of elasticity

proportionality limit

elastic limit

resilience

Some values in a tensile test can be read directly from the meter. Others can only be quantified by analysis of the stress-strain diagrams produced during the test. The values of ductility can be obtained by comparing the pre-test and post-test measurements of the specimens. The percentage difference between them is the ductility

The value of the spread rate.

When performing a tensile test, one of the most important aspects of the test is the preparation of the tensile specimen. If this part of the test is not meticulously prepared, the validity of the test results will be greatly reduced. For example, a small imperfection in the surface finish can cause a significant reduction in the strength and ductility of the tensile specimen.

Sometimes a weld specimen is tensile tested simply to see if the weld behaves like the base metal. In this case, all we have to do is to cut the specimen (sometimes called a test strip) perpendicular to the longitudinal axis of the weld so that the weld is approximately in the middle of the specimen. The sides of the specimen are cut with a saw or flame, keeping the sides parallel, but no further surface preparation is required, including removal of the weld strength. However, the weld reinforcement is often smoothed.

This method is used for the evaluation of welding processes and the evaluation of welders' skills according to API 1104. According to this specification, a successful tensile test is one in which the specimen breaks at the base metal or at the weld seam where the tensile strength is above that of the base metal.

Tensile tests are required in most cases, but sometimes it is also necessary to test the actual strength and other properties of the metal, not just to see if the weld is as strong as the base metal. When these values are to be determined, the specimen must be prepared in such a way that it is close to the length of the specimen.

A reduced cross section is machined at the center of the degree.

The main reason for machining to a reduced cross section is to lock the fracture location. Otherwise the fracture may occur preferentially near the clamping end, making subsequent measurements difficult. In addition, the reduced-section specimen results in a very uniform stress increase across the entire cross-section. In order to obtain valid results, the shrinkage

The cross section must have the following three properties:

(1) The entire length of the reduced section must be a uniform cross-section.

(2) The cross-section should be a figure that can be easily measured and the cross-sectional area can be calculated.

(3) The surface of the reduced section shall be free from surface irregularities, particularly those perpendicular to the longitudinal axis of the specimen.

For these reasons, and because of the need for machining to prepare the specimens, the two most common cross-sections used in tensile specimens are circles and rectangles. Both are easy to prepare and measure. If a tensile test is to be performed, the weld inspector must be able to calculate the actual cross-section of the reduced cross-section of the tensile specimen.

Accumulation.

High and low temperature test chamber can simulate high temperature and high humidity, high temperature and low humidity, low temperature and low humidity and other different environmental test conditions, suitable for testing the heat resistance of the material, dry resistance, humidity and cold resistance, in order to determine the aging resistance of the product and resistance to the performance of special environments;

High and low temperature chamber is widely used in electronics, communications, chemical, plastic, rubber and other manufacturing industries.

1. Safety and reliability of test equipment

Environmental testing, especially reliability testing, the test cycle is long, the test object is sometimes high value products, xenon lamp weatherproof test chamber test process, the test personnel often have to operate around the scene to check or test work, the

Therefore, the requirements of environmental test equipment must have safe operation, easy to operate, reliable, long working life and other characteristics of the xenon lamp climatic test chamber to ensure that the test itself is carried out properly.

Test equipment, a variety of protection, alarm measures and safety interlocking devices should be perfect and reliable to ensure the safety and reliability of the test personnel, the product under test and the test equipment itself xenon lamp weatherproof test chamber.

2. Measurability and control of environmental condition parameters

Any environmental test equipment to provide environmental conditions must be observable and controllable, UV aging tester which is not only to make the environmental parameters are limited to a certain tolerance range, to ensure that

Proof of the reproducibility of test conditions and repeatability requirements, but also from the safety of the product test is also necessary, UV aging test chamber in order to prevent environmental conditions out of control leading to the damage of the product under test, bringing unnecessary losses.

Various current test specifications broadly require that the accuracy of parameter testing should not be less than one-third of the error allowed by the test conditions.

3. Reproducibility of environmental conditions

In the test chamber complete and reproduce the environmental conditions that exist in nature is unattainable. Ultraviolet weathering test chamber, however, within certain tolerances, people can be completely correct and approximate simulation of engineering products in the use, storage, transportation and other processes in the external environmental conditions.

Ultraviolet light from sunlight is a major factor in the destruction of the durability of most materials. In UV weathering tests, fluorescent UV from UV lamps etc. reproduce the effects of sunlight, and condensation and water spray systems reproduce the effects of rain and dew.

UV Aging Test Principle

UV aging tests are applicable to the aging of non-metallic materials against sunlight and artificial light sources. UV aging tests simulate the damaging effects of sunlight, humidity, and temperature on materials; material aging includes fading, loss of light, loss of strength, cracking, peeling, chalking, and oxidation. By simulating sunlight, condensation, and mimicking natural humidity, UV weathering testers can reproduce damage that may occur outdoors over months or years by testing specimens for hours or even days in a simulated environment. 

UV Aging Test Scope

Non-metallic materials, organic materials (e.g. paints, lacquers, dyes, fabrics, printing and packaging, adhesives, automotive and motorcycle industry parts, cosmetics, metals, electronics, electroplating, rubber, plastic and their products, etc.)

UV Aging Test Standard

GB/T 16585-1996 Artificial climate aging of vulcanized rubber (fluorescent ultraviolet lamp) test method

GB/T 14522-2008 Artificial Climate Aging Test Method for Plastic, Paint and Rubber Materials Fluorescent UV Lamps

ASTM D4329-2005 Standard for Fluorescent UV Exposure of Plastics

ASTM D4587-2011 Standard for Fluorescent Ultraviolet Condensation Exposure of Paints and Related Coatings