1. Should consider the tension range (max tebsile strength) of test material . The difference for the tension range, will determines the sensor, determines the structure of tensile testing machine, but this has little effect on the prices (except for door type). For general flexible packaging manufacturer, the max tensiion force of 200 Newton should be enough. Therefore it should use  the single arm type. ordinary, the tension force below 5KN use single arm type, the max force more than 5KN should door type, we usually call single arm type as tensile strength tester, the door type as universal testing machine. Flexible packaging manufacturers basically only need single arm type.

2. Should Consider the travel distance, our company usually call the travel distance is the distance between upper grip and lower (Some companies call  the travel distance is the max distance, it is the distance between upper grip and lower+the two grips' height). The different deformation of the material need different travel distance. If the deformation of material 600mm, should consider 750mm-800mm travel distance, because test different material, should be according to different standard, different standard need different gauge length .

 
3. The control method, it have LCD display and computerized control. The LCD display meaning use control panel (microcomputer) to control the machine, it have a better price, but the function and ourput results is not as strong as computerized, usually, we use LCD display model to get some basic parameters, such as tensile strength, peak value, elongation, elongation rate, this results can be output with thermal printer. Computerized type is using computer to control the machine, it have a stronger analysis function, usually can get the all results that customers want, such as tensile strength, peak value, elongation, elongtion rate, yield point, modulus........all results and test curves can be output to word, excel, user can edit it easily, some LCD display model can display the test curve, strictly speaking, the curve displayed by control panel do not have any meaning for detail analysis, because the mircompueter only can collect few test points, but computerized model can collect much more, in this state, if you want accurate test curves, should chose computerized model. The resolution of LCD display model is 1/100000, but the resolution of computerized model usually is more than 1/300000 or more. 

4. There are main four parts the user should consider specially, 1. Load sensor, it is mainly for force measurement, it have chinese brand or imported brand.  2. Photoelectric encoder, it is mainly for deformation measurement, for some material, if the user want to get a accuracy deformation, should chose extensometer for measure the deformation. 3. Some use stepper motor and drive system, it can reduce the cost, but the working is as good as servo motor and servo system, most company use servo motor and servo system nowadays, it also have chinese brand and imported brand.  4. The screws, all use ball screw nowadays, different ball screws also have different precision, there is another important factor is assembly, good company have professional and experience workers can assemble the whole machines perfectly.

5. For the speed, LCD display model's speed usually is 0.1-500mm/min, Computerized model usually is 0.01-500mm/min, some can be 0.001mm-500mm or better.

6.  Measurement accuracy:  including force measurement accuracy, speed, accuracy, and deformation precision, displacement accuracy. These highest precision value can be plus or minus 0.5. But for the average factory to achieve 1% accuracy is sufficient