The core principle for selecting the range of an electronic universal tensile machine isMatch the maximum testing force of the sample and reserve reasonable redundancyTo avoid insufficient accuracy caused by excessive range or equipment overload caused by insufficient range, the specific steps and methods are as follows:

Core selection logic

First calculate“Maximum testing force of the sample”By calculating the tensile strength of the material and the cross-sectional area of the specimen, the formula is' maximum test force '（kN）=Material tensile strength（MPa）×Sample cross-sectional area（mm²）÷ 1000.

reserve20%~30%Redundancy: Final selection range=Maximum testing force×（1.2~1.3）Not only does it avoid overloading and damage to equipment, but it also ensures the accuracy of measuring small force values.

priority selection“Range coverage test sample testing force5%~100%”Model: Exceeding this range will result in insufficient force resolution and increased data error.

Specific calculation and selection steps

Determine key parameters

Check the tensile strength of materials such as copper200~600MPaSteel400~1000MPaTextile products10~50MPa.

Confirm the cross-sectional area of the sample: Prepare the sample according to the standard (such as the width of the gauge section of the metal sheet)×Thickness, the circular area of the yarn is calculated based on its diameter.

Calculate the maximum testing force

Example 1：1mmthick×10mmWide steel plate (tensile strength)600MPa）, cross-sectional area= 10mm²Maximum testing force= 600×10÷1000=6kN, Select Range= 6×1.3≈7.8kN, choose10kNmodel.

Example 2: Diameter5mmCopper wire (tensile strength)500MPa）, cross-sectional area≈19.6mm²Maximum testing force= 500×19.6÷1000=9.8kN, Select Range= 9.8×1.2≈11.8kN, choose20kNmodel.

Correction of special circumstances

Multi material testing: according to“Material with maximum testing force”Selection, taking into account the testing force of other materials within the range5%~100%Inside.

Impact materials: brittle materials (such as ceramics) have sudden changes in fracture force, and redundancy can be increased to30%~50%.

Recommended reference for different material ranges

Thin material/Soft materials (textiles, films, tapes):1~50kN(Mainly single column type).

Conventional metals/Plastic (copper strip, aluminum profile, engineering plastic):50~200kN(Double column type).

Thick sheet metal/Pipe materials (steel plate, seamless steel pipe):200~600kN(Double column type).

High strength thick materials (heavy-duty steel plates, alloy components):600~1000kN(Hydraulic driven double column)/Horizontal).