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UL Laboratory

What's UL?

As a global company with more thatn 120 years of expertise, Underwriter Laboraroies Inc., (UL) is the leading insititution of safety testing and recognition in the world. Since it's establishment, UL make a great contribution to helping companies demostrate safety, confirm compliance, deliver quality and performance, enhance sustainability and protect brand reputation. For now, UL is one of the most trustworthy institute of safety evaluation for manufacturer, and becoming the symbol of safety.

What's the significance of UL approval lab?

Since 2013, UL launched Data Acceptance Program (DAP) and started to approve the test data generated from enterprise. DAP not only provide great convenience for enterprise, but also shows most trust to the quality and safety for products that came from the enterprise has joined this program.
STE's UL Laboratory was identified by UL in 2013 and 2014, become the UL1449 (Varistor) and UL60384-14 (Safety Certified Capacitors) Withness Testing Data Program (WTDP). The Laboratory number is 701335-001.

What STE can do?

STE's Lab owns advanced test equipment which can offer professional and precise test data for electronic components, including weldability, soldering heat resistance, moisture load, steady heat, durability, rapid changes in temperature, flame resistance, pyrophoricity, etc.

Test Item

Safety Certified Capacitor





Metal Oxide Varistor



Class X2 

Class Y1 

Class Y2




Dissipation Factor


Withstand Voltage


Insulation Resistance


Impulse Voltage


Charge-Discharge Test


Varistor Voltage


DC Leakage Current


Clamping Voltage


Impulse Current


Maximum Peak Current


Surge Test


Nominal Discharge Test




Soldering Heat Resistance




Ripple Current Test




Durability on Continuous CurrentCondition


Durability on maximum  circular current



Tensile Strength


Flexural Strength



Damp Heat (Steady State)


Moisture Load


High Temperature Storage


Low Temperature Storage


Temperature Characteristics


Temperature Coefficient


Rapid Change of Temperature


Flame Resistance Test


Pyrophoricity Test



RoHS Test


Halogen Test