Quality & testing

UL Witnessed Test Data Program laboratory

STE joined the UL Witnessed Test Data Program (WTDP) in 2013–2014 for UL 1449 (varistors) and UL 60384-14 (safety capacitors), under laboratory no. 701335-001. Under this program, testing takes place at STE’s laboratory and is witnessed by UL staff.

The two Certificates of Achievement below record UL’s acceptance of test data for the named projects. They retain the standard editions, project numbers and test dates shown on the certificates.

CNAS-accredited testing center

The testing center of Guangdong Songtian Electronic Industrial Co., Ltd. is accredited by the China National Accreditation Service for Conformity Assessment (CNAS) to ISO/IEC 17025:2017 (CNAS-CL01), registration no. L24638. The certificate is valid from 19 March 2026 to 25 November 2031.

CNAS assesses laboratory competence against internationally recognized criteria. Its assessment covers personnel, equipment, environmental conditions, test methods, sample handling, quality management, measurement traceability and the accuracy of results.

The center supports testing of ceramic capacitors, film capacitors, varistors and thermistors for product development, incoming-material inspection, finished-product inspection and customer quality requirements.

CNAS participates in the ILAC and APAC mutual recognition arrangements. The accredited scope is defined in the annex to certificate CNAS L24638. Acceptance of a test report depends on its scope, the applicable arrangements and the recipient’s requirements.