JJG (Light Industry) 50.2-2000 "Corrugated Cardboard thickness tester verification code" specifies the verification and use requirements of corrugated Cardboard thickness testers with a range of not more than 20mm. The code applies to various instruments for corrugated fibreboard thickness measurement, covering manual and electric, mechanical and electronic tile thickness testers. The code specifies in detail the thickness indication Precision, Zero Stability, Appearance Requirements and the performance standards of the measurement head. Verification includes strict inspection of the instrument's Appearance, Indicator, Measurement Head and Contact Pressure to ensure the measurement accuracy and Stability of the instrument. The verification period is generally one year.