Calibration Services

Electrostatic Discharge (ESD) generators are used in immunity test of electromagnetic compatibility. SCL has set up calibration facilities for ESD generators in accordance with IEC 61000-4-2 Edition 2.0 (2008-12).

The following parameters of an ESD generator can be calibrated:

• Output voltage
• First peak current of discharge
• Rise time
• Current at 30 ns
• Current at 60 ns

 

Electrical Fast Transient/ Burst (EFT/B) generators are used in immunity test of electromagnetic compatibility.

The Standards and Calibration Laboratory has set up calibration facilities for EFT/B generators in accordance with IEC61000-4-4: 2012. This service has been accredited by HOKLAS for peak voltages up to 2.4 kV into 50 Ω load and 4.6 kV into 1 kΩ load respectively.

 

Surges are transient wave of voltage, current or power which rise rapidly followed by slower decline.

Surges are created by switching events and insulation faults in AC power distribution networks, lightning and others. Surges are high voltages. They contain significant amount of energy that may cause damages to the electronic and electrical devices.

IEC 61000-4-5 is the standard for surge immunity testing for electrical and electronic equipment. Surge Generators (Combination Wave Generators) are used in immunity test of electromagnetic compatibility. Surge Generators (Combination Wave Generators) generate and simulate the switching and lightning transients so as to evaluate the performance of the equipment under high-energy disturbances on the power and interconnect lines.

SCL has set up calibration facilities for surge voltage and current outputs of Surge Generators (Combination Wave Generators) in accordance with IEC61000-4-5:2014 standard. The following two types of surge generators can be calibrated:

• 1.2/50 µs (voltage surge) 8/20 µs (current surge).
• 10/700 µs (voltage surge) 5/320 µs (current surge).

 

The parameters that could be calibrated are:

• Front time
• Time to half value
• Voltage surge peak
• Current surge peak

 

Normally the Surge Generator under test is calibrated under voltage settings of 0.5 kV, 1.0 kV, 2.0 kV and 4.0 kV for positive and negative polarity. The maximum voltage setting that SCL can measure is 7.4 kV.

 

The operation of electrical and electronic equipment may be affected by disturbances in the supply network, such as voltage dips and short interruptions.

A voltage dip is a sudden reduction of the supply voltage below a certain voltage level (the dip threshold, the common values are 40%, 70% and 80% of the rated voltage) followed by recovery after a short time interval. A short interruption is a sudden reduction of the supply voltage on all phases below a certain voltage level (the interruption threshold, a common value is 0% of the rated voltage) followed by restoration after a short interval.

Voltage dips and short interruptions are usually caused by faults in the electricity supply network such as presence of short circuit or by sudden large variation in electric loading.

The International Standard IEC 61000-4-11 of electromagnetic compatibility is the standard for voltage dips and short interruptions testing for electrical and electronic equipment. A voltage dips and short interruptions generator is used to generate and simulate the voltage dips and short interruptions switching as closely as possible for evaluating the performance of the equipment.

SCL has set up calibration facilities for voltage dips and short interruptions generator in accordance with IEC 61000-4-11: 2004 + A1: 2017. The parameters that could be calibrated are:

• Ratios of the residual voltages to the rated voltage
• The rise time, fall time, overshoot and undershoot of the switching waveform
• The accuracy of the phase angle at switching