Calibration

EMC

EMC test equipment calibration

Novel electric devices are becoming increasingly complex; on one hand their physical dimension generally decreases but at the same time their power (densities) increases; these devices often contain fast and powerful switching elements especially for power supply; devices usually contain analogue as well as digital circuits; clock frequency of digital circuits is increasing constantly; and last and not least the devices often contain electronic communication modules. These novel and complex electric devices on one hand cause disturbances by emitting electromagnetic field or by applying disturbances over cables (e.g., supply cord, communication cables). Furthermore, these devices are also sensitive to disturbances that are caused by other devices. To ensure that such devices live in the same electromagnetic environment without any disturbances and work properly, it is mandatory to perform EMC testing. The testing should be performed according to specific international standard in specialized EMC test laboratory to prove that devices operate correctly without excessive emissions and are protected from electromagnetic disturbances from the environment. During the EMC test a special EMC measuring/test equipment should be used which needs to be periodically calibrated.

Why to calibrate EMC equipment?

EMC product testing is performed by EMC equipment that measure electromagnetic disturbances or generate/simulate different electromagnetic phenomenon. Such equipment must be periodically calibrated to ensure that the generated or measured parameters are properly controlled and precisely defined as it is stated in international standards. Periodical calibrations therefore prove EMC equipment is suitable for EMC testing according to international EMC standards. Calibration also brings certainty to your EMC equipment to access EUT pass/fail criteria.

SIQ EMC calibration laboratory

SIQ is specialized for conducted EMC test equipment calibration. The calibration can be performed in SIQ laboratory or in your premises (on-site). On-site calibration is very convenient service if EMC equipment is very large or difficult to disconnect from the system e.g., RF Amplifiers, AC Sources and Digital Power Analyzers for Harmonics & Flicker testing etc. General calibration parameters for different EMC test equipment are listed in the table below. EMC test equipment calibration demands careful measurement configuration setups with many special equipment and adapters, which are also developed and fabricated within SIQ.

SIQ also offers customized calibration services for your EMC test application.

Calibration of test equipment at SIQ

Artificial mains network-AMN/Line impedance stabilization network - LISN

AMN/LISN calibration is performed according to CISPR 16-1-2, ISO 7637 or CISPR 25/ISO 11452-4. Standard calibration parameters are:

impedance (magnitude and phase)
Voltage Division Factor
insulation

SIQ also calibrates asymmetric (common mode) artificial networks (AANs), where main calibrated parameter is Longitudinal Conversion Loss (LCL). Calibration of 1 and 3 phase LISN connectors are also supported.

Surge Generator

Surge generator calibration is performed according to IEC 61000-4-5. Standard calibration parameters are:

open circuit peak voltage
duration and front time
short circuit peak current duration
front time

Calibration can be also provided for coupling and decoupling networks for different coupling impedances, symmetrical and unsymmetrical interconnection lines.

Burst Generator and Capacitive Clamp

Burst generator calibration is performed according to IEC 61000-4-4. Standard calibration parameters are:

open circuit output test voltage
burst duration
rise-time
repetition frequency, burst period
burst period

Calibration is performed into 50 Ω and into 1000 Ω load.

Capacitive Clamp is calibrated using burst generator, where transient signal is introduced to capacitive clamp and measured with transducer plate terminated with 50 Ω load. Calibration parameters are:

rise time
pulse width and
peak voltage

Voltage Dips, Short Interruptions and Voltage Variation Generators

Calibration of voltage dips, short interruptions and voltage variation generators is performed according to IEC 61000-4-11 with parameters:

output voltage
overshoot
undershoot
transition time/rise time and
phase angle accuracy

Calibration is performed at 90° and 270° at 50 Hz or 60 Hz. Voltage dip transformer to generate 80%, 70% and 40% dip should be applied to generator in case it is not integrated into test equipment.

Voltage Dips, Short Interruptions and Voltage Variation Generators

Ring Wave immunity test generator

Ring wave generator calibration is performed according to EN 61000-4-12, which requires calibration of the following parameters:

voltage rise time
current rise time
voltage oscillation frequency
decaying
repetition rate
output impedance
open-circuit peak voltage
short-circuit peak current and
phase shifting

Damped oscillatory wave immunity test generator

Damped oscillatory test generator calibration is performed according to EN 61000-4-18, which requires calibration of the following parameters:

voltage rise time
oscillation frequency
repetition rate
decaying
burst duration
open-circuit voltage and
short-circuit current

Damped Oscillatory Wave Immunity Test Generator

Electrostatic discharge immunity test simulator, ESD simulators

ESD simulator calibration can be calibrated according to IEC 61000-4-2 and ISO 10605. SIQ can calibrate the following RC modules:

150 pF/330 Ω
330 pF/330 Ω
150 pF/2000 Ω and
330 pF/2000 Ω

Standards require calibration of the following parameters of ESD impulse:

peak current
current at 30 ns, 65 ns, 180 ns, 400 ns, 60 ns, 130 ns, 360 ns and 800 ns
rise time and
open circuit voltage

Calibration can be performed up to 30 kV.

SIQ can also calibrate ESD target, which is used for ESD simulator calibration. Calibration is in line with IEC 61000-4-2, which requires calibration of the following parameters:

transfer impedance
input resistance
attenuation
reflection

Current Probes

Current probe calibration is performed according to CISPR 16-1-2 in the sense of transfer impedance. Measurements are made on special calibration JIG, which enables calibration up to 500 MHz. We also calibrate BCI Probes (Bulk Current Injection probes), which are used in ISO 11452-4, Mil -STD-461, RTCA/DO-160 and EN/IEC 61000-4-6. Calibration is performed on special BCI jig, which enables transfer impedance calibration up to 1 GHz.

Low frequency transfer impedance is calibrated by injecting direct current into current probe using High Precision Multi-Product Calibrator as Fluke 5500A.

Absorbing Clamp CISPR 16-1-3

Absorbing clamp calibration is performed according to CISPR 16-1-3 and can be calibrated with the original and the JIG method. The most prominent parameter of absorbing clamp is CF (clamp factor) which is used to calculate a disturbance power on EUT line by measuring output voltage on measuring receiver on 50 Ω system. Additional parameters to describe an absorbing clamp is decoupling factor for the broadband absorber DF and a decoupling factor for the current transformer DR.

Coupling Decoupling Networks, CDN

CDN calibration is performed according to IEC 61000-4-6 and CISPR 15. Calibration points include measurements of:

common mode impedance on EUT side with AUX shorted and open, respectively.
additionally, we calibrate voltage division factor according to CISPR 15.

Calibration can be performed on different types of connectors e.g., 1-phase, 3 phase, USB, UTP unshielded, UTP shielded, telephone RJ11 etc.

Injection Clamp

Injection clamp calibration is performed according to IEC 61000-4-6. Calibration points include measurements of:

impedance on EUT side
decoupling factor between EUT and AE and
coupling factor between injection input connector and EUT

Impedance is calibrated using ABCD matrix generation and special renormalization technique, which analytically removes errors introduced by applied connectors. This also enables traceability of calibration to the SI unit definition.

EMI Receivers

EMI receiver calibration is performed according to CISPR 16-1-1, which requires calibration of the following parameters:

quasi-peak
peak
average and
CRMS detectors
selectivity

Calibration is performed for frequency bands A, B, C, D and E.

Harmonic Current Emission analyzer

Current harmonics analyzer calibration is performed according to EN IEC 61000-3-2. Calibration can be performed for 50 Hz and 60 Hz system for Class A, B, C and D. Additionally we can calibrate:

test voltage
test current
test frequency and
power factor

Flicker Emission analyzer

Flicker analyzer calibration is performed according to IEC 61000-3-3. Calibration can be realized for 50 Hz and 60 Hz system. Flicker is calibrated using reference power standard that generates different combinations of flicker parameters so that PST is always 1.

Flicker impedance (resistance and reactance) is measured for each line separately using reference LCR meter with HI power option integrated.

Common Mode Absorbing Device - CMAD

CMAD calibration is performed according to CISPR 16-1-4, which requires calibration of:

S11 and
S21

Measurements are performed on specially designed calibration fixture – JIG. Calibration procedure uses ABCD matrix to transform measured S-parameters to correct calibration JIG influence.

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