What is product certification? Why is certification required for any product?
Certification for any product means qualification for the specific country's standards. Getting the appropriate certification is crucial for selling the Internet of Things (IoT) product commercially in any country. This plays a very important role during shipments of products as well.
Basically, any device that has a wireless component in it, needs to undergo certification. And merely using “certified” modules does not guarantee success. Failures can happen due to design issues in your PCB.
Country Wise Certification:
General Certification procedures:
Steps involved in CE certification:
- Understanding the country-specific technical requirements
This process involves a detailed understanding of the country-specific requirements about its applicable standards and a list of tests involved with its acceptance criteria.
2. Designing of the prototype
This step is very crucial as we have to choose the LTE modem based on the country-supported LTE bands as well as take care of the conducted and radiated harmonics of the product to qualify for the EMI/EMC & wireless tests.
3. Choosing the Testing Lab:
Choosing the lab by auditing their lab capabilities and support for getting a certificate from the government body.
Lab Accreditations details: A2LA, ILAC, NABL, TEC.
Standards followed in Lab: ANSI Standards, EN (European standards), WPC Gazette (GSR NO), TEC ER (essential requirements of products).
4. Perform the Pre-Compliance Tests
Pre-compliance testing is also called “Development Activity Testing”. Testing of the product in the Certified Lab with the country-specific test requirements helps to go for the Compliance Tests with good confidence.
List of Tests Involved in CE Compliance:
Wireless Lab:
Radio Spurious Emission( RSE)
RF Output power
EMC Lab:
Radiated Susceptibility
Radiated Emission
Electrostatic Discharge
Power frequency magnetic field.
Detailed Test Plan:
a) RSE Test:
The device under test (DUT) will be placed on the 360deg table and the substitution antenna will be placed near the DUT as shown below. The device will be connected to the spectrum analyzer which acts as a base station. The spectrum analyzer measures the harmonics and gives the waveforms.
Test Setup:
Sample Results:
b) RF Output Power:
In radio transmission, transmitter power output (TPO) is the actual amount of power (in watts) of radio frequency (RF) energy that a transmitter produces at its output. The spectrum analyzer is connected to the antenna port of the DUT as shown below.
Sample Results:
EMC Lab Tests:
a) Radiated Emission:
Test Set-up and Operation Modes
Principle of Configuration Selection Emission:
The equipment under test (EUT) was configured to measure its highest possible radiation level. The test modes were adapted accordingly in reference to the instructions for use. Immunity: The equipment under test (EUT) was configured to have its highest possible susceptibility against the tested phenomena. The test modes were adapted accordingly in reference to the instructions for use.
Operation Modes: The operation modes used for testing are:
a. Normal operation with idle mode
b. Normal operation with communication 4G LTE mode.
Compliance criteria as per EN IEC 61000–6–2:
Performance criterion A: The EUT shall continue to operate as intended during and after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer when the EUT is used as intended. If the performance level is not specified by the manufacturer, this may be derived from the product description and documentation and what the user may reasonably expect from the equipment if used as intended.
Performance criterion B: The EUT shall continue to operate as intended after the test. No degradation of performance or loss of function is allowed below a performance level specified by the manufacturer when the EUT is used as intended. The performance level may be replaced by a permissible loss of performance. However, during the test degradation of performance is allowed but no change of actual operating state or stored data is allowed.
Performance criterion C: Temporary loss of function is allowed during the test, provided the function is self-recoverable or can be restored by the operation of the controls.
Acceptable Compliance Criteria as per ETSI EN 301 489–1 & 52
For transient transmission phenomena:
Sample Radiated Emission results:
b) Radiated Susceptibility:
During the test, the power ON LED indication, 4G LTE communication & data transfer function of the device on the laptop will be monitored. Any data loss or degradation during and after the test will be considered a test failure. All the modem-supported frequencies will be passed on to the device in an anechoic chamber to check the immunity of the DUT.
Sample Results:
c) Power frequency magnetic field:
During the test, the power ON LED indication, 4G LTE communication & data transfer function of the device on the laptop will be monitored. Any data loss or degradation during and after the test will be considered a test failure.
DUT will be placed at the center and the magnetic fields will be passed from horizontal, vertical, and circular modes and observe the device behaviors before and after the test.
The EUT was placed inside the 3 dB test volume at the center of a square inductive coil connected to a test generator. The system was producing a power frequency magnetic field of the specified level. The test was performed for three orthogonal orientations of the inductive coil. Test Frequencies are 50hz & 60hz.
Test Set Up:
Sample Results:
d) Electrostatic Discharge (ESD) Test:
The EUT was placed on non-conductive support of a height 10 cm above the ground reference plane (GRP). Electrostatic discharges were applied using an ESD gun either directly (via indirect or air discharges). During the test, the power ON LED indication, 4G LTE communication & data transfer function of the device on the laptop will be monitored. Any data loss or degradation during and after the test will be considered a test failure.
Test Setup:
Sample Test Results:
Conclusion:
Once we get the successful test reports from all the above tests, we can apply for country-specific certification through the Lab (if a country certification is required). These were the steps we need to follow to get secured market access.
