Because of the huge market size, selling electronic products in Europe is an enticing venture for many U.S. companies. But the venture has become challenging with the recent requirement to demonstrate compliance to today’s immunity testing standards.
These new immunity standards also add to your equipment needs. For example, the standards changed from the familiar IEC 801-3 radiated immunity standard to IEC 1000-4-3, reflecting a change from a specification for process-control equipment to one encompassing all electrical and electronic equipment.
Test-frequency modification is one of the significant differences in the new standard. Previously, the frequency was 27 MHz to 500 MHz at 1 meter from the device. Now it is 80 MHz to 1,000 MHz at 3 meters, with an additional requirement for 80% amplitude modulation of the signal.
For your test equipment to meet the 80% amplitude modulation requirement of the IEC 1000-4-3, you must determine the power required to generate a continuous-wave E-field and increase that by a factor of 3.24.1 In actual practice, however, you may need to increase the power even more because of cable and connector losses, insertion loss through the directional coupler, variation in the antenna characteristics and voltage standing wave ratio fluctuations. As a general rule of thumb, increase the power amplifier by an additional factor of 3.
For example, if you need to generate a field strength of 10 V/m to meet IEC 1000-4-3, you need an amplifier with 7 W of power. To accommodate the 80% amplitude modulation and losses due to equipment, multiply by 3.24 and then by 3 for a minimum of approximately 75 W.
But you need more than an amplifier to perform the required test. To meet the new standard, Amplifier Research recommends a package that includes a 100-W RF power amplifier, a log periodic antenna, a field monitor, an isotropic probe, a fiber-optic cable and an interface card.
Software Features
The automation of EMC measurements is a prominent topic in many testing departments, and software, is an important element of the discussion. With the right software, your job of testing, reporting and controlling is considerably easier for precompliance, compliance and production testing.
In precompliance testing, you will often look at sweep or scan data and want to determine which frequencies are problematic, said Cliff Morgan, EMC Product Marketing Manager at Tektronix. Since several test iterations must be performed, test speed and ease of use are key issues to investigate before selecting a software product.
Your software should compile a “suspect list” for frequencies that may need more testing. Precompliance testing software also should be able to define custom limits
which are user-defined specification limits, and compensate for antenna correction factors.
Compliance testing software must produce reports that can be submitted to regulatory agencies, said Dennis Handlon of Hewlett-Packard. The software also must correct for antennas, cables and amplifiers as well as archive measurement data and system setup information.
Compliance testing software also must be flexible yet easy to use, added Mr. Morgan. It should control the test receiver and external devices such as turntables, antenna masts, LISN leads and even movable absorbing clamps.
Software packages like the ES-K1 software from Rohde & Schwarz provide help with a script language. Several scripts for various tests and standards accompany the software, and you can modify them to fit your application.
What’s New
A glimpse of what’s coming down the pike for EMC software shows several new packages. A software product for radiated immunity testing from Amplifier Research helps you fully comply with the IEC 1000-4-3 requirements. It also can be used for precompliance troubleshooting and for testing to IEC 801-3 or MIL-STD-461.
Hewlett-Packard provides software with its receivers. It enables you to perform automatic peak, quasipeak and average measurements on signals above a defined limit. Sample test setup tables for European as well as military and FCC requirements are included.
Tektronix has introduced the Rohde & Schwarz ESPC receiver which includes test software. It downloads test setups to a PC and helps retrieve setups from the PC. It also accommodates automatic, semi-automatic and manual measurement modes. Color graphics of test results include displays of limit lines, scan data, peak, quasipeak and average test levels.
Reference
1. Amplifier Selection Criteria Required To Achieve IEC 1000-4-3 Testing, Amplifier Research, Application Note 0026, May 1995.
EMI/RFI Test Equipment
Software Automates
Immunity Testing
The SW1000 Electromagnetic Field Immunity Test Software provides automated immunity testing, data collection and report generation for the company’s power amplifiers and signal generators. The Windows®-based program has user-selected test parameters and a threshold mode for precompliance investigation of equipment susceptibility. Closed-loop field leveling enables precompliance troubleshooting and MIL-STD-461-type testing. Automatic data acquisition for EUT monitoring and data collection is provided for eight digital and 16 analog channels. $10,000. Amplifier Research, (215) 723-8181.
Compact Amplifier
Provides 250 Watts
The VZM-6993J1 Power Amplifier provides 250 W of power from 8 GHz to 18 GHz with a minimum gain of 32 dB. Gain stability is ± 0.25 dB/24 h. Input and output VSWR are typically 2.0:1 The amplifier has a -50 dBc typical noise rating. The harmonic content is -3 dBc at the upper band edge. Cooling is provided with an integral forced air blower. Communications & Power Industries, Satcom Division, (408) 496-6273.
Software Automates Commercial
And Military EMI Measurements
The HP 85869PC EMI software automates military EMI measurements such as MIL-STD-461 and commercial conducted measurements. The Windows-based software uses the HP E2060B BASIC programming language and a National Instruments AT-GPIB/TNT card. Sample test setup tables for military, FCC and EN requirements are included. The tables have information needed for equipment setup, limit lines and correction factors, and can be tailored with user subroutines and predefined frequency ranges. $8,460. Hewlett-Packard, (800) 452-4844.
Immunity Compliance Instrument
Tests to European EMC Norms
CEMASTER™ is a user-configurable EMC immunity compliance test instrument that performs testing to the six European Norm immunity standards. It features built-in dip and interrupt capabilities with transitions to multiple levels. It also has an internal magnetic field generator and a computer-controlled ESD simulator. Windows-based software controls the instrument and provides predefined routines for all required CE qualification tests. Starting at <$12,000. KeyTek, (508) 275-0800.
Precertification Test Receiver
Features PRFs to 10 Hz
The ESPC EMI Precertification Test Receiver features built-in preselection and interference measurements with pulse repetition frequencies as low as 10 Hz. An overload detection system for the complete receiver signal path, from the input to the IF stages, warns you of erroneous measurements. The unit covers a frequency range from 150 kHz to 1,000 MHz; has parallel detectors for average, peak and quasipeak readings, and has a frequency resolution of 10 Hz and 100 Hz. Starting at $28,950. Rohde & Schwarz, distributed by Tektronix, (800) 426-2200.
EMC Test System Performs
EU Compliance Checks
The BEST 96 EMC Test System combines the functions required for EU compliance testing for residential, commercial and light industrial electronic products. It contains a multifunction generator that provides surge and power, burst and ESD pulses to meet the EN 50082-1 requirements for single-phase powerline and dataline compliance testing. Ground planes, cables, ground straps, ground resistors and coupling clamps as well as instructions for performing the tests are included. The Windows-based software provides sequencing, customization, storage and data-analysis test-management tools. Starting at $18,400. Schaffner EMC, (800) 367-5566.
System Calibrates Antennas
And Performs SE Tests
The SRS-2100 Spherical Radiating Standard is comprised of a control unit, a radiating element and fiber-optic cable to calibrate antennas and perform shielding- effectiveness testing. The control unit has a temperature-controlled laser source that accepts radio frequency input, converts it to an optical signal and transmits the information to the sphere. The standard element has a frequency range from 10 MHz to 2.5 GHz, and the low-frequency version ranges from 15 kHz to 50 MHz. $37,500. Seth, (814) 255-4417.
Replacement 8-28-96
Power Frequency Tester Meets
IEC 1000-3-3 Requirements
The PHF 555 Single-Phase Power Frequency Test System meets the IEC 1000-3-2 and 1000-3-3 requirements for harmonic and flicker measurements. It also generates voltage and frequency fluctuations, interharmonics and harmonics. The system assesses power line distortions created by electrical and electronic equipment. It provides analysis up to the 40th harmonic and automatically detects Class D waveforms. Voltage dips, interrupts and variations are programmable and have a phase accuracy of 1° . $22,950. Haefely Trench, (703) 494-1900. Circle 278
(PHF 555) no pix
System Performs Radiated
And Conducted Emissions Tests
The DSI-200 Automated Test System performs commercial and military EMI radiated and conducted emissions testing. Test plans are provided for FCC, ANSI, CISPR and MIL-STD requirements. The basic system consists of a receiver, a PC, a GPIB interface board, a 500-kS/s data acquisition module and a spectral display module with a 1-MHz to 8-MHz span. Quasipeak, peak, rms and average detection modes are provided with 30 bandwidths ranging from 200 Hz to 15 MHz. The system frequency ranges from 1 kHz to 1.9 GHz. $59,500. Dynamic Sciences, (818) 226-6262.
Copyright 1996 Nelson Publishing Inc.
October 1996