The Langer A300-2 Set consits of two sensors, which allow for displaying oscilloscopically analog signals under EFT/ESD/RF interference potential free. Disturbed signals can be easily detected. In the device under test the sensor transforms the measured logic signals into optical signals. The optical signals are transmitted via a fibre optical cable to the optical receiver which transforms them into electrical signals. These can be presented with an oscilloscope or can be used for controlling other devices. The system is suitable for monitoring signals or devices under test in an anechoic chamber or for EMC optimizing of hard-and software. For signal detecting within the device under test several sensor types AS300 or AS350 with different measuring ranges are available.
Includes:
- 2x AE 300, Optical Receiver
- 2x AS 300, Optical Sensor, Analog ± 10 V DC
- 2x LWL Ø 2.2 mm 6 m, Optical Fibre, Single 6 m
- 1x NT FRI EU, Power Supply Unit
- 1x A300-2 acc, Accessories
- 1x A300-2 case, System Case
- 1x Analog m, User Manual
Measurement under interference conditions
Measurement of analogue electrical signals under extreme electromagnetic stress such as:
- Coupling of radiated or conducted RF emissions
- Fast transients burst/ESD
- High potential (high voltage)
EMC tests as the main field of application:
- Radiated RF emissions EN 61000-4-3: 80 MHz - 1 GHz, 80% AM (1 kHz), anechoic chambers TEM cells stripline,
- Conducted RF emissions EN 61000-4-6: 40 Veff, 150 kHz - 230 MHz, 80% AM (1 kHz)
- Burst EN 61000-4-4
- ESD EN 61000-4-2
Measured signals:
- Supply voltages (switching controllers, linear controllers),
- Reference voltages,
- Digital signals (optical couplers, optical receivers),
- Analogue signals (operational amplifiers, ADC, DAC).
Specific measurement technology:
To measure analogue signals under extreme interference conditions, measurement technology is needed that
- itself is not affected by disturbance fields and thus does not simulate any disturbance in the equipment under test (EUT).
- can be connected to the EUT in a decoupled way, i.e. connecting the probe head does not result in the development of additional disturbance current paths through which disturbances can penetrate or be discharged.
The A100 set / A200 set / A300 set optical fibre measurement systems meet these demands.
Specific measuring task
Analogue electronic modules are generally influenced in EMC tests when RF, modulated by 1 kHz, is applied to the EUT. This influence is due to the fact that the infiltrated RF disturbance is demodulated at PN junctions of the electronic circuit. This generates signal level fluctuations or 1 kHz disturbance signals. The 1 kHz disturbance signal is produced through modulation of the RF disturbance by 1 kHz.
Relatively slow disturbance signals with a fundamental wave of 1 kHz, which mostly interfere with analogue circuits, are charac-teristic for RF disturbance coupling.
Figures 1 to 6, on the next page, show examples of useful signals that were subjected to disturbances. The deviation of the signal form from the sine wave varies, i.e. the disturbance signal also contains a harmonic component as well as the fundamental one. The task is to correctly measure these relatively slow disturbance signals under extreme RF interference conditions.
The A100 set / A200 set / A300 set measurement systems are ideal for these conditions because of their high disturbance immunity.
Examples of disturbed useful signals
Signals were measured with the AS 100 optical fibre probe.
Radiated RF emissions: 250 MHz, 80 % amplitude-modulated by 1 kHz
EUT: operational amplifier circuit; RF coupling via an operational amplifier input; the disturbance signal was measured on the output.
