RadiMation Application Note 148

How to perform a MIL-STD-461 CE101, Conducted Emissions, audio frequency currents, power leads test

This application note explains how the MIL-STD-461 CE101, Conducted Emissions, audio frequency currents, power leads test can be performed with RadiMation^®.
The MIL-STD-461 CE101 test measures conducted emissions of low-frequency currents (30 Hz to 10 kHz) on power leads from a device under test to ensure compliance with electromagnetic interference (EMI) standards.

The exact requirements and test methods for the CE101 are specified in the MIL-STD-461.

Necessary equipment

The following devices are necessary to execute this test:

• Receiver
• Current sensor
• LISN
• Cable

Configuration of the test sites

The configuration of the equipment is a current sensor connected with a cable to a receiver.

The configuration of the test site should contain the following devices:

#	Device name	Tab in testsite configuration window	note
	Current sensor	Devices 2	Current sensor
	Spectrum Analyser	Devices 2	The receiver used for the test
Cables
①	Cable preamp -> analyser	Cables	Cable with a correction file specified for the cable loss

Note:

The LISN is only used to decouple and it is not needed to specify and configure this in RadiMation®

Configuration of the Current sensor

The current sensor needs to have the correction data applied which is normally known by the manufacturer or provided by a calibration company. The correction data is often expressed in Ohm (Resistance).

In RadiMation^® this can be configured by creating a correction file, which contains a 'Frequency' and a 'Correction' column. Then specify the frequencies and the correction values in the correction file. The correction values are expressed in Ohm.

It is also possible to specify the values in dBOhm, in that case the Correction column needs to be removed and then a new column should be added of type 'Resistance' with the unit dBOhm.

After creating a correction file and saving it to disk it is now important to select this correction file in the Current Sensor device driver.

For more information about the current sensor correction see the Current sensor impedance section in Chapter 14 of the RadiMation^® manual.

Perform the test

To perform the actual CE101 test, start a Conducted Emission Multiband test:

    Tests

       Conducted Emission

          Multiband

The complete test from 30 Hz up to 10 kHz has different settings for different frequency bands. A single multiband test can be configured with 2 bands, each using their applicable frequency range, measure time and bandwidth.

Band	Frequency range	RBW	Step size	Measure time receiver	Measure time FFT receiver
Band 1	30 Hz - 1 kHz	10 Hz	5 Hz	0.15 s	1 s
Band 2	1 kHz - 10 kHz	100 Hz	50 Hz	0.015 s	1 s

The requirements regarding the RBW and measure time should be taken from 'Table II' of the MIL-STD-461.

In the following test configuration an EUT for "Surface ships and submarine applications, DC" is tested.

Start

The start frequency of the test. For example 30 Hz.

Stop	The stop frequency of the test. For example 10 kHz.

Reference Level

The reference level set in an analyser, not used in a receiver

Attenuation

The attenuation set in the receiver

RBW	The RBW set in the receiver, see 'Table II' with different bands for possible values

Step size

The step size set in the receiver, see 'Table II' with different bands for possible values

Measure time

The measure time set in the receiver, see 'Table II' with different bands for possible values

Preamplifier

The preamplifier setting set in the receiver

Traces

The type of trace set in the receiver, for MIL-STD-461 CE101 only a peak detector is used

Test Equipment

The equipment used for the measurement

Location type

As a current sensor is used to measure the emission Current Sensor has to be selected for Location type

Limit Lines

The applicable limit line can be added, in this case "MIL-STD-461G CE101-1 Surface ships and submarine applications, DC"

All peaks above x dB below the limit line

Which level above x dB below the limit line should detect peaks, CE101 does not require that a final peak measurement is performed on peaks. Therefor this value is not important and can be left to 0

Peak detection

CE101 does not require that a final peak measurement is performed on peaks, thus peak detection can be set to No peaks.

Final peak measurement

CE101 does not require that a final peak measurement is performed on detected peaks, thus all detectors can be left unchecked.

When all parameters are configured for the CE101 test, press Start Test to perform the conducted emission measurement.

Review the measurement

Once the test is finished, the results of this test are stored in the EUT file and available as one of the performed Tests in the EUT file. Selecting the corresponding test result and pressing on Info will show the test results again.

Conclusion

The MIL-STD-461 CE101 test is using different receiver settings depending on the frequency band. All these settings can be easily configured in a "Test Setup File" and tested with RadiMation^®. The result of the emission measurement is shown with a dBuA unit, and can be compared to the limit line as specified by the standard.

ElectroMagnetic Interference: The electromagnetic energy that interferes with how an EUT works

Line Impedance Stabilisation Network

Resistance expressed in Ohm in dB values.

• 1 Ohm = 0 dBOhm

• 2 Ohm = 6 dBOhm

• 10 Ohm = 20 dBOhm

Resolution BandWidth

Equipment Under Test

Direct Current

Decibel