Measurement Peripherals (600's)

Section 600 Content Consideration

Measurement Peripherals and specialised hardware is covered by this section. The first sub section is Thru-line Attenuators DC-18GHz. The products are mainly those of “Bird” or “Weinschel”. The ranges run from 3dB to 20dB units. Be sure to choose the correct wattage to cover your application. Generally, the wattage value should be about 2dBs above the power in watts of the amplifier one is using. Almost all units are fitted with “N” connectors (male to female). Some of the larger wattage types exhibit a polarity, so take care which way around they are connected otherwise damage will occur. Most of the ranges have a working frequency from DC to 2GHz but there are dedicated microwave devices working up to 18GHz. A couple of laboratory hand stepped attenuators have been included in the section.

The second sub section Terminal Loads covers loads all of which are 50 Ohms working from DC up to 2GHz with a special microwave load working up to 18GHz (item 656). NOTE: Please do take care when physically handling the in-line coaxial attenuators & loads. If dropped to the ground or on any hard surface, typically when attached to cables, the peripheral etched 50 Ohm termination can crack destroying its frequency & attenuation characteristics.

A third sub section LF and RF Filters has been devoted to high pass filters offering a limited selection which play a role in EMC measurements. These will generally be used with receiver front ends.

The fourth sub section  is Directional Couplers and coaxial switches. A full range of Dual Directional Sampling Couplers can be found working from 10KHz through to 18GHz. They are mostly used in both radiated & conducted Immunity systems. Be aware of the sampling port attenuation & type of connector. An average sampling figure is some 40dB down which means the power sensor must be able to detect this if you are using relatively low powers. Make sure the thru-power handling capability of the coupler is also adequate for the size of amplifier being used. All this information can be found in the main catalogue or on the Web site.

Finally, Auxiliary Test & Monitoring Equipment consists mainly of power meters and camera systems. The camera systems come as two types. Item 680, the Fujitsu, is a standard chamber camera powered from the mains with a coaxial transmission out to a VDU. Item 681 is a more specialized device used where the invasion of a camera within the field volume is unacceptable. Essentially item 681 is a standard camera with a 3 metre long fibre lens which can feed through into the chamber or cell to observe small readouts on instrumentation etc. whilst itself remaining RF transparent. A fibre light source accompanies this device. With the Boonton power meters you will need to use a directional coupler if measuring RF power. Similarly for the Rohde & Schwarz although one of the R & S systems has a combined power sensor & coupler (item 685A). Make sure you understand the reading capability of the power sensor used with your power meter. Some are thermal devices and will read true rms power with complex waveshapes. Others are really probes with diode rectifiers and rely on a 50 Ohm target impedance to give a reliable power reading. One other item within the group is a “PowerVisa” mains disturbance analyzer. This device simply plugs into any 13 amp outlet & will record for as long as connected all transients that occur on the line.

A recent addition to the hire facility is the inclusion of the ETS-i4334 Printed circuit board Scanner. A device for providing the EMC Engineer with a signal level versus location relative to the component & track layout on any pcb.  An invaluable tool when working on EMC problems at board level. This can be hired out as a system, which will include as a minimum, just the Scanner and a laptop preloaded with dedicated ETS software. If the customer cannot supply their own receiving device then we offer options to hire the scanner with a receiver or spectrum analyser from section 100 but at a consolidated price. If you have already have a receiving device then check with either the Ets web site (More info: www.etsi.co.uk) or ourselves that there are drivers written within the existing software. The End user can then connect up one of five receiver/analysers as listed under item 687 in the main catalogue/Web site.

A further alternative is to use the item complete as a working system here at EMC Hire Ltd. The End user is then charged by the hour. (see section 900, item 929).