SELECTIVE RADIATION METER SRM-3000 Narda Safety Test Solutions Srl Via Leonardo da Vinci, 21/23 20090 Segrate (Milano), Italy Phone: +39 02 2699871 Fax: +39 02 26998700 E-mail: [email protected] www.narda-sts.it Narda Safety Test Solutions GmbH Sandwiesenstrasse 7 72793 Pfullingen, Germany Phone: +49 (0) 7121-97 32-777 Fax: +49 (0) 7121-97 32-790 E-mail: [email protected] www.narda-sts.de Narda Safety Test Solutions 435 Moreland Road Hauppauge, NY 11788, USA Phone: +1 631 231-1700 Fax: +1 631 231-1711 E-mail: [email protected] www.narda-sts.com FREQUENCY-SELECTIVE, ISOTROPIC MEASUREMENT, EVALUATION, AND RECORDING OF HIGH FREQUENCY ELECTROMAGNETIC FIELDS NSTS 0307-E0211C Technical advances, errors and omissions excepted

2 3 SELECTIVE. You can’t hear electromagnetic radiation. If you could, there would be music in the air. On some rooftops, there are whole choirs and orchestras of antennas. Are they too loud? Do some stand out as soloists? Test equipment that captures the whole frequency spectrum measures the total radiation level. That’s good enough, if the permitted immission limit value is not exceeded. But what if it is? Then you need to find the reason. A frequency-selective test set is the answer. It separates the GSM choir from the VHF orchestra, identifies the loudest “voices” individually and shows their...

4 5 100k 1M 10M 100M 1G 10G 100G 10 100 0,1 [Hz] 1000 [V/m] occupational general public ISOTROPIC. You can’t see electromagnetic radiation. Even so, it behaves in much the same way as visible light. Rod antennas radiate in a circular pattern in one plane, sector antennas illuminate a certain angle, and concave reflectors send out a focused beam. Measuring antennas are similar. A unidirectional antenna only has two “eyes” – one lobe on each side. That’s no use if they’re both looking in the wrong direction to see the transmitter. Only an isotropic, i.e. non-directional antenna can see the whole...

6 7 RADIATION PROOF. You can’t feel electromagnetic radiation. Mechanical robustness is easy to assess, by taking an object in your hands. Resistance to electromagnetic radiation can only be shown by measurement. The field strength emanating from a radio broadcast antenna can be ten thousand times more than that from a mobile phone channel – a real challenge for any test set. It needs to be highly sensitive on the one hand, yet on the other hand, strong radiation must not be able to bypass the test antenna and enter the electronic circuits directly, leading to wrong results or even impaired function....

8 9 REVOLUTION: A selective measuring instrument especially designed for safety related concerns in electromagnetic fields. THE SRM FROM NARDA. FOR FREQUENCY-SELECTIVE, NON-DIRECTIONAL MEASUREMENTS. IN THE PALM OF YOUR HAND, ANYWHERE. Selective and complicated, or quick and easy broadband? No need to make this choice any longer. The SRM measures selectively and gives you reliable results. Without additional cables or an external PC. We at Narda have designed it especially for the safety concerns in electromagnetic fields. So it’s handy, battery operated, and radiation proof, and you can take...

10 11 EVOLUTION: There’s no mistaking the origins of Narda’s family of instruments. The SRM is precision measurement technology in a workday package. High tech inside, rugged and simple outside. Just switch on and measure – and get reliable results. THE SRM FROM NARDA. EASY, FAST, PRECISE MEASUREMENTS. IN THE PALM OF YOUR HAND, ANYWHERE. Narda has achieved a breakthrough with the SRM: A frequency-selective, precision measuring instrument that is operated just like a simple, broadband, handheld tester. That saves time. The SRM is especially designed for safety related concerns in electromagnetic...

12 13 STANDARDCOMPLIANT WEIGHTING. The measured values of field strength are physical quantities, so they are “neutral” results. The resulting radiation exposure is the relationship between the measured field strength and a frequencydependent limit value, which makes it a “weighted” result. These limit values are set at different levels by different bodies: the ICNIRP (International Commission on Non-Ionizing Radiation Protection), the IEEE (Institute of Electrical and Electronic Engineering) and others. The occupational standard in Germany is known as BGV B11 (Trades Union Regulation for Health...

14 15 Safety Evaluation with a single axis measuring antenna? No problem with the SRM. First axis, first measurement, and the SRM shows the first intermediate result. Turn the antenna, make the second measurement, and the SRM shows the updated result. Same again for axis number three; the third measurement gives the final result. SELECTION, DEMODULATION, EVALUATION. The SRM evaluates the results according to the applicable safety standards and shows the results down to each separate radio channel and cell, or collected together according to operator, communications service, or entire radio frequency...

16 17 SPATIAL AVERAGING How high is the average field exposure determined over the volume of the human body? The SRM averages several spatial values continuously or discretely and displays the result directly at the end of the procedure. MAXIMUM VALUES AND AVERAGES. Where is the field strength highest in the room? At what frequency? When do peak values occur, and how long do they last? The SRM shows all this directly. And if you need to know the average values instead, the SRM shows them, too. THE SRM FROM NARDA: ANALYZES, AVERAGES, AND INTEGRATES. IN FREQUENCY, SPACE, AND TIME. If you need to...

18 19 AUTOMATICALLY CORRECT. Strictly speaking, the SRM doesn’t measure the electromagnetic field. It measures the voltage that the field induces at the output of the measuring antenna. The so-called antenna factor must be known before the results can be shown as field strengths. Precision measurements demand that this factor is determined for each antenna separately at various frequencies and then applied during evaluation. No problem with Narda measuring antennas. The antenna factors are stored in the antenna itself during calibration. The SRM recognizes them and applies them automatically....