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Gigahertz Solutions ME 3951A, Руководство пользователя

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Gigahertz Solutions ME 3951A Скачать руководство пользователя страница 14

Frequency Analysis 

(AC Electric and Magnetic Fields)

An AC electric or magnetic field is not only defined by its field strength, but also by the frequency
with which the polarity of the field changes. We encounter various common frequencies:

-

Overhead railway wires operate at 16.7 Hz (only in Europe).

-

The electric power grid (home wiring, high-tension power lines) operates at a 60-Hz frequen-
cy in North America and at a 50-Hz frequency in Europe. So-called natural harmonics are the
multiples of the respective fundamental frequency (50 Hz or 60 Hz).

-

In addition, various electronic devices are used in our homes that generate a variety of fields
with higher frequencies in the kHz range (artificial harmonics) such as switch-mode power
adapters ("transformers"), ballasts of fluorescent tubing and energy saving lamps as well as
dimmer switches with so-called switch mode technology and the like.

For the assessment of a certain area and especially with regards to appropriate remediation stra-
tegies, it is very useful to know how many of the different frequencies contribute to the total expo-
sure. An exposure caused by overhead railway wires, for example, cannot be remedied by instal-
lations of the homeowner. However, it is possible to avoid certain signals of the kHz range by
choosing devices without such emissions (e.g. incandescent lamp instead of fluorescent tubing)
(only in Europe).

The ME 3951A field meter offers you different options to analyze frequencies:

Frequency Analysis with Frequency Filter Module F1B2H31

Picture 21

Picture 22

Depending on the testing situation, 

GIGAHERTZ SOLUTIONS

®

offers several different frequen-

cy filter modules for the ME 3951A. The Frequency Filter Module F1B2H31 (Picture 21/22) alrea-
dy supplied with the field meter is specifically designed for building biology needs. The following
frequencies can be selected:

1) 5 Hz to 400 kHz 

=

Entire TCO frequency range, best suited for tripod measurements 

2) 16.7 Hz

=

4th order band pass filter with Q-Factor 10 for the frequency of
overhead railway wires (only in Europe)

3) 50 Hz to 400 kHz

=

5th order high pass filter for the electric power grid and its harmo-
nics

4) 2 kHz to 400 kHz

=

5th order high pass filter for so-called artificial harmonics above 2
kHz. This frequency range corresponds with band 2 of the Swedish
TCO guidelines.

In order to measure fields of overhead railway wires or harmonics, first the respective filter in the

14

© by 

GIGAHERTZ SOLUTIONS

®

GmbH, 90579 Langenzenn, www.gigahertz-solutions.com

Measurement Instructions

GIGAHERTZ

SOLUTIONS

R

Содержание ME 3951A

Страница 1: ...SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIG SOL GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS G SO GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS G S GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHERTZ SOLUTIONS GIGAHER SOLUT...

Страница 2: ...d Swedish guidelines for com puter monitors TCO MPR covering the entire frequency range from 5 Hz up to 400 kHz We appreciate the confidence you showed when purchasing the ME 3951A field meter With the confidence that your expectations will be met we wish you great success in collecting useful information with this field meter by the manufacturer GIGAHERTZ SOLUTIONS GmbH D 90579 Langenzenn All rig...

Страница 3: ...ip touches the current carrying phase conductor To prevent shock hazards or the destruction of the field meter neither the instrument itself nor the adapter should ever come into contact with water The penetration of water into the case may lead to the destruction of the electronics inside Field meters are not to be stored outdoors or used during rain Clean the case only from the outside using a s...

Страница 4: ...d on On Field meter turned on Off Field meter turned off see pages 7 11 18 Frequency Filter F1B2H31 16 Hz Band pass 50 Hz High pass 2 kHz Highpass for buil ding biology assessments to identify railway systems elec tric power grid as well as har monics of higher frequencies see pages 11 12 14 Light diode comes on while battery is being charged see page 18 Button to be pressed for the display of the...

Страница 5: ...d in order to avoid short circuit damage of the instrument see pages 17 Battery Compartment LC Display 3 5 digit display of the measurement value RMS including field type and low batt indicator see page 19 2 Miniature Speakers in a magnetically shielded circuit Pegs to hold the rechargeable battery in place Picture 02 Frequency Filter Module F1B2H31 Can be replaced with modu les featuring other th...

Страница 6: ...for opening the case to change batteries or frequency filter modules 9 Rechargeable battery with 9 V nominal voltage Depending on shipping conditions it is sometimes already inserted into the field meter Getting Started Turning On If no display is activated insert rechargeable battery See section Changing Battery Charging If display shows low batt indicator charge battery or insert a fully charged...

Страница 7: ...he front of the case with your fingers as shown in picture 04 Picture 04 Due to your fingers mass potential a quasi AC electric field is created whose strengths is reflected through higher measurement values on the display and the faster rattling noise from the spea ker Defining the Offset Turn on the instrument and set the switch field type to the test position On the left hand side of the displa...

Страница 8: ... as an appliance is turned on there is current flow and an AC magnetic field is added 4 Beside the field strength AC electric or magnetic fields are also characterized by their fre quency We distinguish between the low frequencies of the ELF and VLF range between 5 Hz and 400 kHz as defined by the MPR TCO guidelines for the assessment of computer monitors as well as all the higher frequencies incl...

Страница 9: ...s of the situation Thus appropriate remediation strategies can be assigned 5 Start with the measurement range 200 nT Vm Only if the display goes in overload because of rather high ambient field strengths switch to the higher range 2000 nT Vm 6 Ideally all measurements are to be repeated during various times of the day and on different days of the week in order to identify fluctuations 7 The additi...

Страница 10: ...r Picture 13 see also footnote 1 Picture 11 Picture 12 Picture 13 1 The electric field strength measured with ground reference always depends on the geometry of the field source and the sensor the distance between sensor and field source as well as ambient potentials Following TCO guidelines the ME 3951A is calibrated according to the TCO calibrated field meter Radians Innova Enviromentor EMM 4 Se...

Страница 11: ...ing in order to identify the field source In areas where people spend substantial amounts of time such as in bed or at a workplace check all directions as mentioned above and make note of the orientation of the field meter at maximum readings In such a position a reference measurement of the absolute value should be taken as close to the body as possible After having checked all directions the max...

Страница 12: ...Then you follow the direction which continues to show increasing measurement values Simply keep the field meter aligned in the direction of the maximum readings For an accurate measurement however hold the instrument very steady or put it down at a relevant measurement point In the important places where we work sit or sleep all three dimensions of AC magnetic fields should be checked each time Pr...

Страница 13: ...direction of the resultant field which is also called substitute field The photos for pictures 16 through 18 showing the single measurements of the three dimensions as well as picture 20 were taken in a kitchen during a typical testing session If you would insert the display values in the above equation the result would come very close to the value which is dis played in picture 20 There the field...

Страница 14: ...ied by instal lations of the homeowner However it is possible to avoid certain signals of the kHz range by choosing devices without such emissions e g incandescent lamp instead of fluorescent tubing only in Europe The ME 3951A field meter offers you different options to analyze frequencies Frequency Analysis with Frequency Filter Module F1B2H31 Picture 21 Picture 22 Depending on the testing situat...

Страница 15: ...rectly to the AC output of the field meter by means of the supplied adapter At the AC output a DC offset of maximum 50 mV is applied It is standard in oscilloscopes and spectrum analyzers that this DC offset is usual ly suppressed by a capacitive coupling In case the peripheral analysis instruments are connected to the power grid including grounding conductor the grounding of the field meter shoul...

Страница 16: ...att is displayed the Auto Power Off function will be activated in order to prevent the battery from becoming completely discharged which otherwise might destroy the rechargeable battery 24 hour data logging can be supported through a connection to the electric power system via the adapter or a 12 V battery In the event a power outage occurs during data logging the recharge able battery in the inst...

Страница 17: ...ture 27 Removing Batteries Change batteries only while the instrument is turned off After having opened the cover the rechargeable battery including its clip can be removed or lifted out sideways In order to remove the battery clip from the rechargeable battery slip the small end of the wedge as far up between both contacts as possible then move the wide end of the wedge up and down Thus the clip ...

Страница 18: ...ge 12 24 VDC are correct In order to start charging the battery turn on field meter and then off just once After that leave it turned off The green light of the diode will shine during the charging After about 11 hours the charging mode will be turned off automatically Low Batt 1 When the field meter is turned on and the two dots appear in the display low batt the battery is in a low state Using t...

Страница 19: ...Check Since the integrated rechargeable battery is not always charged completely it is possible to find out the remaining operating time as well as the proper functioning of all display segments by pres sing the Batt Check button 1 In order to check the battery status simply turn on the field meter press the button and continue to keep it pressed If the display shows 1999 or 1888 the instrument is...

Страница 20: ...r 3 500nT 1dB 500nT 3dB 500nT Typical frequency response curve 0 20 40 60 80 100 120 1 10 100 1000 10000 100000 1000000 frequency Hz electric field strength V m ohne_Filter 100 0V m Filter 1 100 0V m Filter 2 100 0V m Filter 3 100 0V m 1dB 100 0V m 3dB 100 0V m Power Supply Integrated rechargeable battery with a soft b ba at tt te er ry y c ch ha ar rg ge e m ma an na ag ge em me en nt t to protec...

Страница 21: ...eje Y tolerancia incrementada Sensor de campo eléctrico conforme TCO TCO Light acoplable opc opc Características Salidas AC y DC Función auto power off Equipamiento y accesorios opcionales 9 V Batería incl incl incl Acumulador NiMH recargable incl incl Fuente de alimentación incl incl Certificado de calibración KAL NF opc opc Dislpay externo DP3000A opc opc opc opc opc Cable toma a tierra incl inc...

Страница 22: ...gran tamaño 4 cifras Presentación de la frecuencia mediante LED multicolores o en valor numérico Señal acústica tipo Geiger volumen configuración de valores máximo Interface para tiempo real Infrarojo radiotransmisión opcionalmente opc opc Grabador de datos interno logger Transmisión 110 000 Samples seg Maximas son transmitidas y archivadas hasta 10 seg Sobre tarjeta SDHC Simultánea y selectiva de...

Страница 23: ...ncia alta frecuencia 1 D est 2010 linea profesional 3 D est 2010 C o r r i e n t e d e f e r r o c a r r i l C o r r i e n t e d e c a s a A r m o n i c o s n a t u r a l e s A r m o n i c o s a r t i fi c i a l e s B o m b i l l a d e b a j o c o n s u m o A d a p t a d o r d e c o r r i e n t e N o r m a t i v a d e T C O A d a p t a d o r d e c o r r i e n t e R a d i o C B r a d i o F M T V T ...

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