ELF Magnetic Field Meter
Contents
1. A second switch controls the desired low frequency cutoff A Low Battery LED glows when the batteries are low If the low Battery indicator remains on replace both of the batteries which are accessible from the back side of the meter case instructions for replacing batteries may be found in the Maintenance section of this manual It is normal for the LED battery indicator to briefly blink while turning the switch to various ranges and when turning the instrument off When beginning field measurements successively turn the range switch to the right increasing the instrument s sensitivity until an upscale reading on the meter is obtained Most accuracy is achieved when the meter reads approximately midscale At each range setting while holding the meter in one hand rotate the sensor with the other hand so as to obtain a maximum indication on the meter Because the sensor is capable of measuring only one polarization component of the magnetic field at any specific time there are two methods that can be used for measurements In the majority of cases it is sufficient to orient the sensor so that a maximum indication on the meter is observed In many instances this will be a measurement of the resultant magnetic flux density The sensor must be rotated about three axes which are each perpendicular to one another This can be quickly accomplished with a little practice 17 In other cases the root sum squared resultant value of flux density2. flux density between the coils in milligauss mG is calculated While the HI 3624A indicates magnetic flux density B in units of milligauss the flux density in microtesla or magnetic field strength H in milliamperes per meter may be obtained via the following relations 1 microTesla 10 mG 1 mG 80 milliamperes per meter mA m 12 4 0 Practical Application and Use Before operating any components follow the CAUTION safety information in the ETS Lindgren Product Information Bulletin included with your shipment Example Application Power Lines Magnetic fields near overhead power lines can be easily measured with the HI 3624A An approach commonly used to characterize power line fields is to measure the flux density along a straight line which passes perpendicular to the power line Generally readings are first taken along the length of a span of the power line to identify the point at which the greatest flux density exists Then at this point take the readings perpendicular to the power line Take readings every five to ten feet and orient the sensor for maximum reading A magnetic field flux density profile can then be developed This method is outlined by the Institute of Electrical and Electronics Engineers IEEE in the American National Standards Institute ANSI standard 644 1987 A similar approach may be used for measuring the flux density produced by buried lines In this case the area must be explored by
3. may be obtained by taking three orthogonal measurements of the field in this case the sensor is successively oriented in three mutually perpendicular directions around a fixed point and the individual readings recorded The mutually perpendicular directions will be denoted as X Y and Z The resultant flux density is then found by forming the root sum squared value from the individual readings as follows B Bx By Bz B resultant flux density B Reading in the X direction B Reading in the y direction B Reading in the Z direction It does not matter which orientation of the field sensor is used for the X orientation but the Y and Z orientations must be perpendicular to one another and the X orientation The user may select the lower frequency of the band pass for the instrument as either 30 Hz or 5 Hz It should be noted that when the instrument is switched to the 5 Hz lower frequency cutoff the unit will be very sensitive to motion of the sensor since movement within the earth s constant field will appear as a signal to the instrument When the sensor is accelerated or rotated within a constant field there will be an output from the sensor at a frequency corresponding to the movement and this will usually include frequency components greater than 5 Hz Consequently during such movement the meter will typically show significant upscale indications The 5 Hz frequency cutoff setting is primarily useful for measurements
4. walking about with the meter simultaneously moving the sensor in various orientations until the region of maximum flux density is found 13 Residential Measurements Magnetic fields found in home environments are highly variable depending on location within the home This variability is strongly related to the distribution of the wiring in the home the location of electrical appliances and occasionally the location of plumbing lines or other metallic structures within the ground which may form low resistance paths for electrical ground return currents Establishing what the ambient magnetic field environment is in a home usually requires numerous measurements throughout the home with at least one measurement within each room Normal practice would include at least one field measurement taken near the center of each room A more thorough approach would include five measurements in each room one at the center and one near each corner of the room A reasonable technique is to position the sensor at a point approximately one meter from each room corner for the flux density measurement This avoids to an extent placing the sensor immediately next to wiring which may be hidden within the walls of the room and which may yield unrealistically high values of flux density compared to what most individuals within the room might be exposed Surveys of the areas near electrical appliances will usually reveal higher values of flux density due to the c
5. For the steps to return a system or system component to ETS Lindgren for service see the Product Information Bulletin included with your shipment This page intentionally left blank 10 3 0 Specifications Electrical Specifications Frequency Response 5 to 2000 Hz Flat 5Hz 3 dB 2000 Hz 3 dB lt 5 Hz Falling 80 dB decade gt 2000 Hz Falling 80 dB decade Detector Response True rms field indication for accurate measurement of non sinusoidal waveforms Full scale ranges of 2 mG 20 mG 200 mG 2 G 20 G Sensitivity f 5 at calibration frequencies of 50 100 500 and 1000 Hz Accuracy Within 5 at calibration frequencies of 50 100 500 and 1000Hz Linearity 2 Physical Specifications Power Two 9 volt alkaline batteries Battery Life Up to 120 hours intermittent use External Multi Turn Loop Sensor Inside diameter 110 mm Outside diameter 116 mm Area 0 010 m Cable Length 1 2m 11 TYPICAL FREQUENCY RESPONSE for HI 3624A Response dB 1 10 100 1000 10000 Frequency Hz Instrument accuracy is derived from a field calibration using a one meter diameter pair of Helmholtz coils for establishing an accurately known magnetic field flux density A precisely controlled and measured sinusoidal current is driven through the Helmholtz coils and based on the dimensions of the coils the magnetic field
6. Model HI 3624A ELF Magnetic Field Meter User Manual NEIS LINDGREN HOLADAY EMF MEASUREMENT ETS Lindgren L P reserves the right to make changes to any product described herein in order to improve function design or for any other reason Nothing contained herein shall constitute ETS Lindgren L P assuming any liability whatsoever arising out of the application or use of any product or circuit described herein ETS Lindgren L P does not convey any license under its patent rights or the rights of others Copyright 1991 2009 by ETS Lindgren L P All Rights Reserved No part of this document may be copied by any means without written permission from ETS Lindgren L P Trademarks used in this document The ETS Lindgren logo is a trademark of ETS Lindgren L P Revision Record HI 3624A ELF Magnetic Field Meter MANUAL Part H 600044 Rev B Revision Description Date Initial Release April 1991 A Added CE updated January 2000 B Updated branding Revised to July 2009 meet Style Guide specifications reformatted to half size PIB included with release Remove HI 3624 reference Remove VDT reference Table of Contents Notes Cautions and Warnings esee V 1 0 Introduction niae tere eeetereeieeee 7 Standard Configuration 8 ETS Lindgren Product Information Bulletin eeeeeeeeese 8 2 0 Maintenance eeeeeee
7. at fixed coil positions For area surveys of ELF fields the 30 Hz cutoff will be more useful 18 Appendix A Warranty gt See the Product Information Bulletin included with your shipment for the complete ETS Lindgren warranty for your HI 3624A ELF Magnetic Field Meter DURATION OF WARRANTIES FOR HI 3624A ELF MAGNETIC FIELD METER All product warranties except the warranty of title and all remedies for warranty failures are limited to one year Product Warranted Duration of Warranty Period HI 3624A ELF Magnetic Field Meter 1 Year 19 This page intentionally left blank 20 Appendix B EC Declaration of Conformity SVETS UINDGREN C Declaration of Conformity We ETS Lindgren L P 1301 Arrow Point Drive Cedar Park TX 78613 USA declare under sole responsibility that the Model Part Number HI 3624A Model Part Name ELF Magnetic Field Meter Date of Declaration Affirmation Date 07 April 2009 to which this declaration relates meets the requirements and is in conformity with the relevant EC Directives listed below using the relevant section s of the following EC harmonized standards and other normative documents Applicable Directive s pm G gt au Hf 2 f d ETS Lindgren L P ETS Lindgren LP Bryan Sayler General Manager James C Psencik Vice President of Engineering The authorizing signatures on this Declaration of Conformity document author
8. e of 30 Hz to 2 kHz The Model HI 3624A provides for a switch selectable measurement range from 5 Hz to 2 kHz It finds application in the measurement of magnetic fields associated with electric power lines and electrically operated appliances The HI 36244A is a single axis flux density meter designed to be responsive to either sinusoidal or complex magnetic fields It directly displays the root mean square rms value of magnetic flux density on an analog meter The sensor consists of a multi turn loop connected to the instrumentation readout package via a one meter long cable The separate loop sensor provides for orientation of the sensor relative to the various magnetic field polarization components This allows quick assessment of the greatest flux density value while conveniently holding the instrument for easy meter reading This feature makes the HI 3624A especially useful for rapid large area surveys of magnetic fields The field sensor loop is electrically shielded consequently the response of the HI 3624A is solely due to magnetic fields No interference is caused by ambient strong electric fields like those found beneath high voltage overhead electric power lines or nearby radio or television stations The HI 3624A has a wide dynamic measurement range The range provides for full scale ranges of as small as 2 milligauss to as great as 20 gauss This large dynamic range makes the HI 3624A convenient for measurement of ambient re
9. eieeseseeeeeen enne nena nnn nn nnns 9 Battery Replacement Annual GCalibration E rep a dE td Ha etd Service Procedures ciue p ae RECO nen ERE debat 9 3 0 Specifications eere 11 Electrical Specifications Physical Sp cifications cte td ette Cete ecu 4 0 Practical Application and Use 13 Example Application ieri rire terreri A 13 5 0 Operation 4 terrent aaaea aranean 17 Appendix A Warranty eeeeeeeeeeeeeeneeene nennen nnn 19 Appendix B EC Declaration of Conformity 21 This page intentionally left blank Notes Cautions and Warnings 3 Note Denotes helpful information intended to provide tips for better use of the product Caution Denotes a hazard Failure to follow instructions could result in minor personal injury and or property damage Included text gives proper procedures Warning Denotes a hazard Failure to follow instructions could result in SEVERE personal injury and or property damage Included text gives proper procedures 3 See the ETS Lindgren Product Information Bulletin for safety regulatory and other product marking information This page intentionally left blank vi 1 0 Introduction The HI 3624A ELF Magnetic Field Meter is designed to measure the flux density of magnetic fields in the frequency rang
10. icity within the home 14 A phenomenon which has recently received some attention in regard to residential magnetic fields is the flow of earth currents via plumbing lines or telephone cables buried beneath the home In some cases it has been noted that 60 Hz magnetic fields exist within a home even when the home is not using any electrical power the circuit breakers have all been turned off at the main electrical service box of the home This observation has in some cases been related to the flow of currents beneath the home on pipes or cables It is not unusual for currents related to other neighbors use of electricity to flow back to the electrical supply via low resistance paths formed by metal plumbing pipes or wires used for telephones as opposed to the electrical system neutral wire In Such cases it is possible to measure magnetic flux densities within the home without any apparent reason if the power to the home has been shut off 15 This page intentionally left blank 16 5 0 Operation Before placing into operation follow the safety CAUTION information in the ETS Lindgren Product Information Bulletin included with your shipment The ELF magnetic field sensor must be plugged into the HI 3624A meter case for proper operation it makes no difference whether the sensor is plugged in before or after the meter is turned on The main switch turns on the instrument and selects one of five ranges for measurement
11. izes ETS Lindgren L P to affix the CE mark to the indicated product CE marks placed on these products will be distinct and visible Other marks or inscriptions kable to be mistaken with the CE mark will not be affixed to these products ETS Lindgren L P has ensured that technical documentation shall remain available on premises for inspection and validation purposes for a period ending at least 10 years after the last product has been manufactured This page intentionally left blank 22
12. sidential magnetic fields as well as high level fields found near high current carrying conductors or electrical machinery Standard Configuration e Meter e Probe Manual ETS Lindgren Product Information Bulletin See the ETS Lindgren Product Information Bulletin included with your shipment for the following Warranty information Safety regulatory and other product marking information e Steps to receive your shipment e Steps to return a component for service ETS Lindgren calibration service ETS Lindgren contact information 2 0 Maintenance Before performing any maintenance follow CAUTION the safety information in the ETS Lindgren Product Information Bulletin included with your shipment Maintenance of the HI 36244A is limited to external components such as cables or connectors WARRANTY 7 If you have any questions concerning maintenance contact ETS Lindgren Customer Service Battery Replacement Two 9 volt alkaline batteries power the HI 3624A ELF Magnetic Field Meter To replace the batteries remove the eight screws located on the back of the meter pull the panel away from the chassis and unplug the battery connectors Install the new batteries and reverse the proceeding steps to reassemble the meter Annual Calibration See the Product Information Bulletin included with your shipment for information on ETS Lindgren calibration services Service Procedures
13. urrents flowing within motors or heating elements Logical choices would include the location of beds for example since this is a location of extended occupancy In characterizing the magnetic fields near obvious sources such as appliances it is often helpful to measure and record the flux density value at intervals of a few inches or centimeters beginning near the surface of the device These data will help provide a perspective on the spatial extent of the elevated field levels and the significance of the levels relative to other values determined elsewhere within the home Field measurements should take into account the likelihood that individuals may have access to areas where measurements are contemplated Because 60 Hz magnetic fields produced by the use of electricity within the home are dependent on the magnitude of current flowing within wires or the operation of appliances flux densities will be seen to vary with time being greater when more electrical power is being used For example when heating or air conditioning systems turn on or the compressor within a refrigerator cycles on the flux density will increase Measurements must take this condition into account and it is recommended that when taking measurements in a room the meter be watched for a period of time to observe for fluctuations in the indicated value of flux density After some experience it may be possible to relate the observed fluctuations to various uses of electr
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