HI-3603 VDT/VLF Survey Meter User's Manual Declaration of Conformity ETS-Lindgren, L.P. 1301 Arrow Point Drive Cedar Park, TX 78613 USA Declares that the HOLADAY product described in this instruction manual is in compliance with: EN EMC Directive 86/336/EEC, EN50082-1, EN55011 ETS-Lindgren, L.P. (Formerly Holaday Industries, Inc.
HI-3603 VDT/VLF Survey Meter 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 2005 by ETS-Lindgren L.P. All Rights Reserved.
HI-3603 VDT/VLF Survey Meter REVISION RECORD HI-3603 VDT/VLG Survey Meter Revision A B C D E Description Initial Release New LCD Revised Spec Revised Spec Added CE Label Revised Addresses © ETS-Lindgren, August, 2005 Revision E, Part #H-600042 Date August, 1992 December, 1992 August, 1994 December, 1995 June, 1997 August, 2005 3
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HI-3603 VDT/VLF Survey Meter Table of Contents 1.0 Introduction.............................................................. 7 2.0 Getting Started...................................................... 11 Specifications......................................................................... 11 3.0 Operation ............................................................... 17 Start Up..................................................................................
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HI-3603 VDT/VLF Survey Meter 1.0 INTRODUCTION The HI-3603 VDT/VLF Radiation Measurement System is designed specifically to measure electromagnetic emissions produced by video display terminals (VDT's), computer monitors, television receivers and other devices using cathode-ray tubes (CRT's) for information or data display.
HI-3603 VDT/VLF Survey Meter contributions of S. M. Harvey at the Research Division of Ontario Hydro (Canada) (Harvey, 1982; 1983a; 1983b; 1984a; 1984b; 1985), the HI-3603 VDT/VLF Radiation Measurement System incorporates technology described in a report developed by A. W. Guy, Director of the Bio-electromagnetics Research Laboratory, Center for Bioengineering, at the University of Washington for the National Institutes for Occupational Safety and Health (NIOSH).
HI-3603 VDT/VLF Survey Meter Electric fields are measured through the employment of a displacement current sensor. A displacement current sensor operates on the principle that two parallel conductive flat-plate electrodes, when electrically connected together, will exhibit a displacement current that flows between the two plates when immersed in an electric field. This can be visualized by remembering that the electric field between two such plates must be zero when they are connected together; i.e.
HI-3603 VDT/VLF Survey Meter sensor has been resistively loaded to produce a relatively flat response over the frequency range of interest for VDT emissions and an output that is proportional to the magnitude of the magnetic field. Thus, the HI-3603 is capable of accurately measuring the strength of magnetic fields from all kinds of VDT's, regardless of their frequency of operation. VDT's, because of their circuitry, produce several kinds of electromagnetic emissions.
HI-3603 VDT/VLF Survey Meter 2.0 GETTING STARTED SPECIFICATIONS • Concentric plate displacement current electric field sensor. • 8 inch diameter magnetic field sensing loop • Switch selectable between electric and magnetic fields Sensitivity: • Electric fields - 1 - 1999 V/m • Magnetic fields - 1 - 1999 mA/m Features: • All function and range selection changes are made by use of the membrane switch keypads on the front panel.
HI-3603 VDT/VLF Survey Meter The HI-3603 VDT/VLF Radiation Survey Meter package includes the Readout-Sensor Assembly, batteries, fitted carrying case, and a user manual. Instrument accuracy is derived from a field calibration using a one meter diameter pair of Helmholtz coils for establishing an accurately known magnetic field strength and a transverse electromagnetic (TEM) cell for creating a known electric field strength.
HI-3603 VDT/VLF Survey Meter Figure 2: Typical Frequency Response Figure 2 demonstrates a typical frequency response plot for both electric and magnetic fields for the HI-3603. Note that the bandpass of the HI-3603 is designed to limit response to fields generated by 60 Hz sources and other emissions below approximately 5 kHz. In a similar fashion, high frequency response is controlled to minimize detection of fields above approximately 300 kHz.
HI-3603 VDT/VLF Survey Meter mode of the HI-3603, the frequency response for the principal VDT fly-back circuit emissions will be flat within ± 1 db or better. Subjecting the instrument to electric or magnetic fields with different waveforms but having the same RMS magnitude can assess the effectiveness of the true RMS detector in the HI3603.
HI-3603 VDT/VLF Survey Meter to more rapidly changing fields, however, similar to that which occurs during the VDT flyback period, is quite accurate and suffers less distortion. Use of this output signal for specialized measurements of VDT's is covered in Appendix A. Figure 3: Electric field response of HI-3603 to a 30 kHz sawtooth waveform with a 9:1 symmetry ratio as observed at the preamplifier output jack.
HI-3603 VDT/VLF Survey Meter Figure 4: Magnetic field response of HI-3603 to a 30 kHz saw-tooth waveform with a 9:1 symmetry ratio as observed at the preamplifier out jack. The display shows both the applied field waveform and the preamplifier output waveform superimposed; distortion of the slow part of the saw-tooth ramp is apparent but the rapid flyback transition shows no distortion.
HI-3603 VDT/VLF Survey Meter 3.0 OPERATION NOTE: The HI-3603 is enclosed in a rugged aluminum extruded case for protection of its internal circuitry. Because of the nature of its intended use, the field sensor extends from the readout module. The structure of the sensor is a multilayered printed circuit board. It is well secured internally to the aluminum case and has a tough polyester covering but is exposed to greater potential for physical damage because of its size and location.
HI-3603 VDT/VLF Survey Meter The digital display response is digitally filtered for increased ease of operation. This smooths the response to rapidly changing fields. In some measurement situations, however, it may be helpful to increase the response of the digital display, ie. reduce the response time. This is done when the instrument is turned on. Refer to KEYPAD MATRIX in this section, and the operation of the E/H keypad for details.
HI-3603 VDT/VLF Survey Meter condition is allowed to drop below that necessary for proper operation, the display will go blank. DIGITAL DISPLAY The HI-3603 uses a custom Liquid Crystal Display to provide information on instrument setting as well as the variables being measured. Refer to Figure 6 for the display outline. Figure 6: Display Outline ELECTRIC FIELD/MAGNETIC FIELD MODE SELECTION The HI-3603 measures both electric (E) and magnetic (H) fields.
HI-3603 VDT/VLF Survey Meter KEYPAD MATRIX For maximum flexibility in operation, the HI-3603 has a keyboard matrix for the upper three keypads on the membrane switch panel. The function of each of the three keys can be changed depending on the location of the CURSOR block in the LCD display. The cursor block is a dark rectangle located at the bottom edge of the LCD display. On turn on, the cursor is located above the leftmost of the three columns of functions on the control panel.
HI-3603 VDT/VLF Survey Meter SCALE - The SCALE keypad changes the fixed ranges or scales of the instrument. When turned on, the HI-3603 is in the AUTO RANGE mode. The unit determines the correct range within the current mode (E or H field) according to the detected field level. As the field being measured increases or decreases, the range is automatically selected for best resolution and accuracy. In some situations, it may be helpful to fix the scale of the instrument.
HI-3603 VDT/VLF Survey Meter E/H - Pressing the E/H keypad toggles the operation mode between Electric and Magnetic field indications. The current measurement units are displayed to the right of the reading on the LCD. The E/H keypad is also used to adjust the display response time. This is done just after the meter is turned on. During the self-test routine, the display will show all segments lit. When all the segments are lit, press and hold the MODE SELECT keypad to enter the setup mode.
HI-3603 VDT/VLF Survey Meter DISP 3/4 - Pressing the DISP pad will shift the display from 4 to 3 digits and back again. In some situations where the measured field is fluctuating, the three digit display will make reading the instrument easier. CLEAR DATA - Clears values stored in the data logging memory. Pressing this keypad will clear all data stored in the data logging memory. When the keypad is pressed a flashing clr is indicated. Holding the keypad until 000 is shown will clear the memory.
HI-3603 VDT/VLF Survey Meter When the displayed value is below 5% of the current full scale, the arrow at the left end of the BarGraph display will indicate. When the "Below Range" arrow is indicating, the accuracy of the reading may not be within the specified tolerance. When possible, the scale should be changed to permit a normal field strength reading without the "Below Range" indication. If the displayed value is too high, the " Over Range" arrow at the right end of the BarGraph, will indicate.
HI-3603 VDT/VLF Survey Meter horizontal and vertical deflection systems; (4) broadband RF fields caused by the digital electronic circuits which are associated with character generation (Roy, et. al, 1983). MODULATED DC FIELDS To accelerate the electron beam toward the screen, a high DC voltage is used.
HI-3603 VDT/VLF Survey Meter 60/50 HZ FIELDS These fields are caused primarily by the current flowing in the vertical deflection coil and are nearly symmetrical around the coil. It is produced by the same mechanism that produces the DC field; the charge on the VDT screen that produces the DC field is actually not constant but builds up and decays by a small amount each time the display is scanned by the electron beam.
HI-3603 VDT/VLF Survey Meter harmonics. See Figure 2 for an illustration of the frequency response of the HI-3603. In addition to the horizontal sweep-frequency circuit, there is a vertical deflection circuit that is used to deflect the electron beam down the CRT screen and in so doing produce characters. The vertical sweep frequency is approximately 60 Hz.
HI-3603 VDT/VLF Survey Meter ELECTRIC AND MAGNETIC FIELD LINES Figures 7 and 8 illustrate how the electric and magnetic field lines are typically directed near a VDT. There are significant differences in the perturbation effect caused by the presence of the operator relative to electric and magnetic fields. Because of capacitive coupling between the operator and ground, the operator tends to bring the existing ground potential up nearer the VDT and emerging electric field lines terminate on the operator.
HI-3603 VDT/VLF Survey Meter Figure 8: Magnetic field emissions from the VDT are unperturbed by the presence of the operator. Because of the perturbing effect of the operator's body on the electric field close to the VDT, it is apparent that the evaluation of electric field emissions will be very dependent on proximity of the operator and/or other nearby objects.
HI-3603 VDT/VLF Survey Meter CHARACTERIZING VDT EMISSIONS AND OPERATOR EXPOSURE In the section labeled VDT Characteristics above, the effect of the presence of the operator on field emissions was described. Because of this perturbing influence on measured electric field strength values near VDT's, it is important to distinguish between assessments of operator exposure and basic emission characteristics of VDT's. Relative to electric fields, these two properties are not the same.
HI-3603 VDT/VLF Survey Meter has been recommended (Diffrient et al., 1981). Nevertheless, because the value of 30 cm has been so often reported in the literature, measurements should at least include this distance among possible others. VDT emission data reported in the literature show that in most instances a fixed screen condition has been used to promote more repeatable measurements.
HI-3603 VDT/VLF Survey Meter Measurements of the magnetic field strength are considerably less difficult since the presence of the human body does not perturb the magnetic field. In this case, the instrument is generally held so that the sensor paddle is in an orientation that yields the maximum reading on the LCD screen. For most VDT's this will be in a horizontal position with the paddle facing upward with the center of the paddle located at a distance of 30 cm from the front of the VDT screen.
HI-3603 VDT/VLF Survey Meter area of the sensing loop. As the distance between the probe and the screen is decreased, greater error will exist in the indicated value of magnetic field strength. This spatial averaging error diminishes rapidly with distance from the VDT since the field rapidly becomes more uniform. Figure 10: Typical VDT RMS electric and magnetic field strength variation with distance from the screen.
HI-3603 VDT/VLF Survey Meter CHARACTERIZING OPERATOR EXPOSURE Measuring operator exposure to VDT electric field emissions requires that the HI-3603 be supported with a non-conductive holding device. This is to reduce the influence of the surveyor on the measure of fields incident on the VDT operator.
HI-3603 VDT/VLF Survey Meter process in conjunction with the HI-3616 Fiber Optic Remote Control. The HI-3616 is supplied with a length of non-conductive fiber optic cable suitable for connecting the output of the HI-3603 to the receiver unit. It is difficult to relate the many different exposure phenomena that can occur with VDT operators.
HI-3603 VDT/VLF Survey Meter USING THE MAX HOLD FEATURE In some instances it may be useful to perform area surveys for identifying locations of elevated exposure and determining the maximum field strength in a given area (for example an entire office, series of offices or region within a single office). Such area surveys are simply accomplished by making use of the MAX HOLD feature on the HI-3603. First, locate an area at least 3-4 meters away from any VDT's. Next, press the MAX HOLD keypad and release.
HI-3603 VDT/VLF Survey Meter are generally healthier, and possible exposure to potentially hazardous physical agents is usually under much better control. For example, employers can inform workers of situations which should be avoided; this is not the case for the general population as a whole. Regardless of these considerations, it is informative to examine some of the recommended exposure guides that apply to different organizations and/or countries.
HI-3603 VDT/VLF Survey Meter Standard/Reference ACGIH IEEE C95.1-1991 IRPA (gen. pop. 24 hr.) Swedish 2 Guidelines Frequency (kHz) 0 - 0.1 0.1 - 4 4 - 30 3 - 100 E (V/m) RMS 25000 1 2500/f 625 614 H (gauss) RMS --1 0.6/f --2.05 50/60 (Hz) 5000 1.0 0.005 - 2 25 0.0025 2 - 400 2.5 0.00025 UK 750 Hz 2,000 1.25 (1986) (occ) 50 kHz UK 750 Hz 800 0.05 (1986) (public) 50 kHz USSR 0.03 - 0.3 25 --(public) (Slesin, 1985) (1) Frequency in kHz (2) These guidelines are not based on biological effects.
HI-3603 VDT/VLF Survey Meter frequency counter to this jack allows immediate measurement of the flyback frequency of a VDT. Figure 12 illustrates the use of a portable digital multimeter (DVM) capable of measuring frequency to observe the flyback frequency of a VDT. To perform this measurement, an analog signal sufficient to drive some frequency counters may require that the HI-3603 be placed relatively close to the surface of the VDT.
HI-3603 VDT/VLF Survey Meter The measurement procedure consists of using the oscilloscope to determine (1) the peak-to-peak magnitude of the magnetic field strength and (2) the time for the magnetic field to go through its most rapid transition (flyback time). Figure 13 is an oscilloscope photograph showing an actual measured waveform of the magnetic field near the screen of an operating VDT.
HI-3603 VDT/VLF Survey Meter Figure 13: Monitored magnetic field waveform as observed with an oscilloscope connected to the preamplifier output jack. Each verticle division is equal to 100 mA/m peak-topeak. Because of the electronic method of broadbanding the magnetic sensing loop in the HI-3603, there is some distortion of the measured magnetic field waveform for lower frequency components. However, for typically encountered CRT retrace times, this distortion of the waveform is negligible.
HI-3603 VDT/VLF Survey Meter Determining the RMS time derivative of the magnetic field strength is accomplished by simply dividing the indicated RMS magnetic field strength by the shortest transition time obtained from the oscilloscope measurement procedure. The waveform of the electric field obtained from the same VDT is shown for comparison in Figure 14. Figure 14: Monitored electric field waveform of same VDT as used in Figure 13 observed with an oscilloscope connected to the preamplifier output jack.
HI-3603 VDT/VLF Survey Meter 4.0 MAINTENANCE This section explains which maintenance tasks performed by the user. It also provides information replacement and optional parts. If you have any concerning probe maintenance, consult ETS-Lindgren Service. can be regarding questions Customer BATTERY REPLACEMENT When the battery symbol lights to indicate low battery voltage, replace both batteries.
HI-3603 VDT/VLF Survey Meter Step 2. Briefly describe the problem in writing. Give details regarding the observed symptom(s) or error codes, and whether the problem is constant or intermittent in nature. Please include the date(s), the service representative you spoke with, and the nature of the conversation. Include the serial number of the item being returned. Step 3. Package the system or component carefully. Use the original packing boxes and materials, if possible.
HI-3603 VDT/VLF Survey Meter 5.0 WARRANTY POLICY FOR ELECTROMAGNETIC ISOTROPIC FIELD MONITORING COMPONENTS SCOPE AND DURATION OF WARRANTIES Seller warrants to Buyer that the Holaday Brand Products to be delivered hereunder will be (1) free from defects in material, manufacturing workmanship, and title, and (2) conform to the Seller’s applicable product descriptions and specifications, if any, contained in or attached to Seller’s quotation.
HI-3603 VDT/VLF Survey Meter No claims for shortages will be allowed unless shortages are reported to Seller in writing within ten (10) days after delivery. No other claims against Seller will be allowed unless asserted in writing within thirty (30) days after delivery (or assembly if the products are to be assembled by Seller) or, in the case of alleged breach of warranty, within the applicable warranty period.
HI-3603 VDT/VLF Survey Meter disturbances, war, riot, or any other causes beyond the reasonable control of Seller. This warranty does not cover batteries or any item that is designed to be consumable. Seller does not warranty products of others which are not included in Seller’s published price lists for shielding products and systems supplies and accessories.
HI-3603 VDT/VLF Survey Meter RESULT OF, THE SALE, DELIVERY, NON-DELIVERY, SERVICING, ASSEMBLING, USE OR LOSS OF USE OF THE PRODUCTS OR ANY PART THEREOF, OR FOR ANY CHARGES OR EXPENSES OF ANY NATURE INCURRED WITHOUT SELLER’S WRITTEN CONSENT DESPITE ANY NEGLIGENCE ON BEHALF OF THE SELLER. IN NO EVENT SHALL SELLER’S LIABILITIES UNDER ANY CLAIM MADE BY BUYER EXCEED THE PURCHASE PRICE OF THE PRODUCT IN RESPECT OF WHICH DAMAGES ARE CLAIMED.
HI-3603 VDT/VLF Survey Meter 6.0 APPENDIX A: USING THE HI-3616 FIBER OPTIC REMOTE CONTROL Electric Field measurements with the HI-3603 VDT Radiation Survey Meter often require that the instrument user be isolated from the instrument to avoid perturbation of the ambient field. This is especially so in the case of the electric field component. In other situations, the meter may need to be oriented such that it is difficult to observe the Liquid Crystal Display (LCD) on the front of the meter.
HI-3603 VDT/VLF Survey Meter battery condition of the HI-3603. The HI-3616 battery life is significantly longer than that of the HI-3603; when the display of the HI-3616 no longer responds; replace both batteries. The data link between the HI-3603 and the HI-3616 is a plastic fiber cable. While the fiber optic cable is generally very durable, avoid sharp bends in the cable and avoid placing the cable under tension (do not pull on it).
HI-3603 VDT/VLF Survey Meter 7.0 APPENDIX B: REFERENCES ACGIH (1987). Threshold limit values for chemical substances in the work environment adopted by ACGIH with intended Changes for 1987-88. American Conference of Governmental Industrial Hygienists, Cincinnati. ANSI (1982). Safety levels with respect to human exposure to radiofrequency electromagnetic fields, 300 kHz to 100 GHz. American National Standard C95.1- 1982, American National Standards Institute, September 1. Australia (1985).
HI-3603 VDT/VLF Survey Meter Grandolfo, M. (1986). Occupational exposure limits for radiofrequency and microwave radiation, Applied Industrial Hygiene (1), 2, July. Guy, A. W. (1987). Measurement and analysis of electromagnetic field emissions from 24 video display terminals in American Telephone and Telegraph office Washington, D.C. A report prepared for the National Institutes of Occupational Safety and Health, Cincinnati, March 16. Harvey, S. M. (1982).
HI-3603 VDT/VLF Survey Meter from 100 kHz to 300 GHz. Health Physics (46), 4, pp. 975-984, April. Joyner, K. H., et al. (1984). Electromagnetic emissions from video display terminals (VDTs). Australian Radiation Laboratory report ARL/TR067, December. Mantiply, E. D. (1984). An automated TEM cell calibration system. Report EPA 520/1-84-024, U. S. Environmental Protection Agency, Las Vegas, NV, October [NTIS order number PB85-134377]. Marha, K. and D. Charron (1983).
HI-3603 VDT/VLF Survey Meter Paulsson, L. E., et. al (1984). Stralning fran dataskarmar. Report a 8408, National Institute for Radiation Protection, Stockholm, Sweden, February 4. Petersen, R. C., M. M. Weiss and G. Minneci (1980). Nonionizing electromagnetic radiation associated with videodisplay terminals, Ocular Effects of Non-ionizing Radiation, Vol (229) SPIE (Society of PhotoOptical Instrumentation Engineers), Box 10, Bellingham, Washington 98227 USA, pp. 179-186. Roy, C. R., et. al (1983).
HI-3603 VDT/VLF Survey Meter National Radiological Protection Board, Chilton, Didcot, Oxon, United Kingdom, May. USAF (1987). AFOSH standard 161-9, occupational health, exposure to radiofrequency radiation, Department of the Air Force, October 12. USSR (1976). Occupational safety standards electromagnetic fields of radiofrequency general safety requirements. Official publication GOST 12.1.006-76 of the State Committee on Standards of the Council of Ministers of the USSR, Moscow, January 22. Weiss M. M.
