Deep search, land and underwater, target-id metal detector (44 pages)
Summary of Contents for Fisher Research Labs Pro-Arc
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Professional Metal Detector for the Archaeologist USER’S MANUAL...
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PRO-ARC is a professional-grade metal detector, designed specifically for the Archaeological professional. It comes in a heavy duty travel case and includes everything you will need on the dig site. The best technology from the oldest company in the business, the PRO-ARC, by Fisher ® PRODUCT FEATURES •...
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• Pin flags and Rite-in-Rain notebook • Headphones • Made in the USA If you have any questions, or need assistance with your metal detector, Call 1-915-225-0333, and ask for Fisher Hobby Technical Service Copyright Fisher Research Labs, Inc., 2012...
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Specifications Mechanical: S-rod with electronics housing mounted on handgrip, 3-piece breakdown, batteries under elbow, 2-way armrest adjustment - forward/backward & around forearm. Searchcoil: 11” (28 cm) open-frame elliptical double-D, waterproof. Batteries: 4 AA, alkaline (included).
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Basic Sensitivity: 6 x 10 9 root Hertz (detectivity) Lag Coefficient: 78 milliseconds Reactive Overload: Approximately 10,000 micro-cgs units (volume susceptibility) 40,000 micro-cgs units with sensitivity < 30. Resistive Overload: Approximately 1,200 micro-cgs units (volume susceptibility) 4,800 micro-cgs units with sensitivity <...
Turn the knob, located under the armrest, fully clockwise. This turns the machine on and sets audio volume to maximum. When first turned on, the PRO-ARC starts out in the Discrimination Mode, with: Sensitivity preset to 60 Discrimination Level preset to 10...
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Quick Start (continued) Rotate the Settings knob to the left (counterclockwise), Reduce the sensitivity setting until the false signals go away. After 7 seconds, the machine will exit the menu and return to normal operation.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Assembly Remove all components from box. Attach searchcoil to lower rod by lining up the holes. Push coil knob through hole and tighten knob gently. You will tighten up the coil knob later.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Assembly (continued) Tighten knurled cap nut by hand to secure cable connection to housing. Use minimal finger pressure to start thread. Do not force threads. Nut may not completely cover all threads when fully engaged.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Assembly (continued) Biaxial Knurled Searchoil Searchcoil knob Cable...
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Settings Switch 2-Way Menu Adjustable Button Armrest Hand-grip Release Clip Headphone Jack Dual-function Battery Trigger Compartment switch S-Rod On/Off & Volume Switch...
Expect 40 hours of service in the field with one set of alkaline batteries. A rechargeable battery kit is included with your PRO-ARC. Rechargeable batteries will usually deliver over 25 hours of service without recharging, but when they start running low, they die suddenly with little warning.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Mechanicals (continued) IMPORTANT: To avoid stressing the battery spring connection, install the batteries using this technique: 1. Position the bottom (negative) side of the battery on top of the spring. 2. Do not install the top of the battery into the compartment yet.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Mechanicals (continued) ARMREST The armrest WIDTH and POSITION are both adjustable. Armrest Width: The sides of the armrest can be bent inward and outward. To best stabilize the detector to your arm and body movement, squeeze the sides of the armrest around your forearm.
The locking collars must be rotated a full 270° to reach the locking position. HEADPHONES The PRO-ARC is equipped with a standard 1/4-inch stereo headphone jack at the rear of the unit, located under the elbow as you hold the detector for use. Any headphone with a stereo plug should work;...
Target ID to facilitate searches for specific types of artifacts. The PRO-ARC operates at 13 kHz for good sensitivity to both high and low conductive artifacts such as gold and coins. The PRO-ARC comes with an 11-inch elliptical Bi-Axial searchcoil for maximum detection depth in mineralized soils.
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Jorge Saad and Mark Krieger. The mechanical design was a collaboration among David Johnson, Brad Fulghum, John Griffin and Tom Walsh. MECHANICAL ENGINEERING While the PRO-ARC is robustly engineered for outdoor use, it is not indestructible and it is not waterproof. RESET function The PRO-ARC's microprocessor saves all settings which you input, even after the power is turned off.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Controls DUAL FUNCTION ON-OFF & VOLUME MENU BUTTON Settings Knob (Under the elbow) Knob Menu Toggle From This knob turns the Access bP or CL Process machine on or off, and controls speaker volume and headphone volume.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Controls (continued) The PRO-ARC has two controls on the front panel, MENU and SETTINGS. MENU Pushbutton (Red button on right of the front panel) Push the MENU button to: Step through the menu selections on the display. With each push of the button, the next menu selection will be highlighted.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Controls (continued) The dE process will only be engaged while the button is depressed. Releasing the button will return you to the process you were operating in. When using any processes other than bP or CL, pressing-and-holding the button will have no affect.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Controls (continued) TRIGGER SWITCH (Under the display in front of your hand) While the trigger is pulled back, metal objects are temporarily detected without the need for searchcoil motion. This aids in pinpointing the exact location of objects which were found while searching in the Discrimination or motion All Metal modes.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting The Menu System The entire menu is printed on the LCD display. The display highlights the mode and settings which are in use. There are three search modes, Static All Metal, Motion All Metal and Discrimination. To change between an All Metal Mode and Discrimination Mode, the top line of the menu system must be highlighted.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting The Menu System (continued) To change a setting, rotate the knob. To increase a value, rotate to the right (clockwise) To decrease a value, rotate to the left (counterclockwise) If you select a function and do not make a...
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Ground Balancing What is Ground Balancing? All soils contain minerals. Signals from ground minerals are often tens or hundreds of times as strong as the signal from a buried metal object. The magnetism of iron minerals, found in nearly all soils, causes one type of interfering signal.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Ground Balancing (continued) can be accomplished automatically with the detector's internal computer by pushing the Trigger Switch forward, or manually in the All Metal menu. The ground balance setting carries through into all operating modes. In Discrimination Mode, the ground signal is generally inaudible unless the discrimination setting is 0.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Ground Balancing (continued) MANUAL GROUND BALANCING In most situations, it is preferable to push the trigger switch to activate FASTGRAB™ automatic ground balancing. Generally, it is best to first let the computer automatically cancel interference from ground minerals.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Ground Balancing (continued) 0 - 10 Wet salt and alkali 5 - 25 Metallic iron. Very few soils in this range. You are probably over metal. 26-39 Very few soils in this range -- occasionally some...
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Ground Balancing (continued) 3. Turn the SETTINGS KNOB to adjust the setting. The goal is to eliminate the sound as the coil is being pumped over the ground. In some soils, the sound is not completely eliminated.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Ground Balancing (continued) that when the searchcoil is lowered to the ground in PinPoint, Stat or Motion All Metal Mode, the sound will get louder as the searchcoil approaches the ground. The sound will grow quieter as the searchcoil is raised.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Motion All Metal Mode The Motion All Metal Mode is more sensitive and offers better feel than the Discrimination Mode, and is used to find all metal objects present in the ground. The searchcoil must be in motion for objects to be detected.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Motion All Metal Mode (continued) will usually be too noisy (wobbly and erratic sound) if the sensitivity is set too high. At settings above 90, the internal circuit noise of the machine will probably be audible.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Static All Metal Mode This mode is useful for finding large, deep objects, i.e. larger than a coin and deeper than 12 inches (30cm). STATIC functions similar to PinPoint but occupies a different position on the user interface.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Static All Metal Mode (continued) If the background chatter is too annoying, or the ground noise is so high that it impedes operation, reduce sensitivity. Such a downward adjustment in sensitivity improves depth detection as you can now hear weak signals better.
Discrimination incurs some loss of sensitivity to small or deep objects. This mode can be used if you wish to be selective in what you wish to search for. The PRO-ARC discrimination system is much improved over conventional discrimination systems. In older systems, the apparent sensitivity decreases as discrimination level increases.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) The sensitivity system has two stages, 1-29 (low gain), and 30-99 (high gain). As you lower sensitivity and cross the transition from 30 to 29, you may notice the background noise increase.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) be stored as the discrimination value. • All targets up to and including the value selected, will be eliminated from detection, unless notched-in. 5. A slash will appear over the target words being eliminated. Notice that two slashes can appear over each word.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) 2. Press MENU button 4 times to move down to the NOTCH feature -then rotate the SETTINGS knob to the right until the number 40 appears. -then press MENU again to accept this notch value.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) The following are characteristics of NOTCH programming: • As you rotate the knob to enter a notch range, the target indicator block at the top edge of the screen illuminates to show you the range you are in.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) Here are some examples of NOTCH used in conjunction with DISC LEVEL If Discrimination Level is set at 60, and you set the top-of-foil (21-25) notch between 21 and 25, then: top-of-foil range (21-25) is NOTCHED-IN (i.e.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) 1F: MEDIUM-TO-HIGH PITCH TONE varying in proportion to target signal strength. Large shallow objects will produce a squeal. The variable audio pitch provides you more information about the detected object, but some people find the sound on strong signals too annoying.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) Process Number (Process #) This menu selection offers the user a choice among several different methods of audio discrimination to accommodate a variety of search conditions and personal preferences.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Discrimination Mode (continued) PF: For use in plowed fields. Some users may prefer this process for hunting in irregular ground, especially plowed fields. PF: BOOST PROCESS This process is an enhanced sensitivity version of the dE (default) process. It is...
Target ID and audible response. By making the audio and visual systems independent, the PRO-ARC allows each system to do what it does best. The audio is optimized for quick response and target feel, whereas the visual system provides the best...
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting PinPoint Feature After a buried target has been located using the All Metal or Discrimination modes, you want to pinpoint the exact location of the target in order to facilitate its recovery. Accurate target pinpointing will minimize digging.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting PinPoint Feature (continued) How to Pinpoint Position the searchcoil an inch or two (2.5-5cm) above the ground, and to the side of the target. Then pull the trigger. Now move the searchcoil slowly across the target, and the sound will indicate the target's location.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting LCD Visual Display In normal operation, when the searchcoil passes over a metal object, the electrical signature (2-digit ID) of the metal object is displayed on the numeric display for 4 seconds, unless superceded by another detected object.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting LCD Visual Display (continued) Aluminum screwcap 60 - 70 Zinc penny (dated after 1982) Typically 60 Aluminum soda pop can Most often 63-69, but can vary widely Copper penny, clad dime Typically 70 U.S.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting LCD Visual Display (continued) Most gold jewelry is small, and will tend to read in the 16-55 range. Silver jewelry usually has more metal in it and therefore tends to produce higher readings.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting LCD Visual Display (continued) Target ID is accurate. If 3 or fewer segments are displayed, the confidence is very low. Junk targets tend to produce lower confidence indications than coin targets of similar electrical conductivity.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting LCD Visual Display (continued) BATTERY CONDITION INDICATOR Fresh alkaline batteries will illuminate all three bars. When no bars are displayed and the batteries are about to go dead, the BATT legend will start flashing. The detector should operate for an additional 30 minutes from the time the BATT legend starts flashing.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting LCD Visual Display (continued) conditions. Raise the coil until the message disappears; the siren sound will also stop. Resume normal detection. The message RAISE COIL only appears when using the bc process, accessed through the PROCESS # menu selection.
If you suspect electrical interference, you may change the PRO-ARC's operating frequency. This is a trial-and-error method to try to find a frequency different from the suspected source.
The LCD will display the frequency, from F1 to F7. F1 is the lowest frequency, F4 is the default frequency. The PRO-ARC does not retain changes in the frequency setting when powered off. See the Search Techniques section of this manual for more information on electrical...
Capabilities and Limitations DEPTH The PRO-ARC can detect U.S. coins to a depth of up to 15-16 inches (37-40cm) under good conditions. Large objects (55 gallon drums, manhole covers, etc.) can be detected to a depth of up to several feet (1-2 meters).
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8 inches. REQUIREMENT FOR MOTION: PINPOINT FEATURE As with other modern metal detectors, the PRO-ARC's searchcoil must be kept in motion in order to both detect and identify targets. The All Metal modes are more forgiving of sweep speed variation than is the Discrimination Mode.
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Discrimination refers to a metal detector's ability to ignore metal objects in selected categories, especially iron and aluminum. The PRO-ARC offers a wide variety of discrimination features which you can select according to the search conditions and your personal preference.
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In order to most accurately verify a detected target with most other metal detectors, users will narrow their sweep and loiter over the top of the target. The PRO-ARC is different. The PRO- ARC's quick response and advanced signal sampling system produces the most accurate Target IDs with deliberate (shoulder width) sweeps all the way across the target, even if there are other targets nearby.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Capabilities and Limitations (continued) STEEL BOTTLE CAPS & FLAT IRON TRASH Modern motion-type Target ID metal detectors usually have difficulty consistently identifying steel bottle caps and other flat iron trash objects. Double-D searchcoils also have a reputation for having difficulty distinguishing steel bottle caps from coins, and for being unable to eliminate steel bottle caps from detection.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Capabilities and Limitations (continued) away from the searchcoil will usually produce readings that bounce around from medium to low numbers. 4. SWEEP THE REAR OF THE SEARCHCOIL OVER THE CENTER OF THE TARGET, OR SWEEP RAPIDLY.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques Sweeping Searchcoil (this does not apply to Pinpointing with the trigger switch) Keep the searchcoil in motion to detect targets. Sweep the searchcoil parallel to the ground; do not lift the searchcoil at the end of the sweep.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) the searchcoil until the overload warning disappears, and sweep at this increased height. Large Targets If an overload warning is not confined to a small spot, you are probably overloading on a large object, for example, a large iron pipe, reinforcing steel in concrete, or buried sheet metal.
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Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) The PRO-ARC's other processes have a reputation for lightning-fast response over targets, with the result that the duration of the sound over a good target can be very short, especially in a trashy area.
If you are new to the PRO-ARC, toggling back to default process from bP or CL can serve as a learning tool to understand the different response characteristics of the different processes.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) and the audio pitch is highest. If the sound is loud over a wide area, the buried object is large. Use the PinPoint feature to trace an outline of such large objects.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) Objects which are ring-shaped, or flat and round like coins, tend to give a narrower, crisper response than objects of similar size with irregular shapes. The easiest way to demonstrate this is with an aluminum screwcap from a soda bottle.
ID numbers higher than would be obtained in an air test. This tendency is connected with the PRO-ARC's enhanced see-through ability - that is, the ability to find valuable targets in an area where there is a lot of iron trash.
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If the interference is from a communications or broadcast transmitting antenna, reducing the sensitivity is usually your only recourse. The PRO-ARC allows you to shift operating frequencies to avoid electrical interference. See the Frequency Shifting section for information about this technique.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) include deeply buried objects, little bits and pieces of rusty iron and corroded foil. These items can be detected, but are difficult to pinpoint due to their depth and small size. When you dig and find nothing, it may seem like the machine is beeping at nothing even though there is actually something there.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) In spots where there has been intense fire, such as a campfire site or where a stump was burned during land clearing, the soil minerals may be altered by oxidation so that their ground balance setting is lower than that of the surrounding soil.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) Negative hot rocks (also called cold rocks) are usually magnetite or contain magnetite, and give a negative response because their ground balance value is a higher number than the soil they are found in. They tend to be dark in color, usually black, and usually heavy.
In this case you may do better if you reduce the Sensitivity setting. Tips on Ground Balancing When the PRO-ARC first turns on, the Ground Balance setting is preset to 90. This will give a positive response on nearly all soils. If you search in the Discrimination Mode, you will probably not have to balance to the ground.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) present. Locate what seems to be a clear area and then Ground Balance. Ground Balancing may be done automatically by pushing the trigger, or manually if you are in All Metal Mode.
SHALLOW WATER HUNTING All Fisher Research Labs searchcoils are waterproof, allowing you to search in shallow water about two feet deep. If searching around water, be careful not to get the electronics housing wet.
SALT WATER HUNTING Salt water is highly conductive, and produces a strong signal which is like that of metal. The PRO-ARC is not specifically designed for high performance in salt water, but can be used in this environment. If you desire to search in or over salt water, the following measures will usually be sufficient to silence the salt water response while retaining acceptable sensitivity: Set the sensitivity in both modes to less than 30.
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PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting Search Techniques (continued) information to the user in the form of a visual display or audio tones. Most modern metal detectors perform many of these tasks in software running on an internal microcomputer.
PRO-ARC Comprehensive Operating Manual & Guide to Metal Detecting 5-Year Limited Warranty The PRO-ARC metal detector is warranted against defects in materials and workmanship under normal use for five years from the date of purchase to the original owner. Damage due to neglect, accidental damage or misuse of this product is not covered under this warranty.
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All rights reserved, including the right to reproduce this book, or parts thereof, in any form. Published by Fisher Research Labs, Inc. Fisher¨ is a registered trademark of Fisher Research Labs, Inc. www.fisherlab.com 1465-H Henry Brennan Dr., El Paso, TX 79936 • (915) 225-0333...
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Fisher Arm Strap (not shown) ® 100% white cotton with Fisher Logo. Sizes -S, M, LG, XL & XXL Specially made to fit the arm cuff of your PRO-ARC. - ARMSTRAP75 - FTSHIRT (specify size) FOR COMPLETE DETAILS VISIT WWW.FISHERLAB.COM • 1-800-685-5050 MPROARC Rev.2...
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