Electromagnetic Detectors >> MD 5008


 MD 5008

Made In U.S.A

Please read before using this equipment

Metal Detector


GPX 4500 Metal Detector is designed by advanced international technique, and is made of high quality , It is quite popular for its excellent features, goods detection depth, strong pinpoint, great discemment and easy operation.

It is mainly used to detect and distinguish metal buried in the earth
• Checking metal in material fuel , foods , ect ;
• Checking metal in post package , baggage ect ;
• Detecting underground pipe ;
• Searching for buried gold silver jewelry in archeology and mining , ect .


Zeroing Button
The button under view meter is called “Zeroing button” We often need to press and release it during tuning and working process. By pressing and releasing it, detector’s memory circuit would automatically record work state. Forgetting to press and release zeroing button would affect detection depth and normal work.

Operation Mode Switch
1. Power On/Off Switch
Turn it On, LED is light turn it off after finishing detection.
2. Operation Mode Switch
There are two modes: One is Ground Balance Mode, the other is Discrimination Mode.
Ground balance mode, detector give sound signal and be able to eliminate mineralization reaction
In discrimination mode, detector is able to distinguish different kinds of metal.


Tune Turn Button
1. Critical Sound Adjuster
It’s function is tuning critical sound: turn it clockwise from left side, signal sound rise little by little when sound is just heard it’ called “critical sound’ . In this position, detector has the highest sensitivity . If critical sound is to loud or isn’t being heard sensitivity is lower.
Before tuning it, it I necessary to press zeroing button irst, and release button after finishing tuning critical sound. During detection, if critical sound is rising , going down or disappearing, press zeroing button until critical sound is back again.

2. Function Adjuster
Function adjuster is used cooperating with operation mode switch it’s scaled with 0-10 in ground balance, detector can Eliminate “mineralization reaction” by tuning this turn button in this mode , detector can distinguish different kinds of metal>

Earphone Socket and External Power Socket
GPX4500 is equipped with digital stereo earphone socket In noisy area and the evening, user can use it.

GPX4500 is equipped with external power socket for additional battery support.
Assembling your detector is easy and requires no special tools. Just follow these steps.

• Turn the stem’s lock nut clockwise until it loosens.

• Lengthen or shorten the stem so when you stand upright with the detector in your hand, the search coil is level with and about 8 inches above the ground with your arm relaxed at your side.

• Turn the stem’s lock nut counterclockwise to lock it in place.

• Unscrew the knob on the search coil and remove the knobs and connector. Insert the stem and align the holes on the search coil bracket and the stem. Push the connector through the holes and tighten the knob

• Wind the search coil cable around the stem , leave enough slack in the cable to let you adjust the search coil when you are hunting on uneven ground >

• Insert the search coil’s plug into the search coil jack on the detector’s control housing. Be sure the pins on the plug align with the holes in the jack..

• The search coil’s plug fits into the connector only one way. Do not forces the plug or you could damage it.

• To disconnect the search coil’s cable from the detector. Grasp the plug and pull on the cable.

7. Loosen the knob at the search coil’s end. Then adjust the search coil to the desired angle. (The search coil should be parallel with the ground) Tighten the search coil from rotating or wobbling.
Caution: Do not over tighten the search coil or use tools such as pliers to tighten it..

Your need 8 pieces of 1.57 batteries to power your detector.
• Use only fresh batteries of the required size and recommended type.

• Do not mix old and new batteries different types of batteries (standard, alkaline, of rechargeable), or rechargeable batteries of different capacities.
1. if the detector is ON, turn into OFF
2. Press the right batter compartment cover’s tab and slide the cover off in the direction of the arrow.
3. Place 4 pieces of 1.57 battery into the battery compartment on top of the ribbon, matching the polarity symbols (+and- )
4. Replace the right battery compartment cover.
5. Press the left battery compartment cover’s tab and slide the cover off in the direction of the arrow.
6. Place 4 pieces of 1.57 batteries into the battery compartment on top of the ribbons, matching the polarity symbols ( + and – ) marked.
7. Replace the left battery compartment cover.
• Always remove old or weak batteries; batteries can leak chemicals that can destroy electronic parts
• If you don’t plan to use the detector for a week or more remove the batteries.
• Disponce of old batteries promptly and properly.

You can extend battery life by using headphones, which require less power than the built –in speakers

Testing the batteries
if the indictor light is dim or dark the detector does not turned on , has weak volume, will not turn properly, has erratic operation, or drafts . replace the batteries.

Adjusting the timer
With mode set to off, use the screwdriver to adjust the alignment control until the pointer less up with 0 on the scale.

Using headphones
You can connect a pair of stereo headphones (not supplied) to the detector, so you can listen to it privately.

Using headphones saving batteries power and makes it easier to identify ubtle in the sounds you hear, for better detection results.

To connect headphones to the detector, insert the headphones 1/8 inch plug into the head phones jack on the side of the control housing.

The detector internal speaker disconnects when you connect headphones.

Listening safely

To protect your hearing, follow these guidelines when you use headphones.

* set ht e volume to the lowest before you begin listening. After you begin listening, adjust the volume to a comfortable level.
Don’t listen at extremely high volume. Extended high volume can lead to permanent hearing loss.

• once you set the volume, don’t increase it. Overtime, your ears adapt to the volume level, so a volume level that doesn’t cause discomfort might still damage your hearing.

Traffic safety

Don’t wear headphones while operating your detector near high traffic areas.

Even though some headphones are designed to let you hear some outside sounds when listening at normal volumes levels. They still can present a traffic hazard.

External power jack

Actual detection operation

First place batteries into compartment, during detection, keep search coil 10 -15 above the earth and move parallel over the earth . don’t rise search coil too high to causing the decrease of detection depth ability.

Ground balance mode:

This mode can eliminate the “mineralization reaction” and has better penetrability. So this mode is mostly selected wherever indoor or outdoor search in this mode, as long as the search coil is moved right over metal target, detector sounds and view meter’s pin-pointer moves no matter what kind of metal id detected.

Follow steps below to adjust it:
2- Rise search coil 70 -80 cm over the earth/
3- Press zeroing button, set critical sound. Then release button.
4- Close search coil 10 – 15 cm above ground, if “critical sound” increases, please rise search coil and press button, turn function adjuster anti-clockwise a little, then relieve button. Close search coil to the ground once more, if sound still increases, try as above again, after tinning a few times whenever search coil is close or far-away from ground, signal sounds keeps steady. This express GROUND BALANCE is ok after such adjusting, “mineralization reaction” is basically eliminated; critical sound doesn’t change with search coils up and down moving, detectors only responds to metal target.
5- If signal sound decreases when closing ground , rise search coil and press zeroing button, turn clockwise function adjuster, then release zeroing button. If sound still decreases, set as above again until sound keeps steady whenever detector is close or far away from ground.
6- Note: before each items as above, you need to press zeroing button first, after finishing each items, release the button.
7- After adjusting as above, you can move search coil slowly along the ground during detection , keep detector in critical sound state. If sound signal rise or fall, press or release zeroing button to get critical sound again when founds view meter will have obvious display.

Discrimination mode

This mode is used for distinguishing ferrous and non-ferrous metal, to select metal target. For not having ground balance function, mineralization reaction is heavy, so users should keep the distance between search coil and ground , move slowly over the ground.
Follow these steps to set it:
1- set mode to discrimination
2- press zeroing button, set critical sound
3- during detection, you can eliminate unneeded target in actual circles.
For example :in an area full of iron nail, iron nails signals will interfere detection, to solve such problem, you can first but a iron nail on the ground and let search coil sweep over it: a) if the sound increase press the button and rotate the function adjuster anti clockwise a little, then relieve zeroing button and try again, B) if sound falls , press button and rotate function adjuster clockwise a little, then relieve button to try, all is ok until sound keep steady when search coil sweep over the iron nail. After adjusting detector will not respond to iron nails and ferrous metal whose size is smaller than the nail , but will respond to all non-ferrous metal and ferrous metal whose size is bigger than the nail.
4- tune function adjuster bellow scale 2 , sound rise when responding bigger non-ferrous metal but fall when responding bigger ferrous metal, tune function adjusters scale over 7 , sound rise when responding bigger ferrous metal but fall when responding bigger non-ferrous metal.
5- If distinguish a sheet of iron phenomenon is peculiar when search coil is close to its edge detector reacts same as responding ferrous metal when close to its centre, detector reacts same as responding.

Detection Example:
In actual detection, user should use detector basing actual circles.
For example: Detect Mine
GPX-4500 is able to be used for detecting mine buried in flat earth, such as natural gold bullion, gold reef, placer gold mine, all kinds of rich mine, etc.
Detect natural gold is the same as detect metal coin detecting in Ground Balance you must pre-set Ground Balance for most gold bullion is buried in terrain high mineralized.
In placer gold mine, gold dust is mixed with sands and large amount of heavy metal mines sediment. Signal caused by this mixture is same as it caused by black metal, but a little weaker than signal caused by pure metal. With GPX-4500, we can also filtrate ore to do this, first fix detector on a non-metal support, then close ore to search coil one by one, estimate metal content in the ore by sounds high or low.
Note: press zeroing button each time after detecting one piece of ore.
To copper, iron, stannous, lead, etc, signal is different because different quality. You can test one standard ore and get reaction, then confirm the distinction between this kind of ore and other common rock .

Care and Maintenance

Cleaning: clean search coil part with waterish towel carefully, coil’ plug should be avoided dampness, or detector will loss detection ability, the plug can be used only after drying in such condition.
Battery: place batteries matching polarity symbols (+ and – ) if you won’t you it for a long time, take out the batteries to avoid putrid ness.
Temperature: The detector should be far away from furnace and other high temperature circumstance.
Brine has strong causticity, detector should be avoided being cauterized by it if brine is dipped in detector . wipe it up by dry towel.
1- If detector work abnormally, or signal sound can not be decreased after being increased, please replace battery.
2- Don’t press zeroing button right over metal, press button over area without metal in detection, don’t press button all the time.
3- If detector can not keep “critical sound”, there is some problems with detector, please send it back to factory for fix.
Main Tech Parameter:

Max detection : 6 Meter
Operation Mode: Ground balance & Distinction
Emitting Signal Frequency : 6.99 – 0.2 KHZ
Audio Signal Frequency: 450 HZ – 10 HZ
Power: .06 W
Power Supply: DC 12 V