Importance of Coil in Gold Detectors

Importance of Coil in Gold Detectors

Coils play a very important role in determining the effectivity and performance range of the gold detectors. It is very important that he buyers must choose the coil which is most suitable to their specific purpose or at least possesses the options to alter because if a specific coil is not able to perform in their circumstance, the gold detector would completely go to waste as the required gold items will not be detected or will be ignored. Here are some factors determining the importance of coil in gold detectors:

Coil manufacturing

There are many brands of manufacturers who are only operating in the area if producing coils of various sizes, designs, and technologies for different models of gold detectors. Some examples of coil only manufacturers include Coil Tech, Nugget Finder, Kamra, Nel. etc. Most of the quality coils are manufactured in the United States of America and Australia.

Coil Weight

The if the coil size is less, it will weigh less and if the buyer chooses a bigger coil size, it will weigh the machine down. And that will cause trouble to handle the swinging motions of the gold detector in the field. If the coil technology is varied, it will have no significant impact on the weight of the coil as it is mostly just manipulated by the amount of material in hardware. 

Waterproofing

Waterproofing options are available for coils only, which makes it cost-effective for the gold detectors which are only required to work in the slightly watery ground at the surface level only. But if the buyer requires a fully weatherproof instrument, then it will be available as well.

Options for Upgrade

If the treasure hunter wants to explore a new situation which could not be tested with one particular type of coil, an option is available to change the coil to the required size, called upgrading or downgrading the coil. For that purpose, a new gold detector will not be required but only changing the coil will significantly affect the operations of a gold detector. 

Purpose determines Type of Coil

Your mission and vision about the purpose of gold prospecting must be clear in terms of knowing the type of soil to be explored, the depths required to be covered underground and what would be the size of gold objects to be found, etc. Because this will determine what type and size of the coil are required for the buyer. 

Know Your Coil

  • Swing Speed

As detectors are based on motion-induced technology i is required to continuously swing the coil like a pendulum’s motion. But this speed of swinging can also vary depending upon the model of the gold detector. 

  • Ground Distance

One more important factor to determine the effectivity of the coil is its distance from the ground. In most of the cases, the appropriate distance to be maintained from a coil to the ground is usually about 1 inch. 

  • Discipline

The integrity of the coil is to be maintained on the surface of by ground by making sure sufficient distance is kept such that it does not damage the coil by hitting any obstacles in the way during the swinging etc. 

Sizes in Coils

  1. Small Coils

They start from 5 inches and have a maximum size of 8 inches. In addition they are preferred for high mineralized soil areas. Where possible trashy metallic objects buried underground. The area coverage is negative because of the smaller size. It takes extra time and more swings to cover a limited amount of space.

  1. Medium Coils

These coils lie in the range 8-11 inches in diameter and are the highly recommended type of detector. Coils being in the mid-range affordability and coverage wise. These are work at their best in highly mineralized soils. 

  1. Large Coils

These coils are relatively large including 11 inches, 15 inches, 16 inches, 18 inches, 32 inches, 22 inches, 25 inches, or above. They have relatively low sensitivity and ignore very small objects. Very poor performance in terms of pinpointing, but depth is very good as well as coverage time is fast. Pulse Induction technology, size increases then the effectivity of the coil increases as compared to the ones with VLF technology.   

Angle of Coil

Importance of Coil in Gold Detectors the coil must be parallel to the ground at the angle of 180 degrees . Do not operate the coil’s swinging motions imitating a pendulum, i.e. to and for motions around an axis. If the gold detectors are very close to the ground, then their depth becomes compromised as the ground balance weakens which results in a noisier detector. 

 

treasure Found from Gold Detectors

Guide: Treasure Found from Gold Detectors

Gold detectors from around the world engaged in powerful and rather successful treasure hunting experiences. And news channels are interested to cover the rarest and most interesting stories about such discoveries making it attractive for beginners to seek a deeper interest in this field. Here are some popular and recent examples published as news stories of treasure found from Gold detectors having so much emotional or economic value.

 

A Treasure Hunter found a gold grad ring from 1965

A man who is a chiropractor professionally and a treasure hunter as a hobbyist, found a graduation ring from 1965 in Killarney Lake, Fredericton. The ring had the year engraved on its side and the logo of the high school at the front, a school which was non existent at the time they found the ring. It was 10 karats gold ring of size 7, and the treasure hunter was determined o find the owner. He found the list of 10 female graduates and shortlisted to 4, then reached them out via social networking site. He found the owner of the ring and sent her via mail. Previously, he also found a wallet with 2 Canadian dollars and a student card, whose owner was also satisfactorily found. The treasure hunter finds peace in returning long lost items to their rightful owners.  

 

 https://www.cbc.ca/news/canada/new-brunswick/buried-treasure-hunt-owner-1.5181168

 

Metal Detector Finds the Wedding Ring Lost in the 1970s

A resident of Tenessee Mr. Wesley WHite during an occasional visit to his mother in his senior care facility overheard that one of her fellows lost her wedding ring in her garden 50 years ago and could not find. Her son said she always missed her ring and how she was unable to find it. Mr. White decided he would fetch his gold detector and have a look around the location. He found the ring buried 5 inches under the ground in about 90 minutes and gave it back to her after 50 years. She happily expressed how the ring would be a family heirloom now and thanked Mr. WHie, a retired person and treasure hunting enthusiast for his tremendous efforts.  

 

https://theweek.com/speedreads/849231/tennessee-man-using-metal-detector-finds-wedding-ring-lost-1970s 

 

Man Finds ‘Monster’ $69,000 Gold Nugget in Australia With Metal Detectors

A local treasure hunting hobbyist in Western Australia found a huge gold nugget of about 49 ounces or 1.4 kilograms about 18 inches below the ground. A local shop posted the image of the gold nugget in comparison to a regular-sized coin on their Facebook page. They were then contacted by the BBC news for an elaborate report. The particular town is famous for the gold deposits and many of the people are earning through gold prospecting as their primary mode of income. Others indulge in it as a hobby but also earn sufficiently. 

 

 

Recommended Gold Detectors in 2019

User Guide: Recommended Gold Detectors in 2019

Recommendations are based on your unique purposes of using Gold Detectors, which can be:

 

Long Term or Short Term

First of all the buyer must decide if they are going to buy the detector to use for a short period of time, for example one time, three times, one month, one season or a long time for example a few years to life time. This determines the suage pattern and intensity for gold detectors so it will tell how much to invest in such device. 

Terrestrial or Under Water

Whether the research must be conducted on the ground surface which is completely dry, on some ground where there may or may not be some water, or if the detectors are purely intended to be used under the surface of water. 

For Specific Items or Multipurpose

If the buyer is looking for a specific category of item for example gold nuggets, gold coins, gold relics, statues etc only or if they are interested to look for all or some of these items simultaneously. Because some gold detectors are especially designed to target some type of objects whereas other can be multipurpose with adjustable settings.

For Archaeological Diggings

For diggings of objects buried underneath the ground for a very long time whose shape size or depth can not be actually determined beforehand, some advanced level equipment would be more useful. 

For Geological Research

If the buyer would like to take in depth data about the ground and the metals hidden in the ground for the purpose of adding information to the geological science domain, then the accuracy of a professional level instrument with radar technology would be better alternative and its generic land survey can also be useful determining the texture of earth below the surface. .

At Construction Sites

The personnel at construction sites often require checking and separating the metallic residue from the debris, and where and why the metals are used and how the structure of the building could be made better or improvised. So using such equipment would  be very beneficial. Because the engineers and construction site developers want to analyze the ground they will be building some structures on, and depending of the type, quality and make up of the ground components underneath, the construction project could be effectively modified. 

 

For Professional Treasure Hunters

People who are working with treasure and detection equipment for a long time and know what they are doing with treasure hunting actually have a very good idea about how large profit potential their land has. So that is why they are willing to invest in such quality gold metal detection equipment to get more efficient and precise results. 

 

Electrical Interference in Gold Detectors

Electrical Interference in Gold Detectors

What is Electrical Interference

Electrical Interefernece is the distortion in magnetic field caused by surrounding metallic objects or systems having electricity running through them. If those structures are close enough to get  the magnetism of the gold detectors. Then by absorbing eddy currents they will emit a magnetism of their own which would in return effect the functionality of a gold detector.

Sources of Electrical Interference

Overhead Sources

Large metallic objects or a network of wires or pipes held above the ground will cause significant distortion in detectors because the medium of conduction is air. Includes the metal from wirings, pipings, construction structures, etc.

Underground Sources

The metallic objects buried underground also have a significant impact on creation of electrical interference for the metal detectors and gold detectors. These could include underground wiring systems, underground piping and sewage systems, underground transportation routes etc.

Electrical perimeter fences

The metallic fences built around sensitive buildings for security having harsh edges on top and electrical current flowing through them are also a very important indicator or actor inducing electrical interference. 

Telephone Lines

The network of landline telephone cables laid around below the ground or above can cause electrical interference for the gold detecors as well. 

Heavy Metallic Objects 

Other heavy metallic objects including vehicles for transportation because of their ignition systems, military level communication home based or commercial level computer systems, old CRT-based televisions having comtinous explosions of electrons in the machine, portable cell phones and hand held devices, natural thunderstorms with huge outbursts of electrons, some metal vapor lamps, elaborate military aircraft with electronic warfare countermeasures turned on, daily use electric motors, VLF military communications systems etc.

Built-in Noise from Detectors

Although most of the hardware in the gold detectors is made from non metallic items such as wood and quality plastic, as conduction of electric current is required, it cannot be done without some metallic conductors in the form of the coil, wires attached to the battery and the battery itself. This can cause a built in noise from detectors. 

Wireless Communication technology

Bluetooth, wifi and network connectivity in the modern day cell phone also have the potential to distort the gold detectors via electrical interference and it becomes challenging for the gold detector users because such devices are usually very helpful in the field for connectivity but the mobile phones along with other portable and helpful devices must be kept away to ensure maximum possible sound or noise cancellation. 

These are all main factors and reasons in Electrical Interference in Gold Detectors

Uses of Gold Detectors

[The Ultimate Guide] Uses of Gold Detectors

Gold detectors are being used for several decades now, but over the period of time as technology evolves, people find more than one way to use and incorporate such practical devices in their lives, no matter what their professional orientation is. Here are some of the uses of gold detectors:

Detection of Landmines

Modern explosive materials comprise of many metallic components which enhance their damage level as well as give the electrical force to ignite the explosion. Landmines are one of them and because they are usually rigged underground, and can be wired or wireless. But wireless technology fails to work in presence of security protocol jammers so wire based mines are more effective. This is where gold detectors become useful to pinpoint the exact location of the mines so the security crew could safely extract on 2-4 inch depth and diffuse it. 

Pipe Detection

Pipes which are not easily found especially when buried around constructed structures or underground, then gold detectors and metal detectors could be used to see where is a metallic gas piping or sewage system so the actions could be taken according to it to ensure safety and prevention for their damage before digging around them. 

Cables and wiring

When the surrounding area comprises of populated area having several residential, commercial or industrial setups, then it becomes more likely that detecting cables and wirings become crucial. Gold metal detectors can detect and differentiate between different forms of electrical wirings including copper, aluminium wires etc. 

Stolen or Lost Metal Objects

The objects which were lost or buried accidently underground or underwater can easily be found if they are made up of gold or other detectable metals. We have seen multiple cases where people lose their jewelry item, handheld electronic devices and so on in some area they cannot tell, and these detectors come in handy that time. 

Diamond and Precious Stones in Jewelry?

Breaking up the element of surprise, yes diamond and other precious and semi precious stones from jewelry can be detected from gold detectors. How you say? Because of the possibility that diamond or those lost stones are embedded in a metallic component which holds it together with the piece of jewelry. For example if it is a diamond ring, it would be embedded in a gold or platinum base. So gold detectors are able to pick up signals for them. 

Underwater lost metal

Not only the metal dispersed under the ground but the one which was dropped into the pond or well could also be detected using many advanced underwater gold detectors. Because they are designed to work specifically in an underwater environment and pick up the magnetic rays from the lost object efficiently. According to a recent report, lacs of jewelry items are lost yearly in Pakistan. 

Treasure, Coins and Gold Nuggets

Although this might seem like the prime purpose of gold detectors, people sometimes forget how important this use is. Because it can be a mean of earning money with so much potential as the objects buried underground hundreds of years ago are hard to claim by most of the people in today’s world.

In Geological Research

Detectors can reveal various rocks with ferrous compounds or metallic layers embedded in the sediments over the period of their formation. So some of those rocks would respond to the gold detectors and these can assist in geological research. 

Cheapest Gold Detectors in Pakistan

The gold detectors are available for everyone who wants to explore the grounds and see what treasures are hidden underneath the ground surface. However investing in such heavy equipment for hobby is not easy, and starting from a beginner level equipment makes some sense as well. Here are the features which will come with the cheapest gold detectors only. 

For Recreation Only

These equipment are not very high end, thus extremely sophisticated technology required for professional level work is not available. Only the necessary functions vital for the working of a gold detector are present which would only make it much more easy to carry and helpful for recreational purposes. 

Specific Environmental Conditions

The gold detectors could only be utilized in a very low range of environmental conditions and the results would be compromised if the weather becomes unstable for example extreme temprature shifts, rain, thunderstorms etc. Also the electrical interference from surrounding metallic bodies will also change the productivity of equipment negatively.  

Very Limited Depth

The detectors advertised within affordable price range or cheap category can not perceive the depth underground to a very long extent. They may be practical to use for the distance of about a few inches only. 

Limited Display Options

The display options for the metal detectors in this category comes usually with typical analog systems, where the needle deflection shows metal detection with or without sound effects. However some models can also come with an advanced or digital LED based display. 

Technology and Coils

They detectors usually work on VLF technology and coil sizes are small with options of mono coils only, with no differentiation between ferrous and nonferrous compounds. These are some of the basic technologies which only work to detect the presence of a metallic object. Mono coil results in slightly increasing the depth potential which is a plus for this equipment. 

Time Taking

As the coil size is so small, it is very time consuming to cover an area using these detectors. The continuous swinging motions are required because of the motion based mechanism and it becomes very time consuming. 

Not Very Reliable Results

The results of the beginner level gold detectors are not in very much detail thus they are considered approximate and are not always accurate or correct. So this becomes very tough for the gold detector users to judge whether they are digging the right place or the alarm was only for a trashy material comprised of a metal. 

These are some factors which are important to keep in mind while purchasing Detectors

Most Expensive Gold Detectors in Pakistan

Gold detectors as treasure hunting equipment have an image of being very expensive and it is not completely false. Although the price range starts from about 10k, it extends all the way up to more than 400k and as many features the buyer would like to have, the more he will be willing to pay. But what are the extreme features which could be expected from top-notch metal detection equipment so far? Here is a list of features about the most expensive gold detectors and how they justify the price range. 

In-Depth Structure of Ground

These gold detectors are not only practical for finding gold deposits underground but also used surveying instruments. They have the capability of understanding the surfaces beneath the ground level such as graves, caves and cavities etc. because of the very delicate sensor-based technology they are developed on. 

Supports Extreme Environmental Conditions

These gold detectors are designed to work in extremely bad weather conditions. Especially when other detectors are unable to follow through, these special instruments go through every water based or in general any geological conditions. 

Maximum Possible Depth

If the buyer or a person interested in buying gold detectors with the maximum possible depth access underground, then it can only be promised by the most expensive gold detectors. This depth would not be compromised due to ground conditions or environmental factors. 

Comes With Premium Paid Software

The premium gold detectors are also accompanied with some superior quality software developed especially to optimize the results and output representation of the device. Many USA and Germany based companies are coming with these software solutions for their worldwide audience. After scanning the field or ground via hardware equipment, the data is exported to the systems with software support. Most of these equipment;s software is supported by desktop computers because of the higher computing power. But some of them are also available for mobile devices.   

Manufacturer’s Country of Origin

Based on the country of origin and their history for manufacturing quality products, their commitment to technological advancements as well as potential to supply globally, the product quality from  the countries can vary. The best and top of the line gold detectors are manufactured by USA and Germany. Then Canada has its presence, followed by some other Europeon countries. 

Absence of Coils

These best and expensive detectors do not work of VLF or Pulse Induction technology. Their unique technology is called Electromagnetic Radar Technology  or Electromagnetic Sensor technology. 

Indoor Testing is not Possible

The sampling and testing whether the device works indoor or not, or under fresh items, is not very effective. These highly powerful equipment works best on long buried objects only. 

Disadvantages

One of the major disadvantages of using such high tech equipment, is that it is very time taking to work on such big level. A crew might be required to do the whole project of detection, data analysis, digging, prospecting etc. First the field data is collected, then data in vast amounts is saved in some external storage device. Then that data is saved and analyzed in the device supporting the respective software for each device. Although an option to work live at the site is possible, but it is very complicated to execute. 

Uses of Most Expensive Detectors

Most expensive detectors come with a lot of fancy perks which can be easily utilized by many people from different scientific and non-scientific backgrounds all using for different purposes. Here are some of the popular purposes: 

  • By Archaeologists – the professionals who are researching older civilizations by looking out for their items buried underground as well as their lifestyle of living etc. can use these sensors to conduct underground surveys.
  • By Geologists – People researching about the Earth and what it contains, including natural rocks, sediments, cavities and what they comprise of use these radar technology based gold detectors to enhance their data collection and analysis. 
  • At Construction Sites –  Where the engineers and construction site developers want to analyze the ground they will be building some structures on, and depending of the type, quality and make up of the ground components underneath, the construction project could be effectively modified. 
  • For Pro Treasure Hunters – People who know what they are doing with treasure hunting and how large profit potential their land has, they invest in such equipment to get more efficient and precise results. 

Price Range

As the title suggests, these are the most expensive gold detectors with numerous benefits and some complexities. The price basically depends upon the brand and model the buyer chooses, but the price range usually falls between about 15,000 Euros to 50,000 Euros. 

Popular Models in Most Expensive Detectors

Some of the popular models which could be classified in the most expensive gold detector categories could be:

 

  1. OKM ABCXYZ (please edit and add some models)

[The Ultimate Guide] 6 Categories of Gold Detectors

For the ease of setting up a huge array of gold detector based products, besides categorizing them based on the levels at which they perform e.g. beginner, intermediate, advanced, deep seeking and professional etc. there is one more way. This list is according to the usage requirements of the buyer whether they would prefer to have one for gold nuggets only, one for coins and relics upto the most latest type showing data in 3D outputs. Take a look at the list to determine what are the six categories of gold detectors based on their mode of utility.   

  1.  Gold Detectors For Gold Nuggets

The gold nuggets are small metallic objects which can widely vary in shape and form as well as weight but can be considered the smallest detectable objects by gold detectors. The detectors which are equipped for gold nuggets are usually smaller in size and lighter in weight, with a small coil which is able to detect minute objects underground. The depth is very low and price point is also very basic. 

  1.  Gold Detectors For Coins and Relics

The gold detectors specializing in coins and relics are comparitively more heavier and have intermediate sized coils so they can detect bigger objects easily. That is the reason why some of them ignore very small objects. The depth is not very low because the coil size is increased and they are relatively more pricier than gold detectors for nuggets. 

  1.  Gold Detectors For Deep Seeking Purposes

When the buyers require something which can only be looked into with more advanced equipment having high depth possibilities, then deep seeking purposes are conveyed and such detectors are recommended. They are very heavy and a single person cannot carry it themselves. The depth is increased and many vital functions like ground balance, digital display etc. is present. 

  1.  Multipurpose Gold Detectors 

The gold detectors which are equipped to find small to large objects under varying depths all at the same time are called multipurpose detectors. They have several options to switch to and from in different cases as well as various interchangeable hardware attachment options are also present. 

  1.  Waterproof or Underwater Gold Detectors

The detectors which are specially designed to work in extreme weather conditions like when it is raining outside or when the users would like to check the presence of gold items under the surface of water. These type of detectors come in three variation, one the most basic form is when only the coil is waterproofed. The second one is where the hole detector including the coil, shaft and control unit is made waterproof or also known as weather proof. Last is the one which can be completely immersed below the water and it will not damage the machine or its detection functionality, these are underwater gold detectors.

  1.  3D Professional Gold Detectors

The Gold detectors which are well equipped with the most precise and best quality data output generation are 3D professional gold detectors. They have either a built in backlit digital display or can be connected to external devices through third party software which then helps generate various types of data in form of very intuitive and engaging 3D graphs. 

Which Gold Detector is Best to Buy

The gold detectors have a wide variety of models and variants which are specifically designed for a different usage situation so it becomes very crucial to decide which one will be perfect for your unique situation. However, for the ease of your decision to choose the Gold detector which is best to buy for you among all, we have classified the main requirements of your information about the unique situation into three heads, purpose, the requirement of discrimination and well as soil condition. And the purposes of buying are further classified into four sub-categories.

Purpose of Buying

The people, the area or the stories surrounding you might suggest some cues about how and why you will be requiring a new gold detector. Here are four basic reasons why you would want a detector:

  • Gold Nuggets

Gold nuggets are small chunks of gold which can be as small as the tip of a ballpoint pen and as huge as a handful. They are usually bigger than fine gold or powdered gold in particles which cannot be detected by metal detectors. 

  • Treasure Hunting

Treasure hunting includes looking for items which are usually bigger than gold nuggets and can have various sized objects including gold coins, gold relics, gold statues, etc. They are usually used at locations where you already have an idea about some buried objects.

  • Underwater

The purpose of using gold detectors solely underwater to find and grab gold items from water bodies including lakes, canals, streams, ponds, or to some extent, sea, and ocean.

 

  • Multipurpose

This is the more generalized purpose where the buyer may not know what specifically he or she wants and requires versatile equipment which can work equally fine on gold nuggets, for treasure hunting or for underwater gold prospecting. 

Requirement of Discrimination

Depending upon the area where you will be conducting the gold detection process, if other metallic objects are frequently found as trash underneath the soil or recently a construction took place, then it would be better to go for a discrimination based gold detector. But if you are sure none of the problems would persist and the area is remote where the public access is not that frequent, then a detector without discrimination will also work and would be budget friendly. 

How is the Soil

The condition of soil whether it is highly mineralized having many metallic compounds embedded in the soil particles will also make it very difficult to a budget-friendly gold detector work on such soil without creating excessively annoying noise. But in that case, using a detector with the ground balance option available would make it easier to work by canceling out the magnetic field of the highly mineralized soil. 

Difference between Gold and Metal Detectors

 

AspectsGOLD DETECTORSMETAL DETECTORS
PurposeGold detectors have a sole purpose of detecting gold objects buried underground, distinguishing them from the other metallic compounds or completely ignoring them, because they are not precious. Metal detectors have the purpose of detecting the presence of metallic objects buried in a medium whether it is ground, water or otherwise to ensure it can be extracted or taken out of the system successfully.
Frequency RangeGold detectors are specifically designed to work with higher frequencies so that they will only respond to dense and precious metals with precision, and not ignore very close to surface gold nuggets. Metal detectors are very versatile and depending upon the usage requirement and size, they can work on several frequencies and the users have the flexibility to choose a suitable one.
UsesGold detectors are very specific type of metal detection instruments which are used for the purpose of finding treasures in form of gold coins, gold nuggets or relics statues and antiques below ground, underwater or for other multiple purposes. Metal detectors are used for all purposes where the metal is required to be separated from non metal items for example for security purposes in walk through gates, in the construction industry, in the retail sector, for physical research, in production of sensitive equipment etc.
DepthBecause of the nature of gold detectors working on a higher frequency, it is very difficult for them to work on very great depths in the ground and mostly work very close to the surface of Earth starting from one inch to a few meters.Because of the versatile nature of metal detectors, they are designed to focus on all or some of the specific class of metal objects, so they can have varying depth options from very less to very high as the frequency of them varies. 
DiscriminationIn gold detectors, the feature of discrimination is very important because only one metal is the center of attention which is Gold, so it must be separated from other metals during the detection process to avoid wastage of any time. Metal detectors can be equipped with discrimination or not depending upon how the buyer intends to use it. If they want to use it for the purpose of identifying metals from nonmetals then discrimination is not necessary. But if the user requires to classify the detected metal as a certain type e.g. iron copper, aluminum or gold, then discrimination in metal detection becomes helpful.
Coil SizeCoil size has a variety of options to choose from depending upon the user’s preference, as smaller coil size will be more helpful in detecting gold nuggets, but bigger coils will be more helpful to look for bigger gold items. Coil technology is pretty much the same in both, and size has a variety of options to choose from as well. It also depends on the user’s preference, as smaller coil size will be more helpful in detecting smaller items like in security, but bigger coils will be more helpful to look for metallic items for example in construction or research. 
Major DifferenceGold detectors are a type of metal detectors where the emphasis of the detection technology is to classify whether the metal is gold or other nonprecious metals, to target and mine gold from below the surface of ground or water. Metal Detectors are a major type of detection instrument which uses a specified set of technologies to classify different types of metals or metals in general in a specific location underground or underwater which is not visible otherwise. 

 

It can be safely concluded that every gold detector is a metal detector but every metal detector is not a gold detector.