A Beginners Guide to Detecting /Club info
Since the late 1960's, due to the advent of modern electronic detecting equipment, the hobby of metal detecting has been available to many people. The opportunity to find objects of intrinsic and financial value, which may date back hundred s or maybe thousands of years, is very appealing.
Metal detecting does not have to be an expensive hobby. Many machines are available for less than a £100.00 and as your interest grows, then more sophisticated machines are available to take you through your 'career' in detecting.
Listed below are the most common questions asked by beginners to the hobby.
Buying a Machine
Your first machine should be what is sometimes described as a 'switch-on-and-go' machine (whether motion or non-motion). In other words a machine that can be understood and in operation within minutes of the buyer unpacking it. Usually this means that the machine has two primary controls only, sensitivity and discrimination (both described later on). Some machines have sensitivity and beach and inland controls, no matter; what is important is the ease of understanding of the machine and what it can do. Do not assume that a simple machine is necessarily a cheap or basic machine. Many good quality machines used by experienced detectors are switch-on-and-go machines, and find as much as machines with more complex functions.
How complex is a metal detector to operate.
The answer to this is on a sliding scale, beginner's machines are designed to be easy to operate and understand and will have you detecting within a few minute. However as you develop confidence and knowledge you may wish to move beyond the limitations of these machines, and as your understanding of the principles behind the hobby improves you will want to have a machine which you can adjust to the settings you require. As with many things in life it is down to the nature of the individual and how they like to learn. Some require the ability to move up through machines as their knowledge improves, some wish to start with a complex machine and then learn over a period of time all its functions. Also it is important to remember where your are detecting, as manufacturers offer different types of machine for specialist beach detection (particularly if you wish to specialize in detecting by or in sea water) as opposed to land detection or land/beach machines. The choice is yours, however please be assured that we will endeavor to guide you to the type of machine which is right for you.
Metal detectors - how they work.
We won't bore you with the general principles behind a metal detectors method of locating metallic objects (no physics lesson needed here!), but an understanding of the different systems available is important.
Metal detectors are split into two basis types: motion and non-motion machines.
The difference between Motion & Non-Motion detectors
Non - Motion are the older of the two main technologies types, however there is no good or bad regarding the two systems as each has its own pros and cons. They are merely different and it comes down to personal taste as to which you will use.
These machines do not require side-to-side 'sweeping' movements in the same way as a motion detector, in order to find a metallic object. Making them particularly useful when working in tight areas.
Non-Motion detectors produce a with a faint hum as you scan the ground, giving a raised tone as you pass the head of the machine over a metallic object. Many detectorists like these machines as the change in tone gives a mental picture of the size of the find below the surface, as the tone will change when you approach the object and be maintained until you pass over the find, then the tone falls to it's original level.
These machines are tuned manually in a similar way to tuning a radio to a particular station. They sometimes need to be retuned as the signal may have drifted away from the desired station (think medium wave) and in effect the same thing happens with a Non-Motion detector, the situation is simply remedied be re-tuning the machine a retune button is usually provided for this function.
Motion detectors are the more recent of the two systems first appeared in the early 1980's. Before this, all detectors were Non-Motion
Motion detectors run silently as you scan the ground (no hum), unlike non-motion detectors they are automatically tuned machines. The search coil has to be in motion in order to register an object, this is done by sweeping the machine from side-to-side over the ground whist walking forward or once an object is located then sweeping whilst stationary. When you pass the head of the machine over a metallic object it will inform you of the object's presence 'with a bleep tone' but remember when the head stops moving, so will the signal heard from the detectoreven if directly under the coil. As a result many motion detectors have a "pinpoint" switch; this will allow a temporary change to Non-Motion Mode and will allow more accurate location targeting (It is possible to locate without a pinpoint using the crosshair method). These machines also have the ability to discriminate between different metals (see discrimination). It would be fair to say that most metal detectors sold today are motion detectors
Where to search first
Metal detecting can be done in many places, however one of the best places to start is in your own garden. This is a good place to try out your new purchase and to learn the capabilities of your machine. Please remember as a responsible detectorist you must ensure that when you detect on land/beach other than your own, that you are allowed to be there. Regarding public land make sure you check you are allowed to detect on it first with the appropriate authorities, and with private land always seek the land owner's permission first! Also remember to back fill any holes you have dug up.
Learning what a machine can do
Try burying different metal objects (iron, brass, copper, aluminum, gold, silver etc) just under the surface (you can dig them up later) in order to learn to set your machine and understand what your machine is telling you. This can be done in the garden or you can do air tests on a wooden table set away from any metal objects.
Discrimination - an explanation
A detector with discrimination has the ability to ignore smaller ferrous (iron or containing iron) objects, like nails for example. The machine can usually be adjusted to knock out the majority of these objects (subject to how large they are) and also objects in the non-ferrous range like silver foil and ring pulls. However a word of caution here. A number of valuable objects also sit in this range e.g. gold rings (9ct), and a number of hammered coins containing silver. Therefore to discriminate ring pulls you can also discriminate valuable items as well !. Many detectorists will usually run their machines in a mode which will knock out iron objects, but will allow others though. Manufacturers have devised many different ways of indicating the type of metal below the surface, audio discrimination (different pitches dependent on the conductivity of the metal (e.g. Iron = low pitch tone and moving up though the range to a high pitch tone for copper), scales which give a numeric value (e.g. Iron = 1 to 5 and copper =30).These numerical scales will differ between each manufacture, however the principle remains the same for each. These functions are useful as they can give an indication of whether to dig or not. When detecting in contaminated (iron rich) sites, you need to move through the area slowly and listen and look at the information the machine is giving with your full attention as iron may be close to and could 'masking' the signal of
How deep can a machine detect targets?
The 64,000 Dollar question! However the answer is not completely straight forward.
A number of factors come in to the answer.
1, Soil conditions: moisture in the soil and mineralisation will affect the depth a machine will reach; also dry and mineralised soil will have an adverse affect. Soil which is compacted usually gives better depth, than aerated soil (some machines don't perform as well in these conditions.)
2, How an object is laying: simply put an object (coin for example) on its side is harder to find at depth than an object lying flat. Therefore, in general, the greater the available surface available to the signals the greater the depth it will be found at.
3, The size of object: the larger the object, the greater the mass and surface area available to be detected at depth.
4, The type of object: objects such as rings which are complete all the way round (complete circle) are picked up by the detector as a 'solid object' and can be found at a greater depth than say a bracelet with a break in it (not a complete circle) even if the bracelet has a higher metal content.
As an indication locating a:
" coin sized object should be possible at anything between 10cm(4") to 22.5cm(9"),
" with much larger objects up to 1 metre (39").
However please remember that this depends on the machine you use and the variables of ground condition at the time.
Mineralisation/Ground Effect Explained
In the ground sometimes as a result of man made actions ( mining, farming, industrial activity), or natural occurrence, you will find varying amounts of iron oxide or other chemical deposits, this what is referred to as mineralised ground. Some areas can be heavily mineralised and some less so. The result of this as far as metal detectors are concerned, is something called ground effect. The machine actually sees the ground as a target object and this target object needs to be cut out or neutralized in order to find proper targets. Most motion machines are able to do so automatically; however on a non motion machine that features a ground exclude control this will need to be adjusted until the machine's response does not alter when the search head is lowered to the ground. Please note beaches have a ground effect caused by the electro- conductivity of salt water
Detecting on beach and land - can you use the same machine?
Dry sand can be detected on in the same way as earth (inland sites) so the answer is Yes.
Wet sand, as mentioned earlier is highly mineralised and is therefore different. As it is conductive, it is usually best to use non-motion machines, for serious beach detecting a pulse induction machine will provide the best results. Motion machines are not usually as effective; however some motion machines have been produced to be able to cope with these conditions. Some detectorists have two machines, one for wet sand, and one for everything else.
Again we will guide as to the best choice for you.
Do you need a license to use a metal detector?.
No, the Home Office ended the need for licenses in 1980.
How do I conduct myself as a Detectorist ?
We refer you to the following website for an agreed code of conductivity
http://www.finds.org.uk/documents/CofP1.pdf (England and Wales)
What do I do if I find something of value and where do I stand legally?
We refer you to the following websites to give the best answer to these questions.
http://www.opsi.gov.uk/ACTS/acts1996/1996024.htm Treasure Act (1996)
www.finds.org.uk Portable Antiquities Scheme
In Scotland
www.nms.ac.uk National Museum of Scotland
What do I do to avoid damaging a find and to preserve it?
We refer you to the following website
www.finds.org.uk Portable Antiquities Scheme
What else would I need to go detecting?
" Power-Batteries rechargeable (charger required) or non-rechargeable
" Search head Cover/Coil Cover -protects the search head of the machine from wear and tear, remember it is cheaper to replace a coil cover than a search head.
" Headphones either a basic pair (sometimes supplied as part of the package when you buy the machine) or more expensive ones (better sound quality), either way they, cut out background noise, and save on machine battery life compared to when you use the machines speaker alone.
" Digger- A digging tool, spade, trowel etc, in order to excavate you find, don't forget to backfill!
What beginner's literature would you suggest?
The Beginners Guide to Metal Detecting Julian Evan - Hart & Dave Stuckey (We have in stock)
Portable antiquities Advice Notes
Machine Instruction Manual and or Video/DVD
