Did you know that the first metal detector was created in 1925? The inventor, Dr Fischer was a German immigrant living in California. From his garage, he brought to the world the first metal detector. Since then, people never stopped buying them and looking for gold nuggets. Nowadays, these machines have become very advanced compared to the old ones. They’re lighter, more sensitive, energy efficient and have many features that help you with your quest.
Types of Metal Detectors
Pulse Induction Detectors
This is a unique type of metal detector that differs from the rest in one way. As you may know, VLF detectors use two coils, but the practical pulse induction detector uses only a single coil. This coil transmits and receives electrical currents at the same time on its own. The pulses that it receives can vary between 100 and 500 pulses in just one second. This means that each pulse only lasts a millisecond.
The detector measures the time between each pulse, and when the pulses decrease it means that the detector detected some kind of metal underneath. They fall into the more expensive category, starting from $1,500 and more. This detector is more resistant to mineralisation than the other ones. That’s why it’s better to use it if you’re searching on rivers, beaches or even underwater.
It’s not recommended that you use it in the city because it can’t make a distinction between nails and coins or gold for example. You’ll find what you’re looking for, but it’ll take a lot of time and patience. The pulse induction detector is designed with a nice depth of around 31cm below ground, which is a good penetration level. One disadvantage is that it can be heavy to carry around.
Very Low Frequency
This is one of the most common types of detectors. The VLF has two coils, one is for the transmitter and the other is for the receiver. The transmitter coil sends electrical currents below the ground and, if there are metal objects underneath, they’ll create their own magnetic field. Now the receiver coil detects this magnetic field and transfers the signals into the control box for you to see.
The display will show an ID on the screen, and you’ll get one beep or many consecutive beeps. The VLF detector uses an advanced, yet simple technology. It’s also one of the cheapest options on the market and anyone can afford it. It has a long battery life and it’s easy to use. Plus, it’s lightweight and durable which means even kids can use it. This detector can be waterproof, and you can use it to find jewellery, coins or relics.
These detectors are not limited to one frequency as the VLF ones are. They have the ability to scan for bigger and smaller items on different levels of depth at the same time. This is thanks to the multi-frequency function which makes them fall into the middle of the price points between the VLF and PI detector. They have a nice depth level of 15-20cm and also react better on mineralised soils. However, don’t confuse them with selectable frequency which use multiple frequencies but not at the same time as the multi-frequency detector.
Know Your Metal Detector
The machine’s sensitivity, frequency, and discrimination characteristics are all controlled by the coil. The double-D coil is called that way because of how it resembles two overlapping Ds. This is a good one for searching for goods in highly mineralised soils. It has the ability to locate little objects on deeper grounds. The concentric coil has two circles—an inner circle and an outer circle—and powerful detecting abilities. Also, mono-loop coils are used in the pulse induction detector.
Ever wonder how far down most metal detectors can go? That depends on the coil of course. The search depth is directly correlated with the coil’s diameter. In other words, a huge coil has the capacity to stretch significantly past 22 cm. The range for a medium-sized coil is 17–22 cm and only 15cm with little ones. Therefore, if you believe your targets go deeper, choose machines with larger coils.
In your quest for gold or some kind of metal, the discrimination option can be quite helpful. This is an option that lets you ignore the metals you don’t want to find. By doing this, you’ll save a lot of time and effort. People often don’t know about this option and find a lot of aluminium caps. If you’re interested in having this option, ask your seller and they’ll explain everything you need to know.
This feature demonstrates the capability of your pulse induction detector or any of the other two options to catch smaller targets. If you’re constantly looking for smaller objects this is the right feature to have. It’ll make things much easier. So, we recommend getting a detector with a high-sensibility sensor.
Each detector uses a certain frequency or multiple frequencies to work. The frequency affects both sensitivity and depth. So, if you have a low-frequency machine that penetrates deeper, it may not recognise smaller targets. Or it can be sensitive to smaller objects on a higher frequency, but it won’t go very deep.
Things to Consider When Buying
Mineralisation of the Soil
Mineralization is a crucial element that affects the entire search process and your rewards. Some soils include metal, which might cause the detector to respond magnetically. If this occurs, the detector won’t show you where the gold or the specific metal you’re looking for is located in the ground. Lead might be a good starting point for you to consider. There is a strong likelihood that gold is nearby if you find lead.
If you’re a beginner in this industry, it is not recommended that you get an expensive detector for starters. You first need to get used to it, comprehend how it works, know its strong and weak sides and then move forward to buying something more expensive. You might not even like it and it won’t turn into a hobby or a passion. A more expensive machine might make you happier and give you many rewards, but if you don’t have the budget for it don’t bet yourself over it. Make a list of the features that are important to you according to the place in Australia you’ll be tracing and stick to it.