Detector being used (before-productive version without a handle)

    Underwater metal detector "DarkFish-07" allows running an explorations in extremely hard underwater environment conditions with maximally simplified service.

Dimension of UMD DarkFish-07

Characteristic features of Underwater Metal Detector:

• Range of depth: 50m (special edition: 100m)
• Mass (with batteries):1,3 kg, in water nearly zero buoyancy
• Easy, compact construction, lack of outside loose elements
• Automatic tuning for work conditions
• Servicing with single switch-key
• Signaling: optical, sonic-vibrative
• High sensitiveness irrespectively from environment (air, salty and sweet water)
• Control by microprocessor system with an opportunity to change software
• Power supply with battery cells or accu 8 x R6, time of permanent work: ca 15h

View of entire detector

Detector opened in order to exchange batteries

Principles of working

    Underwater detector uses the impuls method (PI - puls indicate) to detect metal objects which occur nearby the bobbin. Working is based on sending strong single electromagnetic impulses and measuring the 'reflexed' magnetic field which arose in order to electromagnetic induction in objects with magnetic features. This method is mightily effective in water environment, even in the case of strong salinity of water.
Detector does not have possibility to distinguish different kind of material - ferromagnetic or paramagnetic. Measuring impulses are sent circa 200 times per second, so its efficacity is almost permanence. Collected impulses are measured by microprocessor system, which compares changes of the signal level with standard magnitude. In case of detection the deviation optical and sonic flag-wagging is switched on.

Switching on the detector being hold in position ready to work

    In the moment of switching on the detector during first 2 seconds appears automatic calibration to the referral level. In case of correct tuning one should for this moment push away the bobbin of detector from alternatively metal objects.

Test in swimming pool - search

Measurement

    Detector is provided for underwater work. Special handle allows for comfortable and confident catch hold. Second handle is there to be attached on forearm. In each moment you are able to launch the detector, but the forearm handle protects it from being lost.

Test in swimming pool - free hands

    In order to protest detector from being lost you can fasten short rope (length: ca 60 cm), which should be attached to the jacket handle before diving. Detector is entirely symmetrical so it can be attached to either right or left arm. Only forearm yoke has an elastic fillet on left side. In case of necessity to turning the yoke one should lift and unfasten the yoke's lock using screwdriver and then take off the yoke, turn it and put again in the same place.
    Then you should activate detector twisting the magnetic circuit-breaker ring. At the moment of switching on, bobbin has to be kept away from the metal objects. Then comes automatic calibration of detector. After circa 2 seconds and short double signal detector is ready to work.

Test in swimming pool - searching position

Test in swimming pool - casual access through the bobbin

Notes

    Underwater work requires particular consideration and mastery in diving. Searching is an action which demands concentration and which lifts considerably the level of difficulty of diving. It is advisable to choose the place of searching which was checked earlier. Moreover in many cases searching will be run with very feeble visibility. Because of this detector has been maximally simplified having none loose-fitting elements (except from secure rope). Owning to this we do not have to distract our attention with service of detector so in emergency situation we can immediately have both hands free.

    Searching in extremely hard conditions (demersal mud) should be run with second person's insurance who uses a rope. Seeking in mud raises a cloud which limits the visibility to few centimeters. If you are not able to take an object out in several seconds you should stop searching in this place and start in another.

    When it is necessary to use equipment like shovel in searching, you better choose plastic one, because it does not disturb the running of detector and have nearly neutral buoyancy.

    In necessity of swimming to the place of searching you can comfortably place the detector under the belt holding jacket. In order to do this you should put the end of detector under the belt and shift jutting part of handle, so that detector will not prevent from diving, staying along the body with the bobbin situated near thigh.

    You should remember about fixing a protecting rope so you will not loose it accidentally.

    In detector is applied specialist microprocessor to control an electronic system of device, which tests basic functions of the device's work and signalize each faultiness. There is also possibility of updating software which controls the work. In order to do this you should, after previous notification, remove electronic printed circuit from detector and send it in save envelope to producer. After updating software will be sent back. During guarantee period this procedure is free.

    On electronic circuit there is dip-switch more or less in the middle. Changing position of switch [1] causes reversing the signal colors during detector's work. The signaling variant which is used depends on the personal fancy.

    Producer does not bear responsibility for consequences of finding dangerous objects like weapon, blinds, misfires etc. and possible damages of monuments, relics and archaeological positions.
Underwater Metal Detector cannot be used by people with heart stimulator or other medical appliances.

Brassy knuckle of gassy lamp found in polish lake